projs/20161008_web_page_thumbnail_make/thumbnails_pics_make.php

<?php
//--------------------------------------------------------------------------------
//thumbnails_make.php, v0.1a, Copyright David T. Ashley, 2016
//--------------------------------------------------------------------------------
//-------------------------------------------------------------------------------------------------
//Copyright 2016 David T. Ashley
//-------------------------------------------------------------------------------------------------
//This source code and any program in which it is compiled/used is provided under the GNU GENERAL
//PUBLIC LICENSE, Version 3, full license text below.
//-------------------------------------------------------------------------------------------------
//                    GNU GENERAL PUBLIC LICENSE
//                       Version 3, 29 June 2007
//
// Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
// Everyone is permitted to copy and distribute verbatim copies
// of this license document, but changing it is not allowed.
//
//                            Preamble
//
//  The GNU General Public License is a free, copyleft license for
//software and other kinds of works.
//
//  The licenses for most software and other practical works are designed
//to take away your freedom to share and change the works.  By contrast,
//the GNU General Public License is intended to guarantee your freedom to
//share and change all versions of a program--to make sure it remains free
//software for all its users.  We, the Free Software Foundation, use the
//GNU General Public License for most of our software; it applies also to
//any other work released this way by its authors.  You can apply it to
//your programs, too.
//
//  When we speak of free software, we are referring to freedom, not
//price.  Our General Public Licenses are designed to make sure that you
//have the freedom to distribute copies of free software (and charge for
//them if you wish), that you receive source code or can get it if you
//want it, that you can change the software or use pieces of it in new
//free programs, and that you know you can do these things.
//
//  To protect your rights, we need to prevent others from denying you
//these rights or asking you to surrender the rights.  Therefore, you have
//certain responsibilities if you distribute copies of the software, or if
//you modify it: responsibilities to respect the freedom of others.
//
//  For example, if you distribute copies of such a program, whether
//gratis or for a fee, you must pass on to the recipients the same
//freedoms that you received.  You must make sure that they, too, receive
//or can get the source code.  And you must show them these terms so they
//know their rights.
//
//  Developers that use the GNU GPL protect your rights with two steps:
//(1) assert copyright on the software, and (2) offer you this License
//giving you legal permission to copy, distribute and/or modify it.
//
//  For the developers' and authors' protection, the GPL clearly explains
//that there is no warranty for this free software.  For both users' and
//authors' sake, the GPL requires that modified versions be marked as
//changed, so that their problems will not be attributed erroneously to
//authors of previous versions.
//
//  Some devices are designed to deny users access to install or run
//modified versions of the software inside them, although the manufacturer
//can do so.  This is fundamentally incompatible with the aim of
//protecting users' freedom to change the software.  The systematic
//pattern of such abuse occurs in the area of products for individuals to
//use, which is precisely where it is most unacceptable.  Therefore, we
//have designed this version of the GPL to prohibit the practice for those
//products.  If such problems arise substantially in other domains, we
//stand ready to extend this provision to those domains in future versions
//of the GPL, as needed to protect the freedom of users.
//
//  Finally, every program is threatened constantly by software patents.
//States should not allow patents to restrict development and use of
//software on general-purpose computers, but in those that do, we wish to
//avoid the special danger that patents applied to a free program could
//make it effectively proprietary.  To prevent this, the GPL assures that
//patents cannot be used to render the program non-free.
//
//  The precise terms and conditions for copying, distribution and
//modification follow.
//
//                       TERMS AND CONDITIONS
//
//  0. Definitions.
//
//  "This License" refers to version 3 of the GNU General Public License.
//
//  "Copyright" also means copyright-like laws that apply to other kinds of
//works, such as semiconductor masks.
//
//  "The Program" refers to any copyrightable work licensed under this
//License.  Each licensee is addressed as "you".  "Licensees" and
//"recipients" may be individuals or organizations.
//
//  To "modify" a work means to copy from or adapt all or part of the work
//in a fashion requiring copyright permission, other than the making of an
//exact copy.  The resulting work is called a "modified version" of the
//earlier work or a work "based on" the earlier work.
//
//  A "covered work" means either the unmodified Program or a work based
//on the Program.
//
//  To "propagate" a work means to do anything with it that, without
//permission, would make you directly or secondarily liable for
//infringement under applicable copyright law, except executing it on a
//computer or modifying a private copy.  Propagation includes copying,
//distribution (with or without modification), making available to the
//public, and in some countries other activities as well.
//
//  To "convey" a work means any kind of propagation that enables other
//parties to make or receive copies.  Mere interaction with a user through
//a computer network, with no transfer of a copy, is not conveying.
//
//  An interactive user interface displays "Appropriate Legal Notices"
//to the extent that it includes a convenient and prominently visible
//feature that (1) displays an appropriate copyright notice, and (2)
//tells the user that there is no warranty for the work (except to the
//extent that warranties are provided), that licensees may convey the
//work under this License, and how to view a copy of this License.  If
//the interface presents a list of user commands or options, such as a
//menu, a prominent item in the list meets this criterion.
//
//  1. Source Code.
//
//  The "source code" for a work means the preferred form of the work
//for making modifications to it.  "Object code" means any non-source
//form of a work.
//
//  A "Standard Interface" means an interface that either is an official
//standard defined by a recognized standards body, or, in the case of
//interfaces specified for a particular programming language, one that
//is widely used among developers working in that language.
//
//  The "System Libraries" of an executable work include anything, other
//than the work as a whole, that (a) is included in the normal form of
//packaging a Major Component, but which is not part of that Major
//Component, and (b) serves only to enable use of the work with that
//Major Component, or to implement a Standard Interface for which an
//implementation is available to the public in source code form.  A
//"Major Component", in this context, means a major essential component
//(kernel, window system, and so on) of the specific operating system
//(if any) on which the executable work runs, or a compiler used to
//produce the work, or an object code interpreter used to run it.
//
//  The "Corresponding Source" for a work in object code form means all
//the source code needed to generate, install, and (for an executable
//work) run the object code and to modify the work, including scripts to
//control those activities.  However, it does not include the work's
//System Libraries, or general-purpose tools or generally available free
//programs which are used unmodified in performing those activities but
//which are not part of the work.  For example, Corresponding Source
//includes interface definition files associated with source files for
//the work, and the source code for shared libraries and dynamically
//linked subprograms that the work is specifically designed to require,
//such as by intimate data communication or control flow between those
//subprograms and other parts of the work.
//
//  The Corresponding Source need not include anything that users
//can regenerate automatically from other parts of the Corresponding
//Source.
//
//  The Corresponding Source for a work in source code form is that
//same work.
//
//  2. Basic Permissions.
//
//  All rights granted under this License are granted for the term of
//copyright on the Program, and are irrevocable provided the stated
//conditions are met.  This License explicitly affirms your unlimited
//permission to run the unmodified Program.  The output from running a
//covered work is covered by this License only if the output, given its
//content, constitutes a covered work.  This License acknowledges your
//rights of fair use or other equivalent, as provided by copyright law.
//
//  You may make, run and propagate covered works that you do not
//convey, without conditions so long as your license otherwise remains
//in force.  You may convey covered works to others for the sole purpose
//of having them make modifications exclusively for you, or provide you
//with facilities for running those works, provided that you comply with
//the terms of this License in conveying all material for which you do
//not control copyright.  Those thus making or running the covered works
//for you must do so exclusively on your behalf, under your direction
//and control, on terms that prohibit them from making any copies of
//your copyrighted material outside their relationship with you.
//
//  Conveying under any other circumstances is permitted solely under
//the conditions stated below.  Sublicensing is not allowed; section 10
//makes it unnecessary.
//
//  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
//
//  No covered work shall be deemed part of an effective technological
//measure under any applicable law fulfilling obligations under article
//11 of the WIPO copyright treaty adopted on 20 December 1996, or
//similar laws prohibiting or restricting circumvention of such
//measures.
//
//  When you convey a covered work, you waive any legal power to forbid
//circumvention of technological measures to the extent such circumvention
//is effected by exercising rights under this License with respect to
//the covered work, and you disclaim any intention to limit operation or
//modification of the work as a means of enforcing, against the work's
//users, your or third parties' legal rights to forbid circumvention of
//technological measures.
//
//  4. Conveying Verbatim Copies.
//
//  You may convey verbatim copies of the Program's source code as you
//receive it, in any medium, provided that you conspicuously and
//appropriately publish on each copy an appropriate copyright notice;
//keep intact all notices stating that this License and any
//non-permissive terms added in accord with section 7 apply to the code;
//keep intact all notices of the absence of any warranty; and give all
//recipients a copy of this License along with the Program.
//
//  You may charge any price or no price for each copy that you convey,
//and you may offer support or warranty protection for a fee.
//
//  5. Conveying Modified Source Versions.
//
//  You may convey a work based on the Program, or the modifications to
//produce it from the Program, in the form of source code under the
//terms of section 4, provided that you also meet all of these conditions:
//
//    a) The work must carry prominent notices stating that you modified
//    it, and giving a relevant date.
//
//    b) The work must carry prominent notices stating that it is
//    released under this License and any conditions added under section
//    7.  This requirement modifies the requirement in section 4 to
//    "keep intact all notices".
//
//    c) You must license the entire work, as a whole, under this
//    License to anyone who comes into possession of a copy.  This
//    License will therefore apply, along with any applicable section 7
//    additional terms, to the whole of the work, and all its parts,
//    regardless of how they are packaged.  This License gives no
//    permission to license the work in any other way, but it does not
//    invalidate such permission if you have separately received it.
//
//    d) If the work has interactive user interfaces, each must display
//    Appropriate Legal Notices; however, if the Program has interactive
//    interfaces that do not display Appropriate Legal Notices, your
//    work need not make them do so.
//
//  A compilation of a covered work with other separate and independent
//works, which are not by their nature extensions of the covered work,
//and which are not combined with it such as to form a larger program,
//in or on a volume of a storage or distribution medium, is called an
//"aggregate" if the compilation and its resulting copyright are not
//used to limit the access or legal rights of the compilation's users
//beyond what the individual works permit.  Inclusion of a covered work
//in an aggregate does not cause this License to apply to the other
//parts of the aggregate.
//
//  6. Conveying Non-Source Forms.
//
//  You may convey a covered work in object code form under the terms
//of sections 4 and 5, provided that you also convey the
//machine-readable Corresponding Source under the terms of this License,
//in one of these ways:
//
//    a) Convey the object code in, or embodied in, a physical product
//    (including a physical distribution medium), accompanied by the
//    Corresponding Source fixed on a durable physical medium
//    customarily used for software interchange.
//
//    b) Convey the object code in, or embodied in, a physical product
//    (including a physical distribution medium), accompanied by a
//    written offer, valid for at least three years and valid for as
//    long as you offer spare parts or customer support for that product
//    model, to give anyone who possesses the object code either (1) a
//    copy of the Corresponding Source for all the software in the
//    product that is covered by this License, on a durable physical
//    medium customarily used for software interchange, for a price no
//    more than your reasonable cost of physically performing this
//    conveying of source, or (2) access to copy the
//    Corresponding Source from a network server at no charge.
//
//    c) Convey individual copies of the object code with a copy of the
//    written offer to provide the Corresponding Source.  This
//    alternative is allowed only occasionally and noncommercially, and
//    only if you received the object code with such an offer, in accord
//    with subsection 6b.
//
//    d) Convey the object code by offering access from a designated
//    place (gratis or for a charge), and offer equivalent access to the
//    Corresponding Source in the same way through the same place at no
//    further charge.  You need not require recipients to copy the
//    Corresponding Source along with the object code.  If the place to
//    copy the object code is a network server, the Corresponding Source
//    may be on a different server (operated by you or a third party)
//    that supports equivalent copying facilities, provided you maintain
//    clear directions next to the object code saying where to find the
//    Corresponding Source.  Regardless of what server hosts the
//    Corresponding Source, you remain obligated to ensure that it is
//    available for as long as needed to satisfy these requirements.
//
//    e) Convey the object code using peer-to-peer transmission, provided
//    you inform other peers where the object code and Corresponding
//    Source of the work are being offered to the general public at no
//    charge under subsection 6d.
//
//  A separable portion of the object code, whose source code is excluded
//from the Corresponding Source as a System Library, need not be
//included in conveying the object code work.
//
//  A "User Product" is either (1) a "consumer product", which means any
//tangible personal property which is normally used for personal, family,
//or household purposes, or (2) anything designed or sold for incorporation
//into a dwelling.  In determining whether a product is a consumer product,
//doubtful cases shall be resolved in favor of coverage.  For a particular
//product received by a particular user, "normally used" refers to a
//typical or common use of that class of product, regardless of the status
//of the particular user or of the way in which the particular user
//actually uses, or expects or is expected to use, the product.  A product
//is a consumer product regardless of whether the product has substantial
//commercial, industrial or non-consumer uses, unless such uses represent
//the only significant mode of use of the product.
//
//  "Installation Information" for a User Product means any methods,
//procedures, authorization keys, or other information required to install
//and execute modified versions of a covered work in that User Product from
//a modified version of its Corresponding Source.  The information must
//suffice to ensure that the continued functioning of the modified object
//code is in no case prevented or interfered with solely because
//modification has been made.
//
//  If you convey an object code work under this section in, or with, or
//specifically for use in, a User Product, and the conveying occurs as
//part of a transaction in which the right of possession and use of the
//User Product is transferred to the recipient in perpetuity or for a
//fixed term (regardless of how the transaction is characterized), the
//Corresponding Source conveyed under this section must be accompanied
//by the Installation Information.  But this requirement does not apply
//if neither you nor any third party retains the ability to install
//modified object code on the User Product (for example, the work has
//been installed in ROM).
//
//  The requirement to provide Installation Information does not include a
//requirement to continue to provide support service, warranty, or updates
//for a work that has been modified or installed by the recipient, or for
//the User Product in which it has been modified or installed.  Access to a
//network may be denied when the modification itself materially and
//adversely affects the operation of the network or violates the rules and
//protocols for communication across the network.
//
//  Corresponding Source conveyed, and Installation Information provided,
//in accord with this section must be in a format that is publicly
//documented (and with an implementation available to the public in
//source code form), and must require no special password or key for
//unpacking, reading or copying.
//
//  7. Additional Terms.
//
//  "Additional permissions" are terms that supplement the terms of this
//License by making exceptions from one or more of its conditions.
//Additional permissions that are applicable to the entire Program shall
//be treated as though they were included in this License, to the extent
//that they are valid under applicable law.  If additional permissions
//apply only to part of the Program, that part may be used separately
//under those permissions, but the entire Program remains governed by
//this License without regard to the additional permissions.
//
//  When you convey a copy of a covered work, you may at your option
//remove any additional permissions from that copy, or from any part of
//it.  (Additional permissions may be written to require their own
//removal in certain cases when you modify the work.)  You may place
//additional permissions on material, added by you to a covered work,
//for which you have or can give appropriate copyright permission.
//
//  Notwithstanding any other provision of this License, for material you
//add to a covered work, you may (if authorized by the copyright holders of
//that material) supplement the terms of this License with terms:
//
//    a) Disclaiming warranty or limiting liability differently from the
//    terms of sections 15 and 16 of this License; or
//
//    b) Requiring preservation of specified reasonable legal notices or
//    author attributions in that material or in the Appropriate Legal
//    Notices displayed by works containing it; or
//
//    c) Prohibiting misrepresentation of the origin of that material, or
//    requiring that modified versions of such material be marked in
//    reasonable ways as different from the original version; or
//
//    d) Limiting the use for publicity purposes of names of licensors or
//    authors of the material; or
//
//    e) Declining to grant rights under trademark law for use of some
//    trade names, trademarks, or service marks; or
//
//    f) Requiring indemnification of licensors and authors of that
//    material by anyone who conveys the material (or modified versions of
//    it) with contractual assumptions of liability to the recipient, for
//    any liability that these contractual assumptions directly impose on
//    those licensors and authors.
//
//  All other non-permissive additional terms are considered "further
//restrictions" within the meaning of section 10.  If the Program as you
//received it, or any part of it, contains a notice stating that it is
//governed by this License along with a term that is a further
//restriction, you may remove that term.  If a license document contains
//a further restriction but permits relicensing or conveying under this
//License, you may add to a covered work material governed by the terms
//of that license document, provided that the further restriction does
//not survive such relicensing or conveying.
//
//  If you add terms to a covered work in accord with this section, you
//must place, in the relevant source files, a statement of the
//additional terms that apply to those files, or a notice indicating
//where to find the applicable terms.
//
//  Additional terms, permissive or non-permissive, may be stated in the
//form of a separately written license, or stated as exceptions;
//the above requirements apply either way.
//
//  8. Termination.
//
//  You may not propagate or modify a covered work except as expressly
//provided under this License.  Any attempt otherwise to propagate or
//modify it is void, and will automatically terminate your rights under
//this License (including any patent licenses granted under the third
//paragraph of section 11).
//
//  However, if you cease all violation of this License, then your
//license from a particular copyright holder is reinstated (a)
//provisionally, unless and until the copyright holder explicitly and
//finally terminates your license, and (b) permanently, if the copyright
//holder fails to notify you of the violation by some reasonable means
//prior to 60 days after the cessation.
//
//  Moreover, your license from a particular copyright holder is
//reinstated permanently if the copyright holder notifies you of the
//violation by some reasonable means, this is the first time you have
//received notice of violation of this License (for any work) from that
//copyright holder, and you cure the violation prior to 30 days after
//your receipt of the notice.
//
//  Termination of your rights under this section does not terminate the
//licenses of parties who have received copies or rights from you under
//this License.  If your rights have been terminated and not permanently
//reinstated, you do not qualify to receive new licenses for the same
//material under section 10.
//
//  9. Acceptance Not Required for Having Copies.
//
//  You are not required to accept this License in order to receive or
//run a copy of the Program.  Ancillary propagation of a covered work
//occurring solely as a consequence of using peer-to-peer transmission
//to receive a copy likewise does not require acceptance.  However,
//nothing other than this License grants you permission to propagate or
//modify any covered work.  These actions infringe copyright if you do
//not accept this License.  Therefore, by modifying or propagating a
//covered work, you indicate your acceptance of this License to do so.
//
//  10. Automatic Licensing of Downstream Recipients.
//
//  Each time you convey a covered work, the recipient automatically
//receives a license from the original licensors, to run, modify and
//propagate that work, subject to this License.  You are not responsible
//for enforcing compliance by third parties with this License.
//
//  An "entity transaction" is a transaction transferring control of an
//organization, or substantially all assets of one, or subdividing an
//organization, or merging organizations.  If propagation of a covered
//work results from an entity transaction, each party to that
//transaction who receives a copy of the work also receives whatever
//licenses to the work the party's predecessor in interest had or could
//give under the previous paragraph, plus a right to possession of the
//Corresponding Source of the work from the predecessor in interest, if
//the predecessor has it or can get it with reasonable efforts.
//
//  You may not impose any further restrictions on the exercise of the
//rights granted or affirmed under this License.  For example, you may
//not impose a license fee, royalty, or other charge for exercise of
//rights granted under this License, and you may not initiate litigation
//(including a cross-claim or counterclaim in a lawsuit) alleging that
//any patent claim is infringed by making, using, selling, offering for
//sale, or importing the Program or any portion of it.
//
//  11. Patents.
//
//  A "contributor" is a copyright holder who authorizes use under this
//License of the Program or a work on which the Program is based.  The
//work thus licensed is called the contributor's "contributor version".
//
//  A contributor's "essential patent claims" are all patent claims
//owned or controlled by the contributor, whether already acquired or
//hereafter acquired, that would be infringed by some manner, permitted
//by this License, of making, using, or selling its contributor version,
//but do not include claims that would be infringed only as a
//consequence of further modification of the contributor version.  For
//purposes of this definition, "control" includes the right to grant
//patent sublicenses in a manner consistent with the requirements of
//this License.
//
//  Each contributor grants you a non-exclusive, worldwide, royalty-free
//patent license under the contributor's essential patent claims, to
//make, use, sell, offer for sale, import and otherwise run, modify and
//propagate the contents of its contributor version.
//
//  In the following three paragraphs, a "patent license" is any express
//agreement or commitment, however denominated, not to enforce a patent
//(such as an express permission to practice a patent or covenant not to
//sue for patent infringement).  To "grant" such a patent license to a
//party means to make such an agreement or commitment not to enforce a
//patent against the party.
//
//  If you convey a covered work, knowingly relying on a patent license,
//and the Corresponding Source of the work is not available for anyone
//to copy, free of charge and under the terms of this License, through a
//publicly available network server or other readily accessible means,
//then you must either (1) cause the Corresponding Source to be so
//available, or (2) arrange to deprive yourself of the benefit of the
//patent license for this particular work, or (3) arrange, in a manner
//consistent with the requirements of this License, to extend the patent
//license to downstream recipients.  "Knowingly relying" means you have
//actual knowledge that, but for the patent license, your conveying the
//covered work in a country, or your recipient's use of the covered work
//in a country, would infringe one or more identifiable patents in that
//country that you have reason to believe are valid.
//
//  If, pursuant to or in connection with a single transaction or
//arrangement, you convey, or propagate by procuring conveyance of, a
//covered work, and grant a patent license to some of the parties
//receiving the covered work authorizing them to use, propagate, modify
//or convey a specific copy of the covered work, then the patent license
//you grant is automatically extended to all recipients of the covered
//work and works based on it.
//
//  A patent license is "discriminatory" if it does not include within
//the scope of its coverage, prohibits the exercise of, or is
//conditioned on the non-exercise of one or more of the rights that are
//specifically granted under this License.  You may not convey a covered
//work if you are a party to an arrangement with a third party that is
//in the business of distributing software, under which you make payment
//to the third party based on the extent of your activity of conveying
//the work, and under which the third party grants, to any of the
//parties who would receive the covered work from you, a discriminatory
//patent license (a) in connection with copies of the covered work
//conveyed by you (or copies made from those copies), or (b) primarily
//for and in connection with specific products or compilations that
//contain the covered work, unless you entered into that arrangement,
//or that patent license was granted, prior to 28 March 2007.
//
//  Nothing in this License shall be construed as excluding or limiting
//any implied license or other defenses to infringement that may
//otherwise be available to you under applicable patent law.
//
//  12. No Surrender of Others' Freedom.
//
//  If conditions are imposed on you (whether by court order, agreement or
//otherwise) that contradict the conditions of this License, they do not
//excuse you from the conditions of this License.  If you cannot convey a
//covered work so as to satisfy simultaneously your obligations under this
//License and any other pertinent obligations, then as a consequence you may
//not convey it at all.  For example, if you agree to terms that obligate you
//to collect a royalty for further conveying from those to whom you convey
//the Program, the only way you could satisfy both those terms and this
//License would be to refrain entirely from conveying the Program.
//
//  13. Use with the GNU Affero General Public License.
//
//  Notwithstanding any other provision of this License, you have
//permission to link or combine any covered work with a work licensed
//under version 3 of the GNU Affero General Public License into a single
//combined work, and to convey the resulting work.  The terms of this
//License will continue to apply to the part which is the covered work,
//but the special requirements of the GNU Affero General Public License,
//section 13, concerning interaction through a network will apply to the
//combination as such.
//
//  14. Revised Versions of this License.
//
//  The Free Software Foundation may publish revised and/or new versions of
//the GNU General Public License from time to time.  Such new versions will
//be similar in spirit to the present version, but may differ in detail to
//address new problems or concerns.
//
//  Each version is given a distinguishing version number.  If the
//Program specifies that a certain numbered version of the GNU General
//Public License "or any later version" applies to it, you have the
//option of following the terms and conditions either of that numbered
//version or of any later version published by the Free Software
//Foundation.  If the Program does not specify a version number of the
//GNU General Public License, you may choose any version ever published
//by the Free Software Foundation.
//
//  If the Program specifies that a proxy can decide which future
//versions of the GNU General Public License can be used, that proxy's
//public statement of acceptance of a version permanently authorizes you
//to choose that version for the Program.
//
//  Later license versions may give you additional or different
//permissions.  However, no additional obligations are imposed on any
//author or copyright holder as a result of your choosing to follow a
//later version.
//
//  15. Disclaimer of Warranty.
//
//  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
//APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
//HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
//OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
//THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
//PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
//IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
//ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
//
//  16. Limitation of Liability.
//
//  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
//WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
//THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
//GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
//USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
//DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
//PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
//EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
//SUCH DAMAGES.
//
//  17. Interpretation of Sections 15 and 16.
//
//  If the disclaimer of warranty and limitation of liability provided
//above cannot be given local legal effect according to their terms,
//reviewing courts shall apply local law that most closely approximates
//an absolute waiver of all civil liability in connection with the
//Program, unless a warranty or assumption of liability accompanies a
//copy of the Program in return for a fee.
//
//                     END OF TERMS AND CONDITIONS
//
//            How to Apply These Terms to Your New Programs
//
//  If you develop a new program, and you want it to be of the greatest
//possible use to the public, the best way to achieve this is to make it
//free software which everyone can redistribute and change under these terms.
//
//  To do so, attach the following notices to the program.  It is safest
//to attach them to the start of each source file to most effectively
//state the exclusion of warranty; and each file should have at least
//the "copyright" line and a pointer to where the full notice is found.
//
//    <one line to give the program's name and a brief idea of what it does.>
//    Copyright (C) <year>  <name of author>
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
//Also add information on how to contact you by electronic and paper mail.
//
//  If the program does terminal interaction, make it output a short
//notice like this when it starts in an interactive mode:
//
//    <program>  Copyright (C) <year>  <name of author>
//    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
//    This is free software, and you are welcome to redistribute it
//    under certain conditions; type `show c' for details.
//
//The hypothetical commands `show w' and `show c' should show the appropriate
//parts of the General Public License.  Of course, your program's commands
//might be different; for a GUI interface, you would use an "about box".
//
//  You should also get your employer (if you work as a programmer) or school,
//if any, to sign a "copyright disclaimer" for the program, if necessary.
//For more information on this, and how to apply and follow the GNU GPL, see
//<http://www.gnu.org/licenses/>.
//
//  The GNU General Public License does not permit incorporating your program
//into proprietary programs.  If your program is a subroutine library, you
//may consider it more useful to permit linking proprietary applications with
//the library.  If this is what you want to do, use the GNU Lesser General
//Public License instead of this License.  But first, please read
//<http://www.gnu.org/philosophy/why-not-lgpl.html>.
//-------------------------------------------------------------------------------------------------
//This program, a PHP script, creates thumbnail images for recognized
//image files in the current working directory.  This program is part of a
//3-program suite designed to collectively create a web page directly from
//digital camera files (and of course the web page can be customized by
//hand-editing after it is automatically generated).  The supported process for
//creating a web page involves 3 programs (rather than 1) primarily to circumvent
//the involuntary process termination that will occur in some shared environments
//if a process consumes too much CPU time.
//
//The 3 programs in the 3-program suite are:
//
//   filenames_canonize.php:
//      Converts all names of files in a directory to lower-case, and makes
//      substitutions for any unusual characters.
//
//   thumbnails_make.php (this program):
//      Creates thumbnails from recognized image types.  The thumbnails are
//      named relative to the original image file with the suffix "_small".
//      Only 20 files are converted on each invocation of the program, to
//      avoid the involuntary process termination that typically occurs in
//      a shared hosting environment when a process uses too much CPU time.
//      The program should be run repeatedly until it indicates that it has
//      no more thumbnails to create.
//
//      If any full-sized photos are modified, any corresponding thumbnails
//      should be deleted and thumbnails_make.php and indexfile_make.php should
//      be run again.
//
//   indexfile_make.php
//      Scans a directory and makes an index file ("index2.php") displaying
//      all the thumbnail images, each of which link to the corresponding
//      full-sized image.  The index file is tailored to Dave Ashley's
//      needs, but the created file can be edited and most of the content
//      pasted into an HTML file.  To avoid the accidental loss of 
//      information, any existing "index2.php" file is renamed out of the
//      way.
//
//This script is designed to be run manually (rather than automatically invoked
//as a result of a web page request).  It was written in PHP for convenience
//simply because DreamHost (the web hosting company Dave Ashley uses) has as part
//of its hosting environment PHP with the ImageMagick library compiled in.
//
//Usually, this script is invoked using "php <path>/thumbnails_make.php", but the
//method of invocation may vary based on computing platform details.
//--------------------------------------------------------------------------------
//This program is free software: you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation, either version 3 of the License, or
//(at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU General Public License for more details.
//
//The GNU General Public License is reproduced below, and also is 
//available at http://www.gnu.org/licenses/.
//--------------------------------------------------------------------------------
//                    GNU GENERAL PUBLIC LICENSE
//                       Version 3, 29 June 2007
//
// Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
// Everyone is permitted to copy and distribute verbatim copies
// of this license document, but changing it is not allowed.
//
//                            Preamble
//
//   The GNU General Public License is a free, copyleft license for
// software and other kinds of works.
//
//   The licenses for most software and other practical works are designed
// to take away your freedom to share and change the works.  By contrast,
// the GNU General Public License is intended to guarantee your freedom to
// share and change all versions of a program--to make sure it remains free
// software for all its users.  We, the Free Software Foundation, use the
// GNU General Public License for most of our software; it applies also to
// any other work released this way by its authors.  You can apply it to
// your programs, too.
//
//   When we speak of free software, we are referring to freedom, not
// price.  Our General Public Licenses are designed to make sure that you
// have the freedom to distribute copies of free software (and charge for
// them if you wish), that you receive source code or can get it if you
// want it, that you can change the software or use pieces of it in new
// free programs, and that you know you can do these things.
//
//   To protect your rights, we need to prevent others from denying you
// these rights or asking you to surrender the rights.  Therefore, you have
// certain responsibilities if you distribute copies of the software, or if
// you modify it: responsibilities to respect the freedom of others.
//
//   For example, if you distribute copies of such a program, whether
// gratis or for a fee, you must pass on to the recipients the same
// freedoms that you received.  You must make sure that they, too, receive
// or can get the source code.  And you must show them these terms so they
// know their rights.
//
//   Developers that use the GNU GPL protect your rights with two steps:
// (1) assert copyright on the software, and (2) offer you this License
// giving you legal permission to copy, distribute and/or modify it.
//
//   For the developers' and authors' protection, the GPL clearly explains
// that there is no warranty for this free software.  For both users' and
// authors' sake, the GPL requires that modified versions be marked as
// changed, so that their problems will not be attributed erroneously to
// authors of previous versions.
//
//   Some devices are designed to deny users access to install or run
// modified versions of the software inside them, although the manufacturer
// can do so.  This is fundamentally incompatible with the aim of
// protecting users' freedom to change the software.  The systematic
// pattern of such abuse occurs in the area of products for individuals to
// use, which is precisely where it is most unacceptable.  Therefore, we
// have designed this version of the GPL to prohibit the practice for those
// products.  If such problems arise substantially in other domains, we
// stand ready to extend this provision to those domains in future versions
// of the GPL, as needed to protect the freedom of users.
//
//   Finally, every program is threatened constantly by software patents.
// States should not allow patents to restrict development and use of
// software on general-purpose computers, but in those that do, we wish to
// avoid the special danger that patents applied to a free program could
// make it effectively proprietary.  To prevent this, the GPL assures that
// patents cannot be used to render the program non-free.
//
//   The precise terms and conditions for copying, distribution and
// modification follow.
//
//                       TERMS AND CONDITIONS
//
//   0. Definitions.
//
//   "This License" refers to version 3 of the GNU General Public License.
//
//   "Copyright" also means copyright-like laws that apply to other kinds of
// works, such as semiconductor masks.
//
//   "The Program" refers to any copyrightable work licensed under this
// License.  Each licensee is addressed as "you".  "Licensees" and
// "recipients" may be individuals or organizations.
//
//   To "modify" a work means to copy from or adapt all or part of the work
// in a fashion requiring copyright permission, other than the making of an
// exact copy.  The resulting work is called a "modified version" of the
// earlier work or a work "based on" the earlier work.
//
//   A "covered work" means either the unmodified Program or a work based
// on the Program.
//
//   To "propagate" a work means to do anything with it that, without
// permission, would make you directly or secondarily liable for
// infringement under applicable copyright law, except executing it on a
// computer or modifying a private copy.  Propagation includes copying,
// distribution (with or without modification), making available to the
// public, and in some countries other activities as well.
//
//   To "convey" a work means any kind of propagation that enables other
// parties to make or receive copies.  Mere interaction with a user through
// a computer network, with no transfer of a copy, is not conveying.
//
//   An interactive user interface displays "Appropriate Legal Notices"
// to the extent that it includes a convenient and prominently visible
// feature that (1) displays an appropriate copyright notice, and (2)
// tells the user that there is no warranty for the work (except to the
// extent that warranties are provided), that licensees may convey the
// work under this License, and how to view a copy of this License.  If
// the interface presents a list of user commands or options, such as a
// menu, a prominent item in the list meets this criterion.
//
//   1. Source Code.
//
//   The "source code" for a work means the preferred form of the work
// for making modifications to it.  "Object code" means any non-source
// form of a work.
//
//   A "Standard Interface" means an interface that either is an official
// standard defined by a recognized standards body, or, in the case of
// interfaces specified for a particular programming language, one that
// is widely used among developers working in that language.
//
//   The "System Libraries" of an executable work include anything, other
// than the work as a whole, that (a) is included in the normal form of
// packaging a Major Component, but which is not part of that Major
// Component, and (b) serves only to enable use of the work with that
// Major Component, or to implement a Standard Interface for which an
// implementation is available to the public in source code form.  A
// "Major Component", in this context, means a major essential component
// (kernel, window system, and so on) of the specific operating system
// (if any) on which the executable work runs, or a compiler used to
// produce the work, or an object code interpreter used to run it.
//
//   The "Corresponding Source" for a work in object code form means all
// the source code needed to generate, install, and (for an executable
// work) run the object code and to modify the work, including scripts to
// control those activities.  However, it does not include the work's
// System Libraries, or general-purpose tools or generally available free
// programs which are used unmodified in performing those activities but
// which are not part of the work.  For example, Corresponding Source
// includes interface definition files associated with source files for
// the work, and the source code for shared libraries and dynamically
// linked subprograms that the work is specifically designed to require,
// such as by intimate data communication or control flow between those
// subprograms and other parts of the work.
//
//   The Corresponding Source need not include anything that users
// can regenerate automatically from other parts of the Corresponding
// Source.
//
//   The Corresponding Source for a work in source code form is that
// same work.
//
//   2. Basic Permissions.
//
//   All rights granted under this License are granted for the term of
// copyright on the Program, and are irrevocable provided the stated
// conditions are met.  This License explicitly affirms your unlimited
// permission to run the unmodified Program.  The output from running a
// covered work is covered by this License only if the output, given its
// content, constitutes a covered work.  This License acknowledges your
// rights of fair use or other equivalent, as provided by copyright law.
//
//   You may make, run and propagate covered works that you do not
// convey, without conditions so long as your license otherwise remains
// in force.  You may convey covered works to others for the sole purpose
// of having them make modifications exclusively for you, or provide you
// with facilities for running those works, provided that you comply with
// the terms of this License in conveying all material for which you do
// not control copyright.  Those thus making or running the covered works
// for you must do so exclusively on your behalf, under your direction
// and control, on terms that prohibit them from making any copies of
// your copyrighted material outside their relationship with you.
//
//   Conveying under any other circumstances is permitted solely under
// the conditions stated below.  Sublicensing is not allowed; section 10
// makes it unnecessary.
//
//   3. Protecting Users' Legal Rights From Anti-Circumvention Law.
//
//   No covered work shall be deemed part of an effective technological
// measure under any applicable law fulfilling obligations under article
// 11 of the WIPO copyright treaty adopted on 20 December 1996, or
// similar laws prohibiting or restricting circumvention of such
// measures.
//
//   When you convey a covered work, you waive any legal power to forbid
// circumvention of technological measures to the extent such circumvention
// is effected by exercising rights under this License with respect to
// the covered work, and you disclaim any intention to limit operation or
// modification of the work as a means of enforcing, against the work's
// users, your or third parties' legal rights to forbid circumvention of
// technological measures.
//
//   4. Conveying Verbatim Copies.
//
//   You may convey verbatim copies of the Program's source code as you
// receive it, in any medium, provided that you conspicuously and
// appropriately publish on each copy an appropriate copyright notice;
// keep intact all notices stating that this License and any
// non-permissive terms added in accord with section 7 apply to the code;
// keep intact all notices of the absence of any warranty; and give all
// recipients a copy of this License along with the Program.
//
//   You may charge any price or no price for each copy that you convey,
// and you may offer support or warranty protection for a fee.
//
//   5. Conveying Modified Source Versions.
//
//   You may convey a work based on the Program, or the modifications to
// produce it from the Program, in the form of source code under the
// terms of section 4, provided that you also meet all of these conditions:
//
//     a) The work must carry prominent notices stating that you modified
//     it, and giving a relevant date.
//
//     b) The work must carry prominent notices stating that it is
//     released under this License and any conditions added under section
//     7.  This requirement modifies the requirement in section 4 to
//     "keep intact all notices".
//
//     c) You must license the entire work, as a whole, under this
//     License to anyone who comes into possession of a copy.  This
//     License will therefore apply, along with any applicable section 7
//     additional terms, to the whole of the work, and all its parts,
//     regardless of how they are packaged.  This License gives no
//     permission to license the work in any other way, but it does not
//     invalidate such permission if you have separately received it.
//
//     d) If the work has interactive user interfaces, each must display
//     Appropriate Legal Notices; however, if the Program has interactive
//     interfaces that do not display Appropriate Legal Notices, your
//     work need not make them do so.
//
//   A compilation of a covered work with other separate and independent
// works, which are not by their nature extensions of the covered work,
// and which are not combined with it such as to form a larger program,
// in or on a volume of a storage or distribution medium, is called an
// "aggregate" if the compilation and its resulting copyright are not
// used to limit the access or legal rights of the compilation's users
// beyond what the individual works permit.  Inclusion of a covered work
// in an aggregate does not cause this License to apply to the other
// parts of the aggregate.
//
//   6. Conveying Non-Source Forms.
//
//   You may convey a covered work in object code form under the terms
// of sections 4 and 5, provided that you also convey the
// machine-readable Corresponding Source under the terms of this License,
// in one of these ways:
//
//     a) Convey the object code in, or embodied in, a physical product
//     (including a physical distribution medium), accompanied by the
//     Corresponding Source fixed on a durable physical medium
//     customarily used for software interchange.
//
//     b) Convey the object code in, or embodied in, a physical product
//     (including a physical distribution medium), accompanied by a
//     written offer, valid for at least three years and valid for as
//     long as you offer spare parts or customer support for that product
//     model, to give anyone who possesses the object code either (1) a
//     copy of the Corresponding Source for all the software in the
//     product that is covered by this License, on a durable physical
//     medium customarily used for software interchange, for a price no
//     more than your reasonable cost of physically performing this
//     conveying of source, or (2) access to copy the
//     Corresponding Source from a network server at no charge.
//
//     c) Convey individual copies of the object code with a copy of the
//     written offer to provide the Corresponding Source.  This
//     alternative is allowed only occasionally and noncommercially, and
//     only if you received the object code with such an offer, in accord
//     with subsection 6b.
//
//     d) Convey the object code by offering access from a designated
//     place (gratis or for a charge), and offer equivalent access to the
//     Corresponding Source in the same way through the same place at no
//     further charge.  You need not require recipients to copy the
//     Corresponding Source along with the object code.  If the place to
//     copy the object code is a network server, the Corresponding Source
//     may be on a different server (operated by you or a third party)
//     that supports equivalent copying facilities, provided you maintain
//     clear directions next to the object code saying where to find the
//     Corresponding Source.  Regardless of what server hosts the
//     Corresponding Source, you remain obligated to ensure that it is
//     available for as long as needed to satisfy these requirements.
//
//     e) Convey the object code using peer-to-peer transmission, provided
//     you inform other peers where the object code and Corresponding
//     Source of the work are being offered to the general public at no
//     charge under subsection 6d.
//
//   A separable portion of the object code, whose source code is excluded
// from the Corresponding Source as a System Library, need not be
// included in conveying the object code work.
//
//   A "User Product" is either (1) a "consumer product", which means any
// tangible personal property which is normally used for personal, family,
// or household purposes, or (2) anything designed or sold for incorporation
// into a dwelling.  In determining whether a product is a consumer product,
// doubtful cases shall be resolved in favor of coverage.  For a particular
// product received by a particular user, "normally used" refers to a
// typical or common use of that class of product, regardless of the status
// of the particular user or of the way in which the particular user
// actually uses, or expects or is expected to use, the product.  A product
// is a consumer product regardless of whether the product has substantial
// commercial, industrial or non-consumer uses, unless such uses represent
// the only significant mode of use of the product.
//
//   "Installation Information" for a User Product means any methods,
// procedures, authorization keys, or other information required to install
// and execute modified versions of a covered work in that User Product from
// a modified version of its Corresponding Source.  The information must
// suffice to ensure that the continued functioning of the modified object
// code is in no case prevented or interfered with solely because
// modification has been made.
//
//   If you convey an object code work under this section in, or with, or
// specifically for use in, a User Product, and the conveying occurs as
// part of a transaction in which the right of possession and use of the
// User Product is transferred to the recipient in perpetuity or for a
// fixed term (regardless of how the transaction is characterized), the
// Corresponding Source conveyed under this section must be accompanied
// by the Installation Information.  But this requirement does not apply
// if neither you nor any third party retains the ability to install
// modified object code on the User Product (for example, the work has
// been installed in ROM).
//
//   The requirement to provide Installation Information does not include a
// requirement to continue to provide support service, warranty, or updates
// for a work that has been modified or installed by the recipient, or for
// the User Product in which it has been modified or installed.  Access to a
// network may be denied when the modification itself materially and
// adversely affects the operation of the network or violates the rules and
// protocols for communication across the network.
//
//   Corresponding Source conveyed, and Installation Information provided,
// in accord with this section must be in a format that is publicly
// documented (and with an implementation available to the public in
// source code form), and must require no special password or key for
// unpacking, reading or copying.
//
//   7. Additional Terms.
//
//   "Additional permissions" are terms that supplement the terms of this
// License by making exceptions from one or more of its conditions.
// Additional permissions that are applicable to the entire Program shall
// be treated as though they were included in this License, to the extent
// that they are valid under applicable law.  If additional permissions
// apply only to part of the Program, that part may be used separately
// under those permissions, but the entire Program remains governed by
// this License without regard to the additional permissions.
//
//   When you convey a copy of a covered work, you may at your option
// remove any additional permissions from that copy, or from any part of
// it.  (Additional permissions may be written to require their own
// removal in certain cases when you modify the work.)  You may place
// additional permissions on material, added by you to a covered work,
// for which you have or can give appropriate copyright permission.
//
//   Notwithstanding any other provision of this License, for material you
// add to a covered work, you may (if authorized by the copyright holders of
// that material) supplement the terms of this License with terms:
//
//     a) Disclaiming warranty or limiting liability differently from the
//     terms of sections 15 and 16 of this License; or
//
//     b) Requiring preservation of specified reasonable legal notices or
//     author attributions in that material or in the Appropriate Legal
//     Notices displayed by works containing it; or
//
//     c) Prohibiting misrepresentation of the origin of that material, or
//     requiring that modified versions of such material be marked in
//     reasonable ways as different from the original version; or
//
//     d) Limiting the use for publicity purposes of names of licensors or
//     authors of the material; or
//
//     e) Declining to grant rights under trademark law for use of some
//     trade names, trademarks, or service marks; or
//
//     f) Requiring indemnification of licensors and authors of that
//     material by anyone who conveys the material (or modified versions of
//     it) with contractual assumptions of liability to the recipient, for
//     any liability that these contractual assumptions directly impose on
//     those licensors and authors.
//
//   All other non-permissive additional terms are considered "further
// restrictions" within the meaning of section 10.  If the Program as you
// received it, or any part of it, contains a notice stating that it is
// governed by this License along with a term that is a further
// restriction, you may remove that term.  If a license document contains
// a further restriction but permits relicensing or conveying under this
// License, you may add to a covered work material governed by the terms
// of that license document, provided that the further restriction does
// not survive such relicensing or conveying.
//
//   If you add terms to a covered work in accord with this section, you
// must place, in the relevant source files, a statement of the
// additional terms that apply to those files, or a notice indicating
// where to find the applicable terms.
//
//   Additional terms, permissive or non-permissive, may be stated in the
// form of a separately written license, or stated as exceptions;
// the above requirements apply either way.
//
//   8. Termination.
//
//   You may not propagate or modify a covered work except as expressly
// provided under this License.  Any attempt otherwise to propagate or
// modify it is void, and will automatically terminate your rights under
// this License (including any patent licenses granted under the third
// paragraph of section 11).
//
//   However, if you cease all violation of this License, then your
// license from a particular copyright holder is reinstated (a)
// provisionally, unless and until the copyright holder explicitly and
// finally terminates your license, and (b) permanently, if the copyright
// holder fails to notify you of the violation by some reasonable means
// prior to 60 days after the cessation.
//
//   Moreover, your license from a particular copyright holder is
// reinstated permanently if the copyright holder notifies you of the
// violation by some reasonable means, this is the first time you have
// received notice of violation of this License (for any work) from that
// copyright holder, and you cure the violation prior to 30 days after
// your receipt of the notice.
//
//   Termination of your rights under this section does not terminate the
// licenses of parties who have received copies or rights from you under
// this License.  If your rights have been terminated and not permanently
// reinstated, you do not qualify to receive new licenses for the same
// material under section 10.
//
//   9. Acceptance Not Required for Having Copies.
//
//   You are not required to accept this License in order to receive or
// run a copy of the Program.  Ancillary propagation of a covered work
// occurring solely as a consequence of using peer-to-peer transmission
// to receive a copy likewise does not require acceptance.  However,
// nothing other than this License grants you permission to propagate or
// modify any covered work.  These actions infringe copyright if you do
// not accept this License.  Therefore, by modifying or propagating a
// covered work, you indicate your acceptance of this License to do so.
//
//   10. Automatic Licensing of Downstream Recipients.
//
//   Each time you convey a covered work, the recipient automatically
// receives a license from the original licensors, to run, modify and
// propagate that work, subject to this License.  You are not responsible
// for enforcing compliance by third parties with this License.
//
//   An "entity transaction" is a transaction transferring control of an
// organization, or substantially all assets of one, or subdividing an
// organization, or merging organizations.  If propagation of a covered
// work results from an entity transaction, each party to that
// transaction who receives a copy of the work also receives whatever
// licenses to the work the party's predecessor in interest had or could
// give under the previous paragraph, plus a right to possession of the
// Corresponding Source of the work from the predecessor in interest, if
// the predecessor has it or can get it with reasonable efforts.
//
//   You may not impose any further restrictions on the exercise of the
// rights granted or affirmed under this License.  For example, you may
// not impose a license fee, royalty, or other charge for exercise of
// rights granted under this License, and you may not initiate litigation
// (including a cross-claim or counterclaim in a lawsuit) alleging that
// any patent claim is infringed by making, using, selling, offering for
// sale, or importing the Program or any portion of it.
//
//   11. Patents.
//
//   A "contributor" is a copyright holder who authorizes use under this
// License of the Program or a work on which the Program is based.  The
// work thus licensed is called the contributor's "contributor version".
//
//   A contributor's "essential patent claims" are all patent claims
// owned or controlled by the contributor, whether already acquired or
// hereafter acquired, that would be infringed by some manner, permitted
// by this License, of making, using, or selling its contributor version,
// but do not include claims that would be infringed only as a
// consequence of further modification of the contributor version.  For
// purposes of this definition, "control" includes the right to grant
// patent sublicenses in a manner consistent with the requirements of
// this License.
//
//   Each contributor grants you a non-exclusive, worldwide, royalty-free
// patent license under the contributor's essential patent claims, to
// make, use, sell, offer for sale, import and otherwise run, modify and
// propagate the contents of its contributor version.
//
//   In the following three paragraphs, a "patent license" is any express
// agreement or commitment, however denominated, not to enforce a patent
// (such as an express permission to practice a patent or covenant not to
// sue for patent infringement).  To "grant" such a patent license to a
// party means to make such an agreement or commitment not to enforce a
// patent against the party.
//
//   If you convey a covered work, knowingly relying on a patent license,
// and the Corresponding Source of the work is not available for anyone
// to copy, free of charge and under the terms of this License, through a
// publicly available network server or other readily accessible means,
// then you must either (1) cause the Corresponding Source to be so
// available, or (2) arrange to deprive yourself of the benefit of the
// patent license for this particular work, or (3) arrange, in a manner
// consistent with the requirements of this License, to extend the patent
// license to downstream recipients.  "Knowingly relying" means you have
// actual knowledge that, but for the patent license, your conveying the
// covered work in a country, or your recipient's use of the covered work
// in a country, would infringe one or more identifiable patents in that
// country that you have reason to believe are valid.
//
//   If, pursuant to or in connection with a single transaction or
// arrangement, you convey, or propagate by procuring conveyance of, a
// covered work, and grant a patent license to some of the parties
// receiving the covered work authorizing them to use, propagate, modify
// or convey a specific copy of the covered work, then the patent license
// you grant is automatically extended to all recipients of the covered
// work and works based on it.
//
//  A patent license is "discriminatory" if it does not include within
// the scope of its coverage, prohibits the exercise of, or is
// conditioned on the non-exercise of one or more of the rights that are
// specifically granted under this License.  You may not convey a covered
// work if you are a party to an arrangement with a third party that is
// in the business of distributing software, under which you make payment
// to the third party based on the extent of your activity of conveying
// the work, and under which the third party grants, to any of the
// parties who would receive the covered work from you, a discriminatory
// patent license (a) in connection with copies of the covered work
// conveyed by you (or copies made from those copies), or (b) primarily
// for and in connection with specific products or compilations that
// contain the covered work, unless you entered into that arrangement,
// or that patent license was granted, prior to 28 March 2007.
//
//   Nothing in this License shall be construed as excluding or limiting
// any implied license or other defenses to infringement that may
// otherwise be available to you under applicable patent law.
//
//   12. No Surrender of Others' Freedom.
//
//   If conditions are imposed on you (whether by court order, agreement or
// otherwise) that contradict the conditions of this License, they do not
// excuse you from the conditions of this License.  If you cannot convey a
// covered work so as to satisfy simultaneously your obligations under this
// License and any other pertinent obligations, then as a consequence you may
// not convey it at all.  For example, if you agree to terms that obligate you
// to collect a royalty for further conveying from those to whom you convey
// the Program, the only way you could satisfy both those terms and this
// License would be to refrain entirely from conveying the Program.
//
//   13. Use with the GNU Affero General Public License.
//
//   Notwithstanding any other provision of this License, you have
// permission to link or combine any covered work with a work licensed
// under version 3 of the GNU Affero General Public License into a single
// combined work, and to convey the resulting work.  The terms of this
// License will continue to apply to the part which is the covered work,
// but the special requirements of the GNU Affero General Public License,
// section 13, concerning interaction through a network will apply to the
// combination as such.
//
//   14. Revised Versions of this License.
//
//   The Free Software Foundation may publish revised and/or new versions of
// the GNU General Public License from time to time.  Such new versions will
// be similar in spirit to the present version, but may differ in detail to
// address new problems or concerns.
//
//   Each version is given a distinguishing version number.  If the
// Program specifies that a certain numbered version of the GNU General
// Public License "or any later version" applies to it, you have the
// option of following the terms and conditions either of that numbered
// version or of any later version published by the Free Software
// Foundation.  If the Program does not specify a version number of the
// GNU General Public License, you may choose any version ever published
// by the Free Software Foundation.
//
//   If the Program specifies that a proxy can decide which future
// versions of the GNU General Public License can be used, that proxy's
// public statement of acceptance of a version permanently authorizes you
// to choose that version for the Program.
//
//   Later license versions may give you additional or different
// permissions.  However, no additional obligations are imposed on any
// author or copyright holder as a result of your choosing to follow a
// later version.
//
//   15. Disclaimer of Warranty.
//
//   THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
// APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
// HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
// IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
// ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
//
//   16. Limitation of Liability.
//
//   IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
// WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
// THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
// GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
// USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
// DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
// PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
// EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGES.
//
//   17. Interpretation of Sections 15 and 16.
//
//   If the disclaimer of warranty and limitation of liability provided
// above cannot be given local legal effect according to their terms,
// reviewing courts shall apply local law that most closely approximates
// an absolute waiver of all civil liability in connection with the
// Program, unless a warranty or assumption of liability accompanies a
// copy of the Program in return for a fee.
//--------------------------------------------------------------------------------
//C O N F I G U R A T I O N
//--------------------------------------------------------------------------------
//Configuration switch combinations were not tested.  E-mail me any program
//corrections (dashley@gmail.com).
define ("CFG_PROGNAME", "thumbnails_make.php");
   //Number of characters per line preferred for console output.
define ("CFG_CONSOLE_STD_LINE_LEN", 78);
   //Number of characters per line preferred for console output.
define ("CFG_THUMBNAIL_DIMENSION_MAX", 125);
   //The maximum dimension of the created thumbnails.  Thumbnails are sized so
   //that the longest dimension is this many pixels.
define ("CFG_THUMBNAIL_BEVELED_BORDER_WIDTH", 4);
   //The number of pixels that the thumbnail beveled borders should be.
define ("CFG_THUMBNAIL_FILENAME_SUFFIX", "_small");
   //String added just before the filename extension to choose thumbnail names
   //based on name of full-sized image.
define ("CFG_LANCZOS_FILTER_APPLY", FALSE);
   //TRUE if should apply the Lanczos filter when making the thumbnail, FALSE
   //otherwise.  I have no idea if using a Lanczos filter improves the quality
   //of the thumbnails, but the filter was applied in the PHP example I found
   //online.  Applying the Lanczos filter typically adds a few seconds to the
   //time required to create each thumbnail.
define ("CFG_MAX_THUMBNAILS_PER_INVOCATION", 20);
   //The maximum number of thumbnails that should be created per invocation.
   //This is to prevent the program from being involuntarily terminated
   //for taking too much CPU time.
//--------------------------------------------------------------------------------
//Calculates important integer indices related to creating a thumbnail, in order
//to minimize distortion in the thumbnail.
//
//When creating a thumbnail, the longer side may be relatively short (perhaps
//100 pixels), and the shorter side may be even shorter (perhaps even as short
//as 10 pixels).  If the dimensions of the original image were not changed,
//converting the image to a thumbnail may result in distortion of up to about
//one percent.  As an example, suppose that a 1600 x 900 image is converted to a
//thumbnail with the longer side of 125 pixels.  The ideal dimension for the
//shorter side would be (900/1600) * 125 = 70.3125 pixels.  The aspect ratio of
//the thumbnail can't be made to match the aspect ratio of the original image.
//
//To avoid any aspect ratio distortion that might be noticeable, this program
//chooses the shorter dimension for the thumbnail that is the ceiling of the actual
//quotient, then crops the longer dimension of the original image before the
//conversion to try and match the aspect ratios as closely as possible.
//
//In the example a paragraph or two above, the shorter side of the thumbnail
//would be chosen to be 71 pixels.
//
//Once this choice is made, we want to trim the original image before conversion
//so that n/900 is as close as possible to 125/71.  n = (900 * 125) / 71 = 
//1584.5070 pixels, so we choose 1585.  This keeps the aspect ratio of the 
//original image and the thumbnail as close as possible.
//
//Although the longer side of the original image may be reduced prior to the
//conversion to a thumbnail, this information is not written to disk, and
//the original image is not modified.  The adjustment of the longer side is
//just a conversion trick to hopefully get better thumbnails. 
function calc_thumbnail_conversion_pars
         (
           $in_orig_longer,
              //Longer dimension of original image.
           $in_orig_shorter,
              //Shorter dimension of original image.
           $in_thumbnail_longer,
              //Longer dimension of desired thumbnail.
         & $out_thumbnail_longer,
              //Longer dimension of thumbnail that should be created.
         & $out_thumbnail_shorter,
              //Shorter dimension of thumbnail that should be created.
         & $out_orig_crop_dim_longer,
              //The size to crop to on the longer axis of the original.
         & $out_orig_crop_dim_shorter,
              //The size to crop to on the shorter axis of the original.
         & $out_orig_crop_start_longer,
              //For use with the Imagick:cropImage() method, the start
              //position of the crop on the longer axis.
         & $out_orig_crop_start_shorter
              //For use with the Imagick:cropImage() method, the start
              //position of the crop on the shorter axis.
         )
{
   //Set the thumbnail shorter dimension to the floor.  This means would need to trim
   //longest dimension of original to match aspect ratio as closely as possible.
   $out_thumbnail_longer        = $in_thumbnail_longer;
   $out_thumbnail_shorter       = ceil(((float)$in_thumbnail_longer * 
                                  (float)$in_orig_shorter) / (float)$in_orig_longer);
   settype($out_thumbnail_shorter, "integer");

   //The aspect ratio of the thumbnail is now set.  Try to match the aspect ratio of the larger
   //image as closely as possible by selecting a smaller number for the long axis of the
   //original image.
   $out_orig_crop_dim_longer = round(((float)$in_thumbnail_longer * 
                               (float)$in_orig_shorter) / (float)$out_thumbnail_shorter);
   settype($out_orig_crop_dim_longer, "integer");

   //The original keeps its shorter dimension unchanged.
   $out_orig_crop_dim_shorter   = $in_orig_shorter;

   //Set the cropping of the longer side of the original to cover half the necessary
   //reduction.
   $out_orig_crop_start_longer  = round(((float)$in_orig_longer - 
                                  (float)$out_orig_crop_dim_longer) / 2.0);
   settype($out_orig_crop_start_longer, "integer");

   //No cropping of original shorter side.
   $out_orig_crop_start_shorter = 0;
}
//--------------------------------------------------------------------------------
//Repeats a character to the console output a certain number of times.
function rep_char_con($c, $n)
{
   while ($n--)
      echo $c;
}
//--------------------------------------------------------------------------------
//Writes a standard thick horizontal line to the console.
function hor_line_thick()
{
   rep_char_con("=", CFG_CONSOLE_STD_LINE_LEN);
   echo "\n";
}
//--------------------------------------------------------------------------------
//Writes a standard thin horizontal line to the console.
function hor_line_thin()
{
   rep_char_con("-", CFG_CONSOLE_STD_LINE_LEN);
   echo "\n";
}
//--------------------------------------------------------------------------------
//Returns an array of all files in the working directory.
//If no files can be found, returns FALSE.
function get_file_names_in_dir()
{
   //Get directory list.
   $rv = scandir (".");

   //If the list is empty, something went wrong.  Return FALSE.
   if ($rv === FALSE)
      return FALSE;

   return $rv;
}
//--------------------------------------------------------------------------------
//Returns TRUE if a file name appears to be a valid full-sized image name, 
//or FALSE otherwise.
function is_full_sized_image_file_name($in_filename)
{
   //Convert the string name to all lower case.  This will do for
   //comparisons and tests.
   $s = strtolower($s);

   //Attempt to split the name into a base and an extension.  Any failure
   //means it is an unsuitable name.
   $extension_start = strrpos($in_filename, ".");
      //Find position of last "." in string.  This should precede the
      //file extension.

   if ($extension_start === FALSE)
   {
      //Bad name.  Unsuitable.
      return FALSE;
   } 

   //Calculate the base and extension.
   $filename_base    = substr($in_filename, 0, $extension_start);
   $filename_extension = substr($in_filename, $extension_start + 1);

   //If the extension is neither "jpg" nor "jpeg", it is unsuitable.
   if (($filename_extension != "jpg") && ($filename_extension != "jpeg"))
      return FALSE;

   //If the filename base is empty, the filename is unsuitable.
   if (strlen($filename_base) == 0)
      return FALSE;

   //If the last characters of the base are the CFG_THUMBNAIL_FILENAME_SUFFIX,
   //the name is unsuitable.
   if (strlen($filename_base) >= strlen(CFG_THUMBNAIL_FILENAME_SUFFIX))
   {
      if (substr($filename_base, strlen($filename_base) - strlen(CFG_THUMBNAIL_FILENAME_SUFFIX)) 
          == CFG_THUMBNAIL_FILENAME_SUFFIX)
         return FALSE;
   }

   //Looks good.
   return TRUE;
}
//--------------------------------------------------------------------------------
//As a function of the file name, creates the file name for the thumbnail.
function file_name_to_thumbnail_name($in_filename)
{
   $extension_start = strrpos($in_filename, ".");
      //Find position of last "." in string.  This should precede the
      //file extension.
   if ($extension_start === FALSE)
   {
      //"." not found.  Should not happen.  Filenames were checked in advance.
      echo "Fatal internal error at line " . __LINE__ . "\n";
      exit(1);
   } 

   $filename_prefix    = substr($in_filename, 0, $extension_start);
   $filename_extension = substr($in_filename, $extension_start);

   $rv = $filename_prefix . CFG_THUMBNAIL_FILENAME_SUFFIX . $filename_extension;

   return $rv;
}
//--------------------------------------------------------------------------------
//Actually creates the thumbnail, and returns some information about what was
//done.
//
//The calls to the ImagMagick library take on the order of 5s per image if there
//is filtering.
function create_thumbnail(  $in_filename, 
                            $in_thumbnailname,
                          & $out_filename_filesize,
                          & $out_filename_xdim,
                          & $out_filename_ydim,
                          & $out_thumbnailname_filesize,
                          & $out_thumbnailname_xdim,
                          & $out_thumbnailname_ydim)
{
   //Assign output parameters just in case something doesn't get assigned.
   $out_filename_filesize      = 0;
   $out_filename_xdim          = 0;
   $out_filename_ydim          = 0;
   $out_thumbnailname_filesize = 0;
   $out_thumbnailname_xdim     = 0;
   $out_thumbnailname_ydim     = 0;

   //Establish target dimensions.  Two cases, depending on which is the longer
   //side.

   //Construct.
   $imagick = new Imagick();

   //Load image.
   $imagick->readImage($in_filename);

   //Get the dimensions of the image we just loaded.
   $geo               = $imagick->getImageGeometry(); 
   $out_filename_xdim = $geo['width']; 
   $out_filename_ydim = $geo['height']; 

   //Calculate target sizes.  We rearrange parameters based on which is our
   //longest side.
   if ($out_filename_xdim >= $out_filename_ydim)
   {
      //Longer width (x-dimension), or square.
      calc_thumbnail_conversion_pars
         (
         $out_filename_xdim,
         $out_filename_ydim,
         CFG_THUMBNAIL_DIMENSION_MAX,
         $out_thumbnailname_xdim,
         $out_thumbnailname_ydim,
         $orig_crop_dim_x,
         $orig_crop_dim_y,
         $orig_crop_start_x,
         $orig_crop_start_y
         );
   }
   else
   {
      //Longer height (y-dimension).
      calc_thumbnail_conversion_pars
         (
         $out_filename_ydim,
         $out_filename_xdim,
         CFG_THUMBNAIL_DIMENSION_MAX,
         $out_thumbnailname_ydim,
         $out_thumbnailname_xdim,
         $orig_crop_dim_y,
         $orig_crop_dim_x,
         $orig_crop_start_y,
         $orig_crop_start_x
         );
   }

   //For debugging only, might want to know intermediate calculation results.
   //echo "xcropdim, ycropdim, xcropstart, ycropstart: "
   //     .
   //     $orig_crop_dim_x
   //     .
   //     " "
   //     . 
   //     $orig_crop_dim_y
   //     .
   //     " "
   //     . 
   //     $orig_crop_start_x
   //     .
   //     " "
   //     . 
   //     $orig_crop_start_y
   //     .
   //     "\n";
           
   //Crop the original to try to preserve the aspect ratio of the thumbnail
   //as precisely as possible.
   $imagick->cropImage( 
                      $orig_crop_dim_x, 
                      $orig_crop_dim_y,
                      $orig_crop_start_x,
                      $orig_crop_start_y
                      );

   //For debugging only, might want to get a look at the cropped image, to
   //be sure nothing unexpected happens on the canvas.
   //$imagick->writeImage($in_filename . ".cropped.jpg");

   //Resize to thumbnail size.
   if (CFG_LANCZOS_FILTER_APPLY)
   {
      $imagick->resizeImage($out_thumbnailname_xdim, 
                            $out_thumbnailname_ydim, 
                            Imagick::FILTER_LANCZOS, 
                            1);
   }
   else
   {
      $imagick->resizeImage($out_thumbnailname_xdim, 
                            $out_thumbnailname_ydim, 
                            0, 
                            1);
   }

   //Create the border.
   $imagick->raiseImage(CFG_THUMBNAIL_BEVELED_BORDER_WIDTH, 
                        CFG_THUMBNAIL_BEVELED_BORDER_WIDTH, 
                        0, 
                        0, 
                        1);

   //Set compression to get a smaller thumbnail written, and strip
   //header information.  stripImage() seems to have the largest effect
   //on thumbnail file size, so leaving the thumbnail quality near 100%
   //is feasible.  The jump in file size between 90% and 95% seemed to be
   //fairly large (40% to 50%), so I left it at 90%.  My rationale is
   //that with the proliferation of mobile devices and cellular data,
   //getting the thumbnail as small as possible is more important than
   //the thumbnail looking perfect.  If the viewer wants a perfect image,
   //they can view the full-sized image.
   $imagick->setImageCompression(Imagick::COMPRESSION_JPEG); 
   $imagick->setImageCompressionQuality(90);
   $imagick->stripImage(); 

   //Write the thumbnail.
   $imagick->writeImage($in_thumbnailname);

   //Destroy to prevent memory leak.
   $imagick->clear(); 
   $imagick->destroy(); 

   //All of the writing is done.  Try to obtain the file sizes.
   $fsize = filesize($in_filename);
   if ($fsize !== FALSE)
      $out_filename_filesize = $fsize;
   $fsize = filesize($in_thumbnailname);
   if ($fsize !== FALSE)
      $out_thumbnailname_filesize = $fsize;
}
//--------------------------------------------------------------------------------
   //Write introductory message.
   hor_line_thick();
   echo CFG_PROGNAME . " Copyright (C) 2015 David T. Ashley\n";
   echo "This program comes with ABSOLUTELY NO WARRANTY; and is licensed under\n";
   echo "the GNU General Public License, Version 3.  A copy of this license is\n";
   echo "provided in the source code of this program.\n";
   hor_line_thin();
   //-----------------------------------------------------------------------------
   //Get and emit the names of everything in the directory.
   $file_list = get_file_names_in_dir();
   if ($file_list === FALSE)
   {
      echo "List of files from PHP function scandir() is empty.\n";
      echo "Serious internal error, or nothing to do.  Script cannot continue.\n";
      hor_line_thick();
      exit(1);
   }
   else
   {
     echo "Files in working directory (unsorted, unfiltered, " 
          . 
          count($file_list)
          . 
          " files):\n";
     for ($i = 0; $i < count($file_list); $i++)
        echo "   " . sprintf("[%5d]", $i) . " " . $file_list[$i] . "\n";
   }
   hor_line_thin();
   //-----------------------------------------------------------------------------
   //Remove the standard directory entries "." and ".." from the list, and 
   //remove any directories.
   $temp_list = $file_list;
   unset($file_list);
   $n = 0;
   for ($i = 0; $i < count($temp_list); $i++)
   {
      //echo "Checking " . $temp_list[$i] . "\n";

      if (strcmp($temp_list[$i], ".") == 0)
      {
         //. entry, not a file.
      }
      else if (strcmp($temp_list[$i], "..") == 0)
      {
         //.. entry, not a file.
      }
      else if (is_file($temp_list[$i]))
      {
         //This is a regular file.
         $file_list[] = $temp_list[$i];
         $n++;
      }
   }
   
   if ($n == 0)
      $file_list = FALSE;

   unset($n);
   unset($temp_list);
   //-----------------------------------------------------------------------------
   //If there is nothing to do, end the script.
   if ($file_list === FALSE)
   {
      echo "No files to process.\n";
      hor_line_thick();
      exit(0);
   }
   //-----------------------------------------------------------------------------
   //Sort the list.  This is a non-event.  The only rationale for sorting is that
   //it ensures that the same set of files will be processed in the same order,
   //regardless of the order provided by the underlying OS internals.
   sort($file_list);
   //-----------------------------------------------------------------------------
   //Emit the names we now have.
   echo "Files in working directory (directory entries removed, sorted, " 
        . 
        count($file_list)
        . 
        " files):\n";
   for ($i = 0; $i < count($file_list); $i++)
      echo "   " . sprintf("[%5d]", $i) . " " . $file_list[$i] . "\n";
   hor_line_thin();

   //-----------------------------------------------------------------------------
   //For each file that is appropriate and where the thumbnail does not already
   //exist, up to the maximum we may do in one invocation, create the thumbnail.
   $i         = 0;
   $completed = 0;
   while (($completed < CFG_MAX_THUMBNAILS_PER_INVOCATION) && ($i < count($file_list)))
   {
      if (is_full_sized_image_file_name($file_list[$i]))
      {
         $thumbnail_name = file_name_to_thumbnail_name($file_list[$i]);

         if (file_exists($thumbnail_name))
         {
            echo "   " . sprintf("[%5d]", $i) . " " . $file_list[$i] . " : skipping because corresponding thumbnail exists.\n";
            hor_line_thin();
         }
         else
         {
            echo "   " . sprintf("[%5d]", $i) . " " . $file_list[$i] . " : creating thumbnail.\n";

            echo "Creating thumbnail \"" .
                 $thumbnail_name .
                 "\" from image \"" .
                 $file_list[$i] .
                 "\".\n";

            create_thumbnail($file_list[$i], 
                             $thumbnail_name,
                             $filename_filesize,
                             $filename_xdim,
                             $filename_ydim,
                             $thumbnail_filesize,
                             $thumbnail_xdim,
                             $thumbnail_ydim);

            echo "Conversion complete.\n";
            echo "   Full-sized image file size/xdim/ydim = " .
                 $filename_filesize . "/" . $filename_xdim . "/" . $filename_ydim .
                 ",\n";
            echo "   Thumbnail image  filesize/xdim/ydim = " .
                 $thumbnail_filesize . "/" . $thumbnail_xdim . "/" . $thumbnail_ydim .
                 ",\n";

            hor_line_thin();
            $completed++;
         }
      }
      else
      {
         //Unsuitable base name.  Can't use it.
         echo "   " . sprintf("[%5d]", $i) . " " . $file_list[$i] . " : skipping due to unsuitable name.\n";
         hor_line_thin();
      }

      $i++;
   }

   //Emit a message about whether the program should be run again.  I am aware of
   //the uncovered case--where the last thumbnail was made on the last iteration
   //of this invocation--but I will leave it uncovered for now.  All that happens
   //is the user runs the program unnecessarily one more time.
   if ($completed == 0)
   {
      echo "No thumbnails were created--this program is done creating thumbnails.\n";
      echo "It is not necessary to run this program again.\n";
      hor_line_thin();
   }
   else
   {
      echo $completed . " thumbnail(s) were created.  Please run this program repeatedly again\n";
      echo "until no more thumbnails are created.\n";
      hor_line_thin();
   }

   echo CFG_PROGNAME . " execution ends.\n";
   hor_line_thick();
//--------------------------------------------------------------------------------
//End of File
//--------------------------------------------------------------------------------
?>