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POTest suite for GIF containing images using rarely used features
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  1. POTest suite for GIF containing images using rarely used features
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    copied!<p>The specifications (plural, since there are versions 87a and 89a) of the GIF graphics format are easy to find in the internet (for those who don't want to google:</p> <ul> <li><a href="http://www.w3.org/Graphics/GIF/spec-gif87.txt" rel="noreferrer">http://www.w3.org/Graphics/GIF/spec-gif87.txt</a></li> <li><a href="http://www.w3.org/Graphics/GIF/spec-gif89a.txt" rel="noreferrer">http://www.w3.org/Graphics/GIF/spec-gif89a.txt</a>)</li> </ul> <p>As you can see in the specification GIF has support for some features that I have never seen used; I only want to give two examples (for simplicity from GIF 89a): - Plaintext extension: on <a href="http://www.vias.org/pngguide/chapter11_15.html" rel="noreferrer">http://www.vias.org/pngguide/chapter11_15.html</a> there is a little bit more detailed documentation - Pixel Aspect Ratio: see section 18. Logical Screen Descriptor. of GIF 89a specification</p> <p>On the other hand, for PNG there seem to be lots of test images available: <a href="http://www.libpng.org/pub/png/pngmisc.html" rel="noreferrer">http://www.libpng.org/pub/png/pngmisc.html</a> (scroll down); the most common one is the official PNG test suite <a href="http://www.schaik.com/pngsuite/" rel="noreferrer">http://www.schaik.com/pngsuite/</a> that is also mirrored at <a href="http://www.libpng.org/pub/png/pngsuite.html" rel="noreferrer">http://www.libpng.org/pub/png/pngsuite.html</a>.</p> <p>What I am looking for is a test suite of GIF images that also/especially contains images using features that are rarely used or often implemented in a wrong way.</p> <p>The best results that I could find in the internet are the following:</p> <ul> <li>Images linked from <a href="http://en.wikipedia.org/w/index.php?title=Graphics_Interchange_Format" rel="noreferrer">http://en.wikipedia.org/w/index.php?title=Graphics_Interchange_Format</a> - among them images using some not-so common GIF features</li> <li><a href="http://phil.ipal.org/tc217.gif" rel="noreferrer">http://phil.ipal.org/tc217.gif</a> (as an example how to use 24 bit depth in GIF files) - linked from <a href="http://phil.ipal.org/tc.html" rel="noreferrer">http://phil.ipal.org/tc.html</a> and referenced in <a href="http://en.wikipedia.org/w/index.php?title=Graphics_Interchange_Format&amp;oldid=411332804#cite_note-8" rel="noreferrer">http://en.wikipedia.org/w/index.php?title=Graphics_Interchange_Format&amp;oldid=411332804#cite_note-8</a>)</li> <li>The file <a href="http://www-eng-x.llnl.gov/documents/a_image.gif" rel="noreferrer">http://www-eng-x.llnl.gov/documents/a_image.gif</a> (referenced in <a href="http://www-eng-x.llnl.gov/documents/tests/gif.html" rel="noreferrer">http://www-eng-x.llnl.gov/documents/tests/gif.html</a>) claims this to be a test image; for me it rather looks like it is from a time when GIF support was not common in browsers</li> <li>Under <a href="http://www.fileformat.info/format/gif/sample/index.htm" rel="noreferrer">http://www.fileformat.info/format/gif/sample/index.htm</a> there are files called "GIF Sample Files"; it doesn't look to me that they use more than the "very common" features of GIF</li> </ul> <p>So I could find nothing fullfilling the above stated criterion of a test suite of GIF images also/especially containing features that are rarely used or often implemented in a wrong way.</p> <p>So: do you know of such a test suite?</p>
 

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