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Update notes for 2017-03-03

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Alan Orth
2017-03-03 18:40:38 +02:00
parent 644e443069
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@ -82,7 +82,7 @@ $ identify ~/Desktop/alc_contrastes_desafios.jpg
"headline": "March, 2017",
"url": "https://alanorth.github.io/cgspace-notes/2017-03/",
"wordCount": "113",
"wordCount": "218",
"datePublished": "2017-03-01T17:08:52+02:00",
@ -178,7 +178,7 @@ $ identify ~/Desktop/alc_contrastes_desafios.jpg
<p></p>
<ul>
<li>This results in discolored thumbnails, sRGB and CMYK:</li>
<li>This results in discolored thumbnails when compared to the original PDF, for example sRGB and CMYK:</li>
</ul>
<p><img src="/cgspace-notes/2017/03/thumbnail-srgb.jpg" alt="Thumbnail in sRGB colorspace" /></p>
@ -189,6 +189,28 @@ $ identify ~/Desktop/alc_contrastes_desafios.jpg
<li>I filed an issue for the color space thing: <a href="https://jira.duraspace.org/browse/DS-3517">DS-3517</a></li>
</ul>
<h2 id="2017-03-03">2017-03-03</h2>
<ul>
<li>I created a patch for DS-3517 and made a pull request against upstream <code>dspace-5_x</code>: <a href="https://github.com/DSpace/DSpace/pull/1669">https://github.com/DSpace/DSpace/pull/1669</a></li>
<li>Looks like <code>-colorspace sRGB</code> alone isn&rsquo;t enough, we need to use profiles:</li>
</ul>
<pre><code>$ convert -thumbnail 300x300 -flatten -profile /opt/brew/Cellar/ghostscript/9.20/share/ghostscript/9.20/iccprofiles/default_cmyk.icc -profile /opt/brew/Cellar/ghostscript/9.20/share/ghostscript/9.20/iccprofiles/default_rgb.icc alc_contrastes_desafios.pdf\[0\] alc_contrastes_desafios.pdf.jpg
</code></pre>
<ul>
<li>This is a great resource describing the color stuff: <a href="http://www.imagemagick.org/Usage/formats/#profiles">http://www.imagemagick.org/Usage/formats/#profiles</a></li>
<li>Somehow we need to detect the color system being used by the input file and handle each case differently</li>
<li>This is trivial with <code>identify</code> (even by the <a href="http://im4java.sourceforge.net/api/org/im4java/core/IMOps.html#identify">Java ImageMagick API</a>):</li>
</ul>
<pre><code>$ identify -format '%r\n' alc_contrastes_desafios.pdf\[0\]
DirectClass CMYK
$ identify -format '%r\n' Africa\ group\ of\ negotiators.pdf\[0\]
DirectClass sRGB Alpha
</code></pre>