Update notes for 2017-03-03

content/post/2017-03.md

@@ -22,10 +22,30 @@ $ identify ~/Desktop/alc_contrastes_desafios.jpg
 
 <!--more-->
 
-- This results in discolored thumbnails, sRGB and CMYK:
+- This results in discolored thumbnails when compared to the original PDF, for example sRGB and CMYK:
 
 ![Thumbnail in sRGB colorspace](/cgspace-notes/2017/03/thumbnail-srgb.jpg)
 
 ![Thumbnial in CMYK colorspace](/cgspace-notes/2017/03/thumbnail-cmyk.jpg)
 
 - I filed an issue for the color space thing: [DS-3517](https://jira.duraspace.org/browse/DS-3517)
+
+## 2017-03-03
+
+- I created a patch for DS-3517 and made a pull request against upstream `dspace-5_x`: https://github.com/DSpace/DSpace/pull/1669
+- Looks like `-colorspace sRGB` alone isn't enough, we need to use profiles:
+
+```
+$ 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
+```
+
+- This is a great resource describing the color stuff: http://www.imagemagick.org/Usage/formats/#profiles
+- Somehow we need to detect the color system being used by the input file and handle each case differently
+- This is trivial with `identify` (even by the [Java ImageMagick API](http://im4java.sourceforge.net/api/org/im4java/core/IMOps.html#identify)):
+
+```
+$ identify -format '%r\n' alc_contrastes_desafios.pdf\[0\]
+DirectClass CMYK
+$ identify -format '%r\n' Africa\ group\ of\ negotiators.pdf\[0\]
+DirectClass sRGB Alpha
+```