+++
date = "2017-03-01T17:08:52+02:00"
author = "Alan Orth"
title = "March, 2017"
tags = ["Notes"]

+++
## 2017-03-01

- Run the 279 CIAT author corrections on CGSpace

## 2017-03-02

- Filed an issue on DSpace issue tracker for the `filter-media` bug that causes it to process JPGs even when limiting to the PDF thumbnail plugin: [DS-3516](https://jira.duraspace.org/browse/DS-3516)
- Discovered that the ImageMagic `filter-media` plugin creates JPG thumbnails with the CMYK colorspace when the source PDF is using CMYK
- Interestingly, it seems DSpace 4.x's thumbnails were sRGB, but forcing regeneration using DSpace 5.x's ImageMagick plugin creates CMYK JPGs if the source PDF was CMYK (see [10568/51999](https://cgspace.cgiar.org/handle/10568/51999)):

```
$ identify ~/Desktop/alc_contrastes_desafios.jpg
/Users/aorth/Desktop/alc_contrastes_desafios.jpg JPEG 464x600 464x600+0+0 8-bit CMYK 168KB 0.000u 0:00.000
```

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- 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
```