Fyi... I last looked at both GraphicsMagick and ImageMagick in 2013 when I was writing a custom batch image converter. Because GraphicsMagick had a reputation for better performance[1] I initially wrote my wrapper tool around GraphicsMagick. However, I encountered bugs with Photoshop PSD files (e.g. not properly reading multi-layer PSD files.[2]) That's when I found out that ImageMagick tracks the PSD file format more reliably than GraphicsMagick. Yes, GM later fixed that particular bug in 2014 but I had already revised my tool to use IM.
Lesson learned: if processing PSD files is critical to your project, you'll want to favor ImageMagick over GraphicsMagick. The author of GM admits the parser of PSD is not the best so it's something to keep in mind.
Lesson learned: if processing PSD files is critical to your project, you'll want to favor ImageMagick over GraphicsMagick. The author of GM admits the parser of PSD is not the best so it's something to keep in mind.
[1]Flickr and Etsy used GM on their backends:
http://www.slideshare.net/jallspaw/operational-efficiency-ha...
http://www.web2expo.com/webexsf2009/public/schedule/detail/8...
[2]https://sourceforge.net/p/graphicsmagick/bugs/242/
[3]also some bonus links on why PSD is very difficult to parse correctly:
https://github.com/gco/xee/blob/master/XeePhotoshopLoader.m?...
http://blogs.adobe.com/jnack/2009/05/some_thoughts_about_the...