Until recently, the issues with FOSS and photo post processing was loss of data while RAW conversion, poor colour management, lack of 16 bit support etc.
Finally it seems Gimp 2.9 is addressing the 16 – bit issue which was until recently addressed only by CinePaint. Yes there are multitude of options like Photivo, Krita etc but IMHO if all these efforts are combined in building a better GIMP, RAW support etc things could have been better. Looks like too much of a freedom is not always the right way unless there is a guiding force.
Gimp 2.9 30 May 2013 development branch with a unified / single window, support for images with upto 32 bit floating point precision (hurray!!), better colour profile management – trust me! my TIFF images looks the same in Mac OS X & GNU/Linux now, GEGL
Here I am trying to get Gimp 2.9 working on GNU/Linux flavours and if possible on Mac OS X as well & explaining photo processing with Gimp 2.9. I am thinking of using RawTherapee (http://rawtherapee.com/) for RAW conversion as I am not happy with UFRaw. For the colour management I am using Open-ICC profiles, Argyll CMS & UI
- Photos are taken in Adobe RGB 1998
- Monitor uses calibrated profile
- Processing is done with ProPhoto profile from OpenICC bundle
- RAWTherapee is used for RAW conversion
- Final output in JPEG and TIFF are saved with Adobe RGB 1998
- Gimp 2.9 compiled from source is used as it supports 16 – bit image formats
- RAM is used for GEGEL swap for faster performance by mounting tmpfs with 6GB (instead of default 50% physical memory size)
- Linux SWAP is also getting used upto 2.8 GB
Setting the stage
The first step is to install OpenICC profiles
Compile Gimp 2.9 as per the instructions
Install RAW therapee & get an image ready.
Errors & fixes:
The first error I came across was babl accessing a different process and can be fixed with a less “secure” kernel setting as shown below.
Change ptrace_scop by Editing /etc/sysctl.d/10-ptrace.conf & the resultant value should be: kernel.yama.ptrace_scope = 0
Keel in mind that this will be applicable only after restart & we can change proc values as follows.
# echo 0 > /proc/sys/kernel/yama/ptrace_scope
Yet to find a solution for this.
(script-fu:1976): LibGimpBase-WARNING **: script-fu: gimp_wire_read(): error
I will be updating the document with more insights and automation. For now, the above steps should work and may be you want to look into some GIMP tutorials like: http://blog.patdavid.net/2013/03/the-open-source-portrait-postprocessing.html