On Sun, Oct 12, 2014 at 8:41 AM, Elle Stone <ellestone@xxxxxxxxxxxxxxxxxxxx> wrote: > On 10/11/2014 08:52 PM, Jon Nordby wrote: > Please correct me if I misunderstood what you are saying. I think you are > saying: > > GIMP uses GTK+. > > GTK+ uses Cairo APIs for rendering to the screen. > > Cairo APIs assume 8-bit sRGB. > > Therefore in GTK+ applications such as GIMP, images must be converted to > sRGB before they can be displayed on the screen. The same applies for most UI toolkits/APIs integrating with color management; the implementation that is unmanaged (or all!) content is to be presented in the framebuffer as sRGB and the desktop color management to compensate towards the monitor profile. Applications like GIMP, image viewers and similar - should be requesting that rectangular parts of the UI (image viewing areas and similar) be excepted from these conversions. Ideally we would be dealing differently with, no desktop CM and no display profile, no desktop CM (but have a display profile), desktop CMM without ability to opt out regions, and desktop CM with the ability to opt out regions. sRGB goes even deeper in cairo, where all API entry points where individual colors are specified for stroking/filling/gradients is specified as floating point sRGB (with the TRC as well). Buffers we get from cairo for doing things like text rendering are 8bit sRGBA with sRGB TRC and pre-multiplied alpha. An annoyance for GEGL is that cairo is limited to 8bpc in its rasterization of vectors (by using a clever implementation choice; which makes things fast - but tricky to adapt for >8bit.). Cairo is just one part of our eco-system which is following the guidelines of how to integrate with color management even if you do it badly; assume sRGB. Mostly everyone else tries to assume sRGB for consistency - when color management is considered hard; babl aims to make it easy and fast for GEGL to continue integrating with such code. /pippin (btw, babl/docs/roadmap.txt has been slightly updated). _______________________________________________ gimp-developer-list mailing list List address: gimp-developer-list@xxxxxxxxx List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
