On Mon, Apr 21, 2014 at 2:55 AM, Gez <listas@xxxxxxxxxxxx> wrote: > El dom, 20-04-2014 a las 17:03 +0200, Øyvind Kolås escribió: >> the sRGB chromaticities; or CIE Lab, or any other babl defined format. >> With a potential future babl lcms2 extension; the original pixels >> could even be kept in the layers raster storage.. doing so would have >> no effect on display of the pixels or processing of them since things >> are converted _on_demand_ to the pixel formats requested by the >> operations. Doing this would for the user not be functionally >> different in any way; apart from a risk of things being slower. > > Exactly how much work is required to create transforms from any other > colorspace to the existing babl pixel formats? > Is sRGB hardcoded in all the operations that flip pixel formats or it > can be replaced without having to re-write all of them? > > I mean, would it be possible to create different "profiles" (note that > I'm not talking about ICC profiles) specifying the primaries, gamma and > white point of other colorspaces so they can be used instead of sRGB? > > If that was possible, it would be accessible to people like Elle who > want to create such profiles and edit in a specific colorspace without > the unbounded transforms and data, right? In babl BablModel is the data types that encodes color space/TRC aspects apart from data type in babl. One can register a new model called "r'g'b'"; and then without much code register a new set of named formats for different data types. One might have to manage such formats in GIMP/GEGL code; similar to the BablFormats that represent indexed mode pixel formats - with their associated color palettes. After this; babl will work for all kinds of formats based on this model - albeit a bit slowly. One might have to add architectural changes to babl to permit implementing accelerated conversions taking just chromacity/TRC meta-data into account. The changes/additions to babl are similar to what would be needed for later; perhaps optional; lcms2 support for generic ICC profile backed color models. I wouldn't want this as a global toggle for a GIMP composition/session though; image data in a GIMP composition can come from multiple image sources with different source color spaces / chromacities. It would be nice if some GEGL operations / GIMP view of channels etc. could query what the source pixelformat of data in a GeglBuffer is; thus operations must store the pixelformat of incoming buffers in created buffers; compositing ops should probably forward the format of the "input" pad. In operations where specifying the "interpolation" space makes sense like gradient rendering; it could default to the "image data source format" and offer sRGB based linear and gamma corrected, CIE Lab and maybe some more. /pippin _______________________________________________ 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
