Hello, > I can give it a try. If I understand it correctly, > gimp-8bit.c only implements u8->float conversions, which > seem to be picked up by BABL correctly, so the problem lies > in the float->u8 conversions that are computed by > ReferenceFish. Is that correct? I just had a short look into the babl code; it looks like there is a float->u8 conversion implemented using the 16bit lookup table in extensions/gegl-fixups.c. In fact, it looks like the same algorithm as described in the pdf paper. I do not have much time to look at it now, I just noticed that the function gggl_float_to_index16 (line 130) is not inlined, but I guess it should be. Could you try to check if that helps? Greets Richard > > Regards, > Jan > > On 09:14, Wed 14 May 08, Sven Neumann wrote: >> Hi, >> >> currently the GEGL operations in GIMP are very slow. I have done some >> basic profiling yesterday and it appears that the main problem is the >> conversion from floating point to 8bit. Here is where the most time is >> being spent. So it doesn't really make much sense to optimize the >> operations in GIMP or the point filters in GEGL. We need to look at the >> babl conversions first. >> >> Here's an interesting paper that outlines how to do conversion from >> linear light floating point image data to 8-bit sRGB using a relatively >> small lookup table: >> >> http://mysite.verizon.net/spitzak/conversion/sketches_0265.pdf >> >> That is exactly the conversion that the tile sink executes. It would >> help us a lot if someone could implement this. The file >> extensions/gimp-8bit.c would probably be the right place to put this >> code. I am afraid I am not going to find time for this. Is anyone else >> interested in working on this? >> >> >> Sven > _______________________________________________ > Gegl-developer mailing list > Gegl-developer@xxxxxxxxxxxxxxxxxxxxxx > https://lists.XCF.Berkeley.EDU/mailman/listinfo/gegl-developer _______________________________________________ Gegl-developer mailing list Gegl-developer@xxxxxxxxxxxxxxxxxxxxxx https://lists.XCF.Berkeley.EDU/mailman/listinfo/gegl-developer
