Re: [Gimp-developer] Lab conversion, GEGL, RGB space, Illuminant

2010-08-13 Thread James Cox
jcup...@gmail.com wrote I open up an image to make a small change to one corner. Why did other parts of my image change color slightly?  Because Round tripping through a color profile is not lossless (some profiles are worse than others). Well, that's certainly true. Though open/edit/save,

Re: [Gimp-developer] Lab conversion, GEGL, RGB space, Illuminant

2010-08-12 Thread James Cox
Graeme Gill wrote: yahvuu wrote: The only sane way to achieve this is, like James says, to choose a single color space and stick with it. This is possible with floating point processing (GEGL). All imported image data gets convert to, say scRGB, processing take places, and on export data

Re: [Gimp-developer] Lab conversion, GEGL, RGB space, Illuminant

2010-08-12 Thread James Cox
On 12 August 2010 00:17, Edward Coffey edward.cof...@gmail.com wrote: My understanding of GEGL (and, I assume, a fully GEGL-based GIMP) is that colors will be represented internally as linear-light RGB(A) structures. Given that (and please correct me if I'm already veering off track), how are

Re: [Gimp-developer] Lab conversion, GEGL, RGB space, Illuminant

2010-08-11 Thread James Cox
Disclaimer: I am not a color buff. Anybody who actually *knows* about that stuff, please chime in. PAL/SECAM vs sRGB = While writing the Lab/LCH layer mode stuff, I wondered so far why the result is still slightly different from the current GEGL implementation of

Re: [Gimp-developer] Airbrush/Brush Banding Effect At Low Pressure/Opacity

2009-11-18 Thread James Cox
Christopher Howard wrote: Jay Cox wrote: On Oct 20, 2009, at 1:39 PM, Sven Neumann wrote: Hi, On Tue, 2009-10-20 at 12:22 -0800, Christopher Howard wrote: Though having a far from sufficient understanding of how the GIMP brush painting process works, it seems to me like this is the