Re: [Gegl-developer] babl roadmap

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/13/2014 03:25 PM, Øyvind Kolås wrote:
> On Mon, Oct 13, 2014 at 8:19 PM, Elle Stone
> <ellestone ninedegreesbelow com> wrote:

> > As the purpose of the roadmap seems to be guiding future development, the
> > list of editing operations that rely on the chromaticities of the RGB
> > working space needs to be expanded. The following list is not complete, but
> > it's a start:
>
> The place for this would be in the GIMP wiki; where the state of
> migration from old type gimp plug-ins to GEGL ops, as well as other
> tracking state of ops are maintained.
> http://wiki.gimp.org/wiki/Hacking:Porting_filters_to_GEGL

It's OK with me if you put the information in the GIMP wiki. But if you 
attribute the information to me, please include the disclaimer that I 
think your architecture will eventually collapse under its own weight.

> > Someone should check all editing operations for perceptually encoded RGB to
> > figure out which operations depend on the chromaticities, and then add these
> > operations to the list of operations that need to be special-cased in the
> > planned "sRGB as PCS" architecture.
>
> The per-op working pixel representation are part of GEGLs design, thus
> it isn't really special casing - but specifying.

You designed an architecture around converting images to unbounded sRGB 
for editing.

After 6 months of trying to show you that your architecture has serious 
built-in problems, you finally believe me, or at least you believe 
Mansencal and Sayre. But you want to keep the architecture anyway.

So now all chromaticity-dependent editing operations will require a 
brand new "special "specifying"", unless the image is already an sRGB image.

If you didn't intend to convert all images to unbounded sRGB for 
editing, there wouldn't be any reason to "special "specify"" roughly 
half of all the editing operations that you offer through the GIMP UI.

With respect,
Elle Stone
--
Some operations that require "special "specifiying"", assuming linear 
encoding:
Channel data used as a blending layer
Channel data used for making selections
Colors/Alien Map HSL
Colors/Alien Map RGB
Colors/Auto stretch contrast
Colors/Auto stretch contrast HSV
Colors/Channel Mixer (try Margulis' "enhance green" formula)
Colors/Desaturate average
Colors/Desaturate lightness
Colors/Mono Mixer (except Luminosity-based B&W conversions)
Colors/Posterize
Colors/Threshold
Colors/Levels Gamma slider operations
Colors/Levels Red, Green, and Blue Input/Output sliders
Colors/Levels "Auto Pick" (used for white balancing images)
Filters/Artistic/Cartoon
Filters/Edge Detect/Sobel
Filters/Enhance/Red Eye Removal
Filters/Noise/HSV Noise
Filters/Noise/RGB Noise
Filters/Artistic/Soft glow
Filters/Artistic/Vignette (any color except gray, white, black)
Layer blend Mode/Burn
Layer blend Mode/Color
Layer blend Mode/Darken only
Layer blend Mode/Difference
Layer blend Mode/Divide
Layer blend Mode/Dodge
Layer blend Mode/Hard light
Layer blend Mode/Hue
Layer blend Mode/Lighten only
Layer blend Mode/Multiply
Layer blend Mode/Overlay
Layer blend Mode/Screen
Layer blend Mode/Saturation
Layer blend Mode/Value
Paint tools depend on the working space chromaticities when using the 
following blend Modes: Burn, Color, Darken only, Difference, Divide, 
Dodge, Hard light, Hue, Lighten only, Multiply, Overlay, Saturation, 
Screen, Soft light, Value.