...and present linear RGB Histograms
This is step one: implement the feature at all (without new defaults or proper GUI, cough).
Add boolean "linear" properties to GimpOperationPointFilter, GimpCurvesConfig and GimpLevelsConfig.
In the filter, simply set the input/output formats to linear in prepare().
In the curves and levels tools, add "Linear" toggles from hell, like in the histogram dockable, and make sure things work right wrt changing and resetting the property, switching from levels to curves, and picking colors.
The result currently changes when switching a non-nop curves/levels between perceptual and linear, because adjusting the parameters between the spaces is not implemented yet.
54d3beab9c Bug 757444 - Curves and Levels should operate by default on linear RGB...
app/operations/gimpcurvesconfig.c | 28 ++++++++++++-
app/operations/gimpcurvesconfig.h | 2 +
app/operations/gimplevelsconfig.c | 28 ++++++++++++-
app/operations/gimplevelsconfig.h | 2 +
app/operations/gimpoperationcurves.c | 8 ++++
app/operations/gimpoperationlevels.c | 8 ++++
app/operations/gimpoperationpointfilter.c | 16 +++++++-
app/operations/gimpoperationpointfilter.h | 2 +
app/tools/gimpcurvestool.c | 67 +++++++++++++++++++++++++------
app/tools/gimplevelstool.c | 49 ++++++++++++++++++----
10 files changed, 186 insertions(+), 24 deletions(-)