- gimp_rgb_list_names() ported as gimp_color_list_names() using NUL-terminated
GimpColorArray.
- GimpColorHexEntry uses the new function (and is therefore now GimpRGB free!).
- gimp_rgb_parse_name() deleted as it's unused since my previous commit.
With all this, gimprgb-parse.c is now deleted from the repository! \o/
New functions with the same name as these functions are created, except without
the length argument (i.e. it's equivalent to calling these with -1).
The reason for this is that using strings with a length variant which may be
negative to switch to NUL-terminated strings are not bindable. At least in our
case, when testing in Python, the input string ended up as corrupted garbage and
GObject Introspection docs warns about such interfaces:
> In particular, avoid functions taking a const char * with a signed length that
> can be set to a negative value to let the function compute the string length
> in bytes. These functions are hard to bind, and require manual overrides.
(see: https://gi.readthedocs.io/en/latest/writingbindableapis.html#strings)
So instead, I create a simple version which runs on NUL-terminated strings only
and which is bound, whereas unbinding the generic length-version (making it
C-only, or maybe usable in some other bindings which ignore the (skip)
annotation; apparently some do this).
This is meant to obsolete GeglParamColor with at least an additional argument
has_alpha which we need in GIMP. It allows to advertize when a parameter wants
an opaque color, which in particular means we know when displaying a GUI to pick
colors with alpha or not.
This is used for the gimp_color_is_perceptually_identical() function,
because the Euclidean distance in LCH is extremely limited, if not wrong
in many cases. Indeed LCH is not perfectly perceptually uniform, and for
this exact reason, the CIE defined the specific Delta E algorithms.
Later versions are also based on LCH values, so my intuition to use it
for distance was on a good start, yet these algorithms were refined a
few times to allow for corrections in perceptual uniformity
imperfections.
This was in particular needed to verify if a color is out of a CMYK
space gamut. The idea is to compare the distance of the RGB (or other)
and the CMYK version, since we cannot just check if the CMYK color is
out of the [0; 1] range (it never is). Instead if both colors are
perceptually identical, then we consider that the RGB color was inside
the CMYK space gamut.
The naive algorithm was giving any (or nearly) color as out-of-gamut.
Now using CIEDE2000, I get a much nicer results.
- New libgimpcolor functions: gimp_color_parse_hex() and gimp_color_parse_name().
- GimpColorHexEntry is now space-invaded. Though recognized color names
and hexadecimal syntax are sRGB only (because CSS and SVG
specifications explicitly say that this syntax is for sRGB values), it
is possible to enter non-sRGB values with
gimp_color_hex_entry_set_color().
- GimpColorSelection is now space-invaded.
I still see some limitations in GimpGradient, and in particular, they are still
always stored as RGB in GGR files. It would be nice if we could store the actual
color format. This way, if someone chooses a gradient stop as Lab or CMYK color,
that's what the gradient file would keep track of. But also even storing the
space of a color (instead of storing/loading always in sRGB, even though this
may still work fine as we store unbounded double values). This might warrant for
a v2 of GGR file format.
This commit also fixes loading of SVG gradient which was apparently broken
regarding hexadecimal color parsing.
Finally I improve gegl_color_set_alpha() by adding an alpha channel when the
initial format had none.
… gimp_color_is_perceptually_identical().
gimp_color_is_perceptually_identical() is meant to replace gimp_rgb_distance()
which is anyway always used to decide whether 2 colors can be considered equal.
So rather than having a distance algorithm which we won't be able to change
later on (if people start relying on specific values), let's just give the
answer directly on what's a same color (perceptually) or not.
Also now the distance is computed through the intermediate color space LCh which
seems to be one of the most perceptually uniform space, therefore a good choice
for such an algorithm (comparing distances on a non-perceptual uniform space
doesn't make very much sense, since a same distance may be perceived differently
in different subspaces).
which encapsulates a cmsHTRANSFORM and does all the pixel format
conversion magic. It has API to create transforms and proofing
transforms, and to convert pixels arrays and GeglBuffers.
Before, each place which has a transform had to keep around the
transform and its input and output Babl formats, and had to implement
lots of stuff itself. Now all that lives in GimpColorTransform,
removing lots of logic from many places, and pretty much removing lcms
from the public API entirely.
This removes including <lcms2.h>, LCMS_LIBS and LCMS_CFLAGS from
almost all directories and potentially allows to replace lcms by
something else.
This only helps to maintain proper includes in app/ and shouldn't
affect plug-ins at all, because these are supposed to only include the
main headers from libgimp/ since the beginning of time.
The gimpfootypes.h files do not have these guards, so we can continue
to maintain app/'s include policy that is very likely to error out if
wrong things are included.
2009-01-17 Michael Natterer <mitch@gimp.org>
* all files with a GPL header and all COPYING files:
Change licence to GPLv3 (and to LGPLv3 for libgimp).
Cleaned up some copyright headers and regenerated the parsers in
the ImageMap plugin.
svn path=/trunk/; revision=27913
2007-06-01 Sven Neumann <sven@gimp.org>
* libgimpcolor/Makefile.am
* libgimpcolor/gimpcolor.h
* libgimpcolor/gimpcolortypes.h
* libgimpcolor/gimpcolormanaged.[ch]: added an interface that
will
be used to implement the missing bits of color management.
* libgimpcolor/gimpcolor.def: updated.
svn path=/trunk/; revision=22691
2003-07-15 Sven Neumann <sven@gimp.org>
* libgimpcolor/gimpcolor.h: include <libgimpcolor/gimpcmyk.h>.
* modules/Makefile.am
* modules/colorsel_cmyk.c: added a simple CMYK color selector.
Alx Sa