svx/source/tbxctrls/Palette.cxx | 109 +++++++++++++++++++++++++++++++++++++---
1 file changed, 102 insertions(+), 7 deletions(-)
New commits:
commit 53730cc3b0a6b0228f680962f79ae6bec9e7fe02
Author: Julien Nabet <serval2...@yahoo.fr>
AuthorDate: Sun Aug 11 16:34:13 2024 +0200
Commit: Julien Nabet <serval2...@yahoo.fr>
CommitDate: Wed Aug 14 13:38:30 2024 +0200
Related tdf#135561: read ase palette with Lab colormodel
I took example on colorConversions.js from avisek, see
https://gist.github.com/avisek/eadfbe7a7a169b1001a2d3affc21052e
2 steps: convert Lab to XYZ, then XYZ to RGB
credit Avisek Das and István Ujj-Mészáros
Change-Id: I3a80259b6de1aca7fe3c308d9024e9b9f2a5a425
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/171729
Reviewed-by: Michael Meeks <michael.me...@collabora.com>
Reviewed-by: Julien Nabet <serval2...@yahoo.fr>
Tested-by: Jenkins
diff --git a/svx/source/tbxctrls/Palette.cxx b/svx/source/tbxctrls/Palette.cxx
index 8f78c0c2bc45..29158cbfcac8 100644
--- a/svx/source/tbxctrls/Palette.cxx
+++ b/svx/source/tbxctrls/Palette.cxx
@@ -78,6 +78,102 @@ static void lcl_CMYKtoRGB( float fCyan, float fMagenta,
float fYellow, float fKe
dB = std::clamp( 1.0 - fYellow, 0.0, 1.0 );
}
+// This function based on code under ALv2 - Copyright 2013 István Ujj-Mészáros
+// credit Avisek Das and István Ujj-Mészáros
+static void lcl_XYZtoRGB( float fX, float fY, float fZ, float& dR, float& dG,
float& dB)
+{
+ // Observer = 2°, Illuminant = D65
+ fX = fX / 100;
+ fY = fY / 100;
+ fZ = fZ / 100;
+
+ // X from 0 to 95.047
+ dR = fX * 3.2406 + fY * -1.5372 + fZ * -0.4986;
+ // Y from 0 to 100.000
+ dG = fX * -0.9689 + fY * 1.8758 + fZ * 0.0415;
+ // Z from 0 to 108.883
+ dB = fX * 0.0557 + fY * -0.2040 + fZ * 1.0570;
+
+ if (dR > 0.0031308)
+ {
+ dR = 1.055 * (std::pow(dR, 0.41666667)) - 0.055;
+ }
+ else
+ {
+ dR = 12.92 * dR;
+ }
+
+ if (dG > 0.0031308)
+ {
+ dG = 1.055 * (std::pow(dG, 0.41666667)) - 0.055;
+ }
+ else
+ {
+ dG = 12.92 * dG;
+ }
+
+ if (dB > 0.0031308)
+ {
+ dB = 1.055 * (std::pow(dB, 0.41666667)) - 0.055;
+ }
+ else
+ {
+ dB = 12.92 * dB;
+ }
+ dR *= 255;
+ dG *= 255;
+ dB *= 255;
+}
+
+// This function based on code under ALv2 - Copyright 2013 István Ujj-Mészáros
+// credit Avisek Das and István Ujj-Mészáros
+static void lcl_LABtoXYZ( float fL, float fa, float fb, float& dX, float& dY,
float& dZ)
+{
+ dY = (fL + 16) / 116;
+ dX = (fa / 500) + dY;
+ dZ = dY - (fb / 200);
+
+ if (std::pow(dY, 3) > 0.008856)
+ {
+ dY = std::pow(dY, 3);
+ }
+ else
+ {
+ dY = (dY - 0.137931034) / 7.787;
+ }
+
+ if (std::pow(dX, 3) > 0.008856)
+ {
+ dX = std::pow(dX, 3);
+ }
+ else
+ {
+ dX = (dX - 0.137931034) / 7.787;
+ }
+
+ if (std::pow(dZ, 3) > 0.008856)
+ {
+ dZ = std::pow(dZ, 3);
+ }
+ else
+ {
+ dZ = (dZ - 0.137931034) / 7.787;
+ }
+
+ // Observer = 2°, Illuminant = D65
+ dX = 95.047 * dX;
+ dY = 100.000 * dY;
+ dZ = 108.883 * dZ;
+}
+
+static void lcl_LABtoRGB( float fL, float fa, float fb, float& dR, float& dG,
float& dB)
+{
+ float x, y, z;
+ lcl_LABtoXYZ(fL, fa, fb, x, y, z);
+
+ lcl_XYZtoRGB(x, y, z, dR, dG, dB);
+}
+
void PaletteASE::LoadPalette()
{
SvFileStream aFile(maFPath, StreamMode::READ);
@@ -153,14 +249,13 @@ void PaletteASE::LoadPalette()
aFile.ReadFloat(nVal);
r = g = b = nVal;
}
- else
+ else if (aColorModel.equalsIgnoreAsciiCase("LAB "))
{
- float nL = 0, nA = 0, nB = 0;
- aFile.ReadFloat(nL);
- aFile.ReadFloat(nA);
- aFile.ReadFloat(nB);
- // TODO: How to convert LAB to RGB?
- r = g = b = 0;
+ float fL = 0, fA = 0, fB = 0;
+ aFile.ReadFloat(fL);
+ aFile.ReadFloat(fA);
+ aFile.ReadFloat(fB);
+ lcl_LABtoRGB(fL, fA, fB, r, g, b);
}
// Ignore color type
