Color Color Processing
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The document discusses color processing methods, highlighting the importance of lightness and hue in geometric constructions related to color. It outlines two algorithms that prioritize color coordinates over spatial ones, resulting in improved LUTs that maintain color purity and smooth transitions without compromising gamut. The findings are applied to high-end graphics printers, suggesting further exploration of color processing techniques in imaging pipelines.
Color Color Processing
- 1. COLOR COLOR PROCESSING JÁN MOROVIČ, PETER MOROVIČ, JORDI ARNABAT, VICTOR DIEGO, PERE GASPARIN, XAVI FARIÑA HP INC., BARCELONA, CATALONIA, SPAIN
- 2. SHOULD WE TREAT DIFFERENT COLOR SETS WITH SAME GEOMETRIES AS SAME? DOES COLOR = GEOMETRY?
- 3. NOT ALL LONG DIAGONALS ARE CREATED EQUAL FIRST STEPS: “LIGHTNESS” IS SPECIAL
- 4. MAKING CHOICES ABOUT GEOMETRIC CONSTRUCTION WITH COLOR IN MIND INTUITION: COLOR VERSUS GEOMETRIC BASIS Lightness?
- 5. SCALING THE AUDIENCE BY (1/2)12 (IN MEMORIAM OF STEPHEN HAWKING) BUT, WHAT DOES THAT LOOK LIKE IN MATHS?
- 6. BUT, WITH A PINCH OF HAND-WAVING AND NOW FOR SOMETHING COMPLETELY THE SAME:
- 7. FROM BASIC COLOR RAMPS TO FULL LUT THE RGB LUT SKELETON 0 250 50 200 100 250 Blue 150 150 200 Green 200 150 Red 100 250 100 50 50 0 0 0 250 50 200 100 250 Blue 150 150 200 Green 200 150 Red 100 250 100 50 50 0 0
- 8. L-PLANE, HUE-NEIGHBOR INTERPOLATION K W R G B C Y M K W R G B C Y M device RGB cube initial transitions K W R G B C Y M l-plane l-plane (2D projection) YC M W→RW→B W→G triangle selection YC M W→RW→B W→G W→K In W→K barycentric coordinates Y W→R In W→K wWK wWR wWy L-PLANE: MORE GRADUAL TRANSITION; BETTER CONTINUITY DELAUNAY: SUDDEN CHANGES; ”STEP” EFFECT
- 9. COLOR COLOR SMOOTHING K W R G B C Y M ramps K W R G B C Y M W & K points faces interior K W R G B C Y M K W R G B C Y M
- 10. NEUTRAL AXIS PRESERVATION 2 4 6 8 10 12 14 10 20 30 40 50 60 70 80 90 LAB profiling target (before o, after s) 2 4 6 8 10 12 14 0 50 100 150 200 250 RGB profiling target (before ko, after gx)
- 11. IMAGING PIPELINE INTERACTIONS ED HANSNode-to-node differences
- 12. CONCLUSIONS • Two color processing methods: processing color coordinates instead of generic spatial ones • Choices made on basis of lightness and hue instead of analytical cube tessellations / circumsphere volumes • Locations within color gamut & whether neutral color or not • Result: LUTs that are better behaved, where purity is preserved and smoothness delivered w/o gamut sacrifice • Both color color processing algorithms applied to imaging pipeline resources of six and nine ink HP Designjet Z6 & Z9+ high-end graphics printers in May ’18 • Next steps: identify further opportunities for color color processing (and by extension property property processing in 3D) HP Pixel Control HP Pixel Control HP Pixel Control
- 13. THANK YOU!