際際滷

際際滷Share a Scribd company logo

Color Color Processing

Jan Morovic
Jan Morovic

Color imaging involves a variety of processing operations, from interpolation, via matrix transformation, to smoothing and predictive modeling. Since colors can be represented as coordinates in color space, the general methods of mathematics can be applied to them. However, if color coordinates are treated simply as generic spatial coordinates, their processing can have undesirable consequences, deriving from a disconnect between the coordinates representing a color and the color formation properties resulting in it. E.g., interpolating among colors with very different lightnesses may lead to a grainy result in print, or varying the interpolation support when processing a transition may lead to unwanted cross-contamination of colorants. To address such challenges, the present paper proposes two color processing algorithms that do take the color properties of processed coordinates into account. They can therefore, in some sense, be thought of as color color processing algorithms rather than as geometric or mathematical color processing ones. The consequences of making color-native choices when processing color data then are improved transitions, purity and grain.

1 of 13
Downloaded 12 times
COLOR COLOR PROCESSING JN MOROVI, PETER MOROVI, JORDI ARNABAT, VICTOR DIEGO, PERE GASPARIN, XAVI FARIA HP INC., BARCELONA, CATALONIA, SPAIN
SHOULD WE TREAT DIFFERENT COLOR SETS WITH SAME GEOMETRIES AS SAME? DOES COLOR = GEOMETRY?
NOT ALL LONG DIAGONALS ARE CREATED EQUAL FIRST STEPS: LIGHTNESS IS SPECIAL
MAKING CHOICES ABOUT GEOMETRIC CONSTRUCTION WITH COLOR IN MIND INTUITION: COLOR VERSUS GEOMETRIC BASIS Lightness?
SCALING THE AUDIENCE BY (1/2)12 (IN MEMORIAM OF STEPHEN HAWKING) BUT, WHAT DOES THAT LOOK LIKE IN MATHS?
BUT, WITH A PINCH OF HAND-WAVING AND NOW FOR SOMETHING COMPLETELY THE SAME:
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
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 WRWB WG triangle selection YC M WRWB WG WK In WK barycentric coordinates Y WR In WK wWK wWR wWy L-PLANE: MORE GRADUAL TRANSITION; BETTER CONTINUITY DELAUNAY: SUDDEN CHANGES; STEP EFFECT
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
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)
IMAGING PIPELINE INTERACTIONS ED HANSNode-to-node 糸庄鍖仰艶姻艶稼界艶壊
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
THANK YOU!

More Related Content

Color Color Processing

  • 1. COLOR COLOR PROCESSING JN MOROVI, PETER MOROVI, JORDI ARNABAT, VICTOR DIEGO, PERE GASPARIN, XAVI FARIA 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 WRWB WG triangle selection YC M WRWB WG WK In WK barycentric coordinates Y WR In WK 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 糸庄鍖仰艶姻艶稼界艶壊
  • 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