Mechanism to perform force black color transformation

Patent metadata

Field	Value
Publication number	US-10057462-B2
Application number	US-201615383708-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Dec 19, 2016
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A printing system is disclosed. The printing system includes a color management unit including one or more color caches to store input colors and corresponding output colors and a color engine (CE) to receive input colors and perform Force-K transformations to map near black input colors into pure black output colors by dynamically identifying the near black input colors based on chroma values and effective output values.

First claim

What is claimed is:

1. A printing system comprising:
a memory to store
an interpreter module and a color management unit, including:
a first color cache to store input colors and corresponding output colors;
a second color cache to store the input colors and corresponding chroma values and effective output values; and
a color engine (CE); and

a processor to receive print job data, execute the interpreter module to convert the print job data to one or more sheetside bitmaps, execute the color management unit to cause the CE to receive the input colors and perform Force-K transformations to map near black input colors into pure black output colors by dynamically identifying the near black input colors based on the chroma values and the effective output values, and transmit the one or more sheetside bitmaps to be printed.

2. The printing system of claim 1 , further comprising a printer to print the one or more sheetside bitmaps.

3. The printing system of claim 1 , wherein the color management unit further comprises:
a first lookup table (LUT) to generate the output colors corresponding to the input colors received at the color management unit; and
a second LUT to generate the chroma values and the effective output values corresponding to the input colors received at the color management unit.

4. The printing system of claim 3 , wherein the processor further executes the color management unit to cause the CE to retrieve a chroma value and an effective output value upon a determination that an input color has been previously added to the second color cache.

5. The printing system of claim 4 , wherein the processor further executes the color management unit to cause the second LUT to generate the chroma value and the effective output value corresponding to the input color upon a determination that the input color has not been previously added to the second color cache.

6. The printing system of claim 5 , wherein the processor further executes the color management unit to cause the CE to make a determination as to whether the chroma value is less than or equal to a threshold chroma value.

7. The printing system of claim 6 , wherein the processor further executes the color management unit to cause the CE to save the effective output value in the first color cache as the output color corresponding to the input color upon a determination that the chroma value is less than or equal to the threshold chroma value.

8. The printing system of claim 7 , wherein the processor further executes the color management unit to cause the second LUT to generate an output color corresponding to the input color upon a determination that the chroma value is greater than the threshold chroma value and saves the output color in the first color cache.

9. The printing system of claim 6 , wherein the threshold chroma value is adjustable.

10. The printing system of claim 1 , wherein the color management unit further comprises a first lookup table (LUT) to generate output colors, chroma values and effective output values corresponding to the input colors received at the color management unit.

11. The printing system of claim 10 , the processor further executes the color management unit to cause the first LUT to generate the output color, the chroma value and the effective output value corresponding to the input color upon a determination that an input color has not been previously added to the first color cache.

12. The printing system of claim 11 , wherein the processor further executes the color management unit to cause the CE to make a determination as to whether the chroma value is less than or equal to a threshold chroma value and returns the effective output value as the output color upon a determination that the chroma value is less than or equal to the threshold chroma value.

13. The printing system of claim 12 , wherein the processor further executes the color management unit to cause the CE to return the generated output color upon a determination that the chroma value is greater than the threshold chroma value and saves the output color in the first color cache.

14. The printing system of claim 13 , wherein the one or more color caches further store the chroma values and the effective output values, and wherein a first color cache stores the input colors and the corresponding output colors, the chroma values and the effective output values.

15. The printing system of claim 14 , wherein the processor further executes the color management unit to cause the CE to save the generated output color, the chroma value and the effective output value in the first color cache corresponding to the input color.

16. A machine-readable medium including data that, when accessed by a machine, cause the machine to:
receive print job data;
convert the print job data to one or more sheetside bitmaps;
perform color management on the one or more sheetside bitmaps, including;
receiving an input color;
storing the input color and a corresponding output color are stored in a first color cache;
storing the input color and the corresponding chroma value and effective output value are stored in a second color cache; and
performing a Force-K transformation to map a near black input color into a pure black output color upon dynamically identifying the near black color based on the chroma value and the effective output value; and

transmitting the one or more sheetside bitmaps to be printed.

17. The machine-readable medium of claim 16 , including data that, when accessed by a machine, further cause the machine to print the one or more sheetside bitmaps.

18. The machine-readable medium of claim 17 , including data that, when accessed by a machine, further cause the machine to:
generate the output color corresponding to the input color at a first lookup table (LUT) upon a determination that the input color is not stored in the first color cache; and
generate the chroma value and the effective output value corresponding to the input color at a second LUT upon a determination that the input color is not stored in the second color cache.

19. The machine-readable medium of claim 18 , including data that, when accessed by a machine, further cause the machine to:
retrieve the chroma value and the effective output value upon a determination that the input color has been previously added to the second color cache; and
generate the chroma value and the effective output value corresponding to the input color at the second LUT upon a determination that the input color has not been previously added to the second color cache.

20. The machine-readable medium of claim 18 , including data that, when accessed by a machine, further cause the machine to:
determine whether the chroma value is less than or equal to a threshold chroma value; and
save the effective output value in the first color cache as an output color corresponding to the input color upon a determination that the chroma value is less than or equal to the threshold chroma value.

21. The machine-readable medium of claim 16 , including data that, when accessed by a machine, further cause the machine to generate the output color, the chroma value and the effective output value corresponding to the input color at a lookup table (LUT) upon a determination that the input color is not stored in the color cache.

22. The machine-readable medium of claim 21 , including data that, when accessed by a machine, further cause the machine to:
determine whether the chroma value i

Assignees

• Ferreri Vincent William
• Kailey Walter F
• Ernst Larry M
• Cebuc Claudiu Gabriel
• Ricoh Co Ltd

Inventors

• Ferreri Vincent William
• Kailey Walter F
• Ernst Larry M
• Cebuc Claudiu Gabriel

Classifications

• H04N1/6025 Primary

  using look-up tables · CPC title

• H04N1/6005

  with luminance or chrominance signals, e.g. LC1C2, HSL or YUV · CPC title

• H04N1/405

  Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels · CPC title

• H04N1/646

  Transmitting or storing colour television type signals, e.g. PAL, Lab; Their conversion into additive or subtractive colour signals or vice versa therefor (H04N1/642, H04N1/644 take precedence) · CPC title

• H04N1/6008

  with primary colour signals, e.g. RGB or CMY(K) · CPC title