Color space values corresponding to classification identifiers

Patent metadata

Field	Value
Publication number	US-10893173-B2
Application number	US-201716338181-A
Country	US
Kind code	B2
Filing date	Jan 30, 2017
Priority date	Jan 30, 2017
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

In an example, an image processing system may include an identification engine, a map engine, and a control engine. In that example, the identification engine may identify a color mapping resource in response to a classification identifier corresponding to image data, the map engine may map the image data with the color mapping resource having color space clause corresponding to the classification identifier, and the control engine may generate control data for operating a print apparatus to print based on the color mapping resource.

First claim

What is claimed is:

1. An image processing system comprising:
a memory storing instructions; and
a processor, by executing the instructions stored in the memory, to:
identify a color mapping resource in response to a classification identifier corresponding to image data;
identify a coverage attribute threshold corresponding to the classification identifier that is different from a default coverage attribute threshold;
select a look-up table (LUT) corresponding to the identified coverage attribute threshold that is different from the default coverage attribute threshold;
map the image data with the color mapping resource having color space values corresponding to the classification identifier; and
generate control data for operating a print apparatus to print based on the color mapping resource.

2. The system of claim 1 , further comprising:
a print fluid ejection system to deposit colorants according to the control data,
wherein the processor, by further executing the instructions stored in the memory, is to determine the classification identifier based on a characteristic of the image data.

3. The system of claim 1 , wherein the classification identifier corresponds to a region of the image data.

4. The system of claim 3 , wherein the region of the image data includes an edge or a line.

5. An image processing system comprising:
a memory storing instructions; and
a processor, by executing the instructions stored in the memory, to:
identify a color mapping resource in response to a classification identifier corresponding to image data;
retrieve a general look-up table (LUT);
compute a modified version of the general LUT based on an identified coverage attribute threshold;
map the image data with the color mapping resource having color space values corresponding to the classification identifier; and
generate control data for operating a print apparatus to print based on the color mapping resource.

6. The system of claim 5 , further comprising:
a print fluid ejection system to deposit colorants according to the control data,
wherein the processor, by further executing the instructions stored in the memory, is to determine the classification identifier based on a characteristic of the image data.

7. An image processing system comprising:
a memory storing instructions; and
a processor, by executing the instructions stored in the memory, to:
identify a color mapping resource in response to a classification identifier corresponding to image data;
map the image data with the color mapping resource having color space values corresponding to the classification identifier; and
generate control data for operating a print apparatus to print based on the color mapping resource by combining a first set of halftone image data processed using a first look-up table (LUT) with image data corresponding to a first coverage attribute threshold and a second set of halftone image data processed using a second LUT corresponding to a second coverage attribute threshold that is different from the first coverage attribute threshold.

8. The system of claim 7 , further comprising:
a print fluid ejection system to deposit colorants according to the control data,
wherein the processor, by further executing the instructions stored in the memory, is to determine the classification identifier based on a characteristic of the image data.

9. A non-transitory computer-readable storage medium comprising a set of instructions executable by a processor resource to:
perform a color mapping process using color space values derived from a modified color space based on a classification identifier corresponding to input image data,
wherein the modified color space includes color area coverages that are:
increased when the classification identifier corresponds to a detail feature; or
decreased when the classification identifier corresponds to a non-detail feature.

10. The medium of claim 9 , wherein the color space values are Neugebauer Primaries (NPs) and the color area coverages are Neugebauer Primary Area Coverages (NPACs).

11. The medium of claim 10 , wherein the set of instructions is executable by the processor resource to:
modify a look-up table (LUT) of color space values to include the modified color space values by:
removing coverages in order of coverage size until a threshold number of NPs is achieved and rescaling any remaining coverage areas; or
adding noise to the color space values above a coverage attribute threshold and rescaling any remaining coverage areas.

12. The medium of claim 10 , wherein the set of instructions is executable by the processor resource to:
remove NPs from an NPAC retrieved from a LUT by:
omission of NPs with a color area coverage less than a coverage size threshold or
elimination of NPs with a relatively smallest area coverage until a coverage complexity threshold is achieved;

maintain a coverage size of a blank NP with respect to unmodified color space values; and
rescale coverages of non-blank NPs to increase coverage in response to the removal of NPs.

13. The medium of claim 10 , wherein the set of instructions is executable by the processor resource to:
select a halftone resource based on the classification identifier;
produce an output image halftone using the selected halftone resource; and
generate control data for a print apparatus from the output image halftone.

14. The medium of claim 9 , wherein the classification identifier corresponds to a region of the image data.

15. The medium of claim 14 , wherein the region of the image data includes an edge or a line.

16. A method of color mapping for use with a print apparatus having multiple print bars comprising:
determining to use a number of print bars based on a first classification identifier corresponding with a first set of image data;
selecting a first look-up table (LUT) of color space values based on the first classification identifier, the first LUT having color space values with coverage sizes that are different than default color space values corresponding to unclassified image data;
performing a color mapping process for the first set of image data using the first LUT corresponding to the first classification identifier; and
generating control data for printing a halftone image based on a result of the color mapping process performed on the first set of image data using the first LUT corresponding to the first classification identifier.

17. The method of claim 16 , comprising:
retrieving a first Neugebauer Primary Area Coverage (NPAC) from the first LUT to use with the color mapping process of the first set of image data;
selecting a second LUT of color space values based on a second classification identifier corresponding to a second set of image data;
retrieving a second NPAC from the second LUT to use with the color mapping process of the second set of image data corresponding to the second classification identifier; and
generating a halftone image of the first set of image data and the second set of image data using the first NP for image data corresponding to the first classification identifier and using the second NP for image data corresponding to the second classification identifier.

18. The method of claim 17 , wherein:
the first LUT includes NPACs with a number of Neugebauer Primaries (NPs) per NPAC that is different from a number of NPs per NPAC of the second LUT; and
the first LUT includes rescaled area coverages corresponding to a difference in area coverage of the NPs in corresponding LUT entries.

Assignees

• Hewlett Packard Development Co

Inventors

• Morovic Peter
• Morovic Jan
• Vidal Fortia Joan
• Abello Rosello Lluis

Classifications

• H04N1/00068

  Calculating or estimating · CPC title

• H04N1/00015

  Reproducing apparatus · CPC title

• H04N1/6061 Primary

  involving the consideration or construction of a gamut surface · CPC title

• H04N1/00082

  Adjusting or controlling (interrupting an operation H04N1/00915; inhibiting an operation H04N1/00925) · CPC title

• H04N1/00047

  using an image not specifically designed for the purpose · CPC title