IMAGE PROCESSING APPARATUS AND IMAGE PROCESSING METHOD

• US 20160350627A1
• Filed: 05/24/2016
• Published: 12/01/2016
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kano, Yutaka, Ohta, Ayako, Kanda, Hidehiko, Komamiya, Eiji, Yazawa, Takeshi
• Granted Patent: US 10,127,481 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41J 2/2132 Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding methods for local corrections by dot omission, image edge enhancement, or multi-pass mask selection G06K15/102; colour conversion H04N1/40
• CPC Class Codes: G06K 15/107 Mask selection
• CPC Class Codes: G06K 15/1836 Rasterization
• CPC Class Codes: G06K 15/1843 Changing size or raster resolution

Abstract

With respect to an area quantized by using an area of part in a quantization pattern and also without using an area of the other part in the quantization pattern in quantized data, a mask pattern part corresponding to the area of the part among mask pattern parts constituted by dividing a mask pattern is applied.

Claims

1. An image processing apparatus for generating recording data used for each of a plurality of relative scanning operations of a recording head in an intersecting direction that intersects with a predetermined direction with respect to a unit area on a recording medium, the recording head including an ejection opening column having a plurality of ejection openings for ejecting ink arranged in the predetermined direction, the recording data specifying ejection or non-ejection of the ink to each of a plurality of pixel areas equivalent to a plurality of pixels in the unit area, the image processing apparatus comprising:

an obtaining unit configured to obtain multi-value data corresponding to an image recoded in the unit area;

a quantization unit configured to generate quantized data by repeatedly applying a quantization pattern to the multi-value data obtained by the obtaining unit in the predetermined direction; and

a distribution unit configured to generate the recording data by distributing the quantized data generated by the quantization unit to the plurality of scanning operations by using a plurality of mask patterns corresponding to the plurality of scanning operations, each of the plurality of mask patterns being mutually associated with the quantization pattern,

wherein the distribution unit applies, to an area quantized by using an area of part in the quantization pattern and also without using an area of the other part in the quantization pattern in the quantized data generated by the quantization unit, each of a plurality of mask pattern parts obtained by dividing each of the plurality of mask patterns in the predetermined direction corresponding to the area of the part.

2. The image processing apparatus according to claim 1, wherein the distribution unit applies each of the plurality of mask patterns to the area quantized by using all areas in the quantization pattern in the quantized data.

3. The image processing apparatus according to claim 1, further comprising:

a conveyance unit configured to convey the recording medium in the predetermined direction by a first distance during the plurality of scanning operations of the recording head,

wherein a length of the quantization pattern in the predetermined direction is different from an integer multiple of the first distance and is also different from one over an integer multiple of the first distance.

4. The image processing apparatus according to claim 3,

wherein the conveyance unit further conveys the recording medium in the predetermined direction by a second distance that is shorter than the first distance during the plurality of scanning operations of the recording head, and

wherein the length of the quantization pattern in the predetermined direction is different from an integer multiple of the second distance and is also different from one over an integer multiple of the second distance.

5. The image processing apparatus according to claim 4, wherein the conveyance unit conveys the recording medium by the first distance in a case where the recording head is located in a central part in the predetermined direction on the recording medium and conveys the recording medium by the second distance in a case where the recording head is located in an end part in the predetermined direction on the recording medium.

6. The image processing apparatus according to claim 1,

wherein a threshold for specifying ejection or non-ejection of the ink to each of the plurality of pixel areas is set with respect to each of the plurality of pixels in the quantization pattern, and

wherein permission or prohibition of the ink ejection to each of the plurality of pixel areas is specified with respect to each of the plurality of pixels in each of the plurality of mask patterns.

7. The image processing apparatus according to claim 1,

wherein a threshold for specifying the number of times to perform the ink ejection to each of the plurality of pixel areas is set with respect to each of the plurality of pixels in the quantization pattern, and

wherein the number of times to permit the ink ejection to each of the plurality of pixel areas is set with respect to each of the plurality of pixels in each of the plurality of mask patterns.

8. The image processing apparatus according to claim 1, wherein, in a case where a value indicated by the multi-value data obtained by the obtaining unit is a first value, the quantization pattern and the predetermined mask pattern are determined in a manner that an arrangement of dots based on the recording data generated by the distribution unit on the basis of the quantized data generated by the quantization unit and a predetermined mask pattern among the plurality of mask patterns does not exhibit white noise characteristics.

9. The image processing apparatus according to claim 8, wherein, in a case where the value indicated by the multi-value data obtained by the obtaining unit is the first value, the quantization pattern and the predetermined mask pattern are determined in a manner that the arrangement of the dots based on the recording data generated by the distribution unit on the basis of the quantized data generated by the quantization unit and the predetermined mask pattern does not exhibit red noise characteristics.

10. The image processing apparatus according to claim 9, wherein, in a case where the value indicated by the multi-value data obtained by the obtaining unit is the first value, the quantization pattern and the predetermined mask pattern are determined in a manner that the arrangement of the dots based on the recording data generated by the distribution unit on the basis of the quantized data generated by the quantization unit and the predetermined mask pattern exhibit blue noise characteristics.

11. The image processing apparatus according to claim 8, wherein, in a case where the value indicated by the multi-value data obtained by the obtaining unit is a second value that is different from the first value, the quantization pattern and the predetermined mask pattern are determined in a manner that the arrangement of the dots based on the recording data generated by the distribution unit on the basis of the quantized data generated by the quantization unit and the predetermined mask pattern does not exhibit the white noise characteristics.

12. The image processing apparatus according to claim 8, wherein, in a case where the value indicated by the multi-value data obtained by the obtaining unit is the first value, the quantization pattern and a second mask pattern that is different from the predetermined mask pattern among the plurality of mask patterns are determined in a manner that the arrangement of the dots based on the recording data generated by the distribution unit on the basis of the quantized data generated by the quantization unit and the second mask pattern does not exhibit the white noise characteristics.

13. The image processing apparatus according to claim 1, further comprising:

a memory that stores the quantization pattern and the plurality of mask patterns.

14. The image processing apparatus according to claim 13,

wherein the memory further stores the plurality of mask pattern parts, and

the distribution unit generates the recording data by using the plurality of mask pattern parts stored in the memory.

15. The image processing apparatus according to claim 13, wherein the distribution unit divides the plurality of mask patterns stored in the memory to generate the plurality of mask pattern parts and generates the recording data by using the plurality of generated mask pattern parts.

16. The image processing apparatus according to claim 1, wherein the quantization pattern and each of the plurality of mask patterns have a mutually same size.

17. The image processing apparatus according to claim 1, further comprising:

the recording head.

18. An image processing method for generating recording data used for each of a plurality of relative scanning operations of a recording head in an intersecting direction that intersects with a predetermined direction with respect to a unit area on a recording medium, the recording head including an ejection opening column having a plurality of ejection openings for ejecting ink arranged in the predetermined direction, the recording data specifying ejection or non-ejection of the ink to each of a plurality of pixel areas equivalent to a plurality of pixels in the unit area, the image processing method comprising:

obtaining multi-value data corresponding to an image recoded in the unit area;

generating quantized data by repeatedly applying a quantization pattern to the obtained multi-value data in the predetermined direction;

generating the recording data by distributing the generated quantized data to the plurality of scanning operations by using a plurality of mask patterns corresponding to the plurality of scanning operations, each of the plurality of mask patterns being mutually associated with the quantization pattern; and

applying, to an area quantized by using an area of part in the quantization pattern and also without using an area of the other part in the quantization pattern in the generated quantized data, each of a plurality of mask pattern parts obtained by dividing each of the plurality of mask patterns in the predetermined direction corresponding to the area of the part.