Image processing apparatus and image processing method generating quantized data based on a determined print operation

Patent metadata

Field	Value
Publication number	US-9876940-B2
Application number	US-201615040449-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Feb 20, 2015
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

An image processing apparatus has a determination unit that determines a print operation to be performed and a generation unit that generates quantized data for printing a dot by comparing a threshold value and the multi-valued data. In a case of performing a first print operation, dot arrangement of the multiple types of inks printed on the print medium by the print unit on a basis of pieces of quantized data generated by the generation unit is higher in exclusiveness and dispersibility between or among dots of the multiple types of inks and lower in an overlap rate between or among the dots of the multiple types of inks than dot arrangement of the multiple types of inks printed on the print medium by the print unit on a basis of the pieces of quantized data generated by the generation unit in the case of performing the second print operation.

First claim

What is claimed is:

1. An image processing apparatus for processing data used for printing an image on a print medium by ejecting multiple types of mutually different inks from a print unit, the image processing apparatus comprising:
a memory storing computer executable code; and
one or more processors which executes the code to perform the following steps:
determining a print operation to be performed, from among multiple print operations, which perform printing with use of the print unit, at least including a first print operation and a second print operation, wherein an unevenness of an image due to a displacement of a print position on a print medium in the second print operation is larger than an unevenness of an image due to a displacement of a print position on a print medium in the first print operation;
acquiring multi-valued data for each of the multiple types of inks;
generating, in accordance with the determined print operation to be performed, quantized data for printing a dot by comparing a threshold value acquired by a threshold value acquisition unit, wherein the threshold value is arranged in a threshold value matrix providing an array of threshold values corresponding to pixel positions and corresponds to the target pixel, and the multi-valued data with each other for each of the multiple types of inks; and
outputting the generated quantized data used by the print unit to eject multiple types of inks,
wherein, in a case where the determined print operation is the second print operation, the generating generates quantized data for a first type of ink with use of threshold values obtained from a first threshold value matrix and generates quantized data for a second type of ink with use of threshold values obtained from a second threshold value matrix having different threshold value arrangements than the first threshold value matrix, and
wherein, in a case where the determined print operation is the first print operation, a dot arrangement of the first and second types of inks printed on the print medium by the print unit on a basis of the generated quantized data is higher in exclusiveness and dispersibility between or among dots of the first and second types of inks and lower in an overlap rate between or among the dots of the first and second types of inks than a dot arrangement of the multiple types of inks printed on the print medium by the print unit on a basis of the generated quantized data in the case where the determined print operation is the second print operation.

2. The image processing apparatus according to claim 1 , wherein:
in the case where the determined print operation is the first print operation, the generating generates quantized data for the first type of ink with use of threshold values obtained from a third threshold value matrix, and offsets the threshold values of the third threshold value matrix on the basis of the multi-valued data for the first type of ink, and the generating generates quantized data for the second type of ink with use of the offset threshold values.

3. The image processing apparatus according to claim 2 , wherein the third threshold value matrix has a blue noise characteristic.

4. The image processing apparatus according to claim 3 , wherein each of the first and second threshold value matrices is a threshold value matrix providing a threshold value array by which a dot arrangement of a halftone dot shape is provided as a result of a quantization process of halftone multi-valued data.

5. The image processing apparatus according to claim 2 , wherein:
a memory area adapted to, in the case where the determined print operation is the first print operation, store the third threshold value matrix, and a memory area adapted to, in the case where the determined print operation is the second print operation, store the first and second threshold value matrices separately respectively prepared for the first and second types of inks are same; and
a capacity of the third threshold value matrix is twice or more than a capacity of the first and second threshold value matrix corresponding to one ink.

6. The image processing apparatus according to claim 1 , wherein the first print operation is a print operation for photo paper, and the second print operation is a print operation for plain paper.

7. The image processing apparatus according to claim 1 , wherein the first print operation is a print operation using multipass printing of which a relative pass number between the print medium and the print unit is N or more, and the second print operation is a print operation using multipass printing of which the relative pass number is less than N or one-pass printing.

8. The image processing apparatus according to claim 1 , wherein in the first print operation, a distance between the print medium and the print unit is a predetermined distance, and in the second print operation, the distance is larger than the predetermined distance.

9. The image processing apparatus according to claim 1 , wherein the first print operation is a single-sided print operation that performs printing only on a single side of a print medium, and the second print operation is a double-sided print operation that performs printing on both sides of a print medium.

10. The image processing apparatus according to claim 1 , wherein he first print operation is a print operation for a front surface of a print medium in a double-sided print operation that performs printing on both sides of a print medium, and the second print operation is a print operation for a back surface of the print medium of which the front surface is printed in the double-sided print operation.

11. The image processing apparatus according to claim 1 , wherein the first print operation is a print operation that forms a dot having a first size on the print medium, and the second print operation is a print operation that forms a dot having a second size smaller than the first size on the print medium.

12. The image processing apparatus according to claim 1 , wherein in the first print operation, a relative scanning speed between the print unit and the print medium is a predetermined speed, and in the second print operation, the relative scanning speed is larger than the predetermined speed.

13. The image processing apparatus according to claim 1 , wherein in the first print operation, the first and second types of inks are ejected from the print unit at a first ejection speed, and in the second print operation, the print unit ejects the first and second types of inks at a second ejection speed lower than the first ejection speed.

14. The image processing apparatus according to claim 1 , wherein the first print operation is a print operation based on unidirectional scanning of the print unit with respect to a print medium, and the second print operation is a print operation based on bidirectional scanning of the print unit with respect to a print medium.

15. The image processing apparatus according to claim 1 , wherein the first print operation is a margin print operation that performs printing with margins being provided along sides of the print medium, and the second print operation is a marginless print operation that performs printing without providing any margin along the sides of the print medium.

16. The image processing apparatus according to claim 1 , wherein the generating includes the multi-valued data to the quantized data having three or more values in either case of the first print operation or the second print operation.

17. The image processing apparatus according to claim 1 , wherein

Assignees

• Canon Kk

Inventors

• Yamada Akitoshi
• Miyazaki Shinichi
• Kato Masao

Classifications

• H04N1/4053

  with threshold modulated relative to input image data or vice versa · CPC title

• H04N1/58

  Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction (H04N1/62 takes precedence) · CPC title

• H04N1/52 Primary

  Circuits or arrangements for halftone screening · 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