IMAGE PROCESSING APPARATUS AND IMAGE PROCESSING METHOD

• US 20090244631A1
• Filed: 03/30/2009
• Published: 10/01/2009
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ota, Takatoshi, Ito, Koji, Hansaki, Tomoyuki, Sugiura, Hiroaki
• Granted Patent: US 8,194,285 B2
• Time in Patent Office: Days
• US Class Current: 358/3.30
• CPC Class Codes: H04N 1/405 Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels

Abstract

An image processing apparatus configured to generate recording data used in an image forming processing for carrying out an image formation by performing a recording scan by plural times on a same image region on a recording medium, includes a division unit for dividing input image data into image data for each recording scan, a quantization unit for quantizing, based on the divided image data for each recording scan, the image data for each recording scan, and a generation unit for generating, based on the quantized image data for each recording scan, recording data for each recording scan, in which the division unit divides the input image data into the image data for each recording scan based on a division rate periodically varying in accordance with a spatial position of an image represented by the input image data.

Claims

1. An image processing apparatus configured to generate recording data used in an image forming processing for carrying out an image formation by performing a recording scan by plural times on a same image region on a recording medium, the image processing apparatus comprising:

a division unit configured to divide input image data into image data for each of the recording scans;

a quantization unit configured to quantize, based on the divided image data for each of the recording scans, the image data for each of the recording scans; and

a generation unit configured to generate, based on the quantized image data for each of the recording scans, recording data for each of the recording scans,

wherein the division unit divides the input image data into the image data for each of the recording scans based on a division rate periodically varying in accordance with a spatial position of an image represented by the input image data.

2. The image processing apparatus according to claim 1, wherein the division rate includes a division rate periodically varying in a main scanning direction of a recording read of the image forming apparatus.

3. The image processing apparatus according to claim 1, wherein the division rate includes a division rate periodically varying in a sub scanning direction of a recording read of the image forming apparatus.

4. The image processing apparatus according to claim 1, wherein the division rate includes a division rate periodically varying in a main scanning direction and a sub scanning direction of a recording read of the image forming apparatus.

5. The image processing apparatus according to claim 1, wherein the division rate includes a division rate varying in any one of a moire manner and a circular symmetric manner.

6. The image processing apparatus according to claim 1, wherein the division rate includes a division rate varying at an arbitrary angle with respect to any one of a main scanning direction and a sub scanning direction of a recording head of the image forming apparatus.

7. The image processing apparatus according to claim 1, wherein the quantization unit performs the quantization based on an error diffusion processing.

8. The image processing apparatus according to claim 7, wherein the quantization unit performs the quantization based on the error diffusion processing of a dot separation type.

9. The image processing apparatus according to claim 1, wherein the quantization unit performs the quantization based on a dither matrix method.

10. The image processing apparatus according to claim 1, wherein the division unit performs the division on a part of color components among respective color components constructing the image data.

11. The image processing apparatus according to claim 1, wherein the division unit performs the division on all color components among respective color components constructing the image data.

12. An image processing method of generating recording data used in an image forming processing for carrying out an image formation by performing a recording scan by plural times on a same image region on a recording medium, the image processing method comprising:

dividing input image data into image data for each of the recording scans;

quantizing, based on the divided image data for each of the recording scans, the image data for each of the recording scans; and

generating, based on the quantized image data for each of the recording scans, recording data for each of the recording scans,

wherein the dividing step includes dividing the input image data into the image data for each of the recording scans based on a division rate periodically varying in accordance with a spatial position of an image represented by the input image data.

13. A computer-readable storage medium storing a computer program having computer-executable instructions for causing a computer to execute the image processing method according to claim 12.