Image processing apparatus and method

• US 20030218764A1
• Filed: 05/14/2003
• Published: 11/27/2003
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ooyama, Takeshi
• Granted Patent: US 7,312,895 B2
• Time in Patent Office: Days
• US Class Current: 358/1.9
• CPC Class Codes: G06K 15/128 generating or processing printable items, e.g. characters
• CPC Class Codes: G06K 15/1855 Combining raster data and graphic primitives
• CPC Class Codes: H04N 1/6022 Generating a fourth subtractive colour signal, e.g. under colour removal, black masking

Abstract

This invention has as its object to prevent image quality deterioration of vector and raster image parts by allowing adjustment of the toner amount for respective objects when single image data includes both vector and raster image parts. To accomplish this, image data is separated into vector and raster image parts, a vector or raster image attribute is assigned to each pixel, and the toner amount is adjusted for each pixel of each object.

Claims

1. An image processing apparatus which processes input image data, and sends processed image data to an output device,

wherein a level of the input image data is adjusted for each object on the basis of an object attribute of the input image data, a sum total of levels of respective color components of the input image data, and performance of the output device.

2. The apparatus according to claim 1, comprising:

determination means for determining the object attribute of the input image data;

calculation means for calculating the sum total of the levels of the respective color components for respective pixels of the input image data;

comparison means for comparing the sum total of the levels of the respective color components calculated by said calculation means with an allowable input level of the output device; and

adjustment means for, when said determination means determines that the input image data has a predetermined object attribute, adjusting the level of the input image data in accordance with the comparison result of said comparison means.

3. The apparatus according to claim 2, wherein when the sum total of the levels of the respective color components calculated by said calculation means is larger than the allowable input level of the output device as a result of comparison by said comparison means, said adjustment means reduces the level of the input image data to be lower than the allowable input level of the output device.

4. The apparatus according to claim 2, wherein said determination means determines whether each pixel of the input image data belongs to a vector image or a raster image, and

when said determination means determines that a pixel of interest of the input data belongs to the vector image, said adjustment means adjusts a level of the pixel of interest.

5. The apparatus according to claim 2, wherein said determination means determines an object attribute corresponding to a larger number of pixels contained in the input image data as the object attribute of the input image data.

6. The apparatus according to claim 2, further comprising setting means for setting whether or not to make adjustment by said adjustment means.

7. The apparatus according to claim 6, wherein said setting means sets whether or not to make adjustment by said adjustment means for each object attribute.

8. The apparatus according to claim 6, wherein said setting means includes means for displaying a setup dialog which is used to set whether or not to make adjustment by said adjustment means for each object attribute.

9. The apparatus according to claim 1, wherein the image input data is CMY or CMYK image data, and the output device is an image forming device.

10. An image processing method which processes input image data, and sends processed image data to an output device,

wherein a level of the input image data is adjusted for each object on the basis of an object attribute of the input image data, a sum total of levels of respective color components of the input image data, and performance of the output device.

11. The method according to claim 10, comprising:

a determination step of determining the object attribute of the input image data;

a calculation step of calculating the sum total of the levels of the respective color components for respective pixels of the input image data;

a comparison step of comparing the sum total of the levels of the respective color components calculated in the calculation step with an allowable input level of the output device; and

an adjustment step of adjusting, when it is determined in the determination step that the input image data has a predetermined object attribute, the level of the input image data in accordance with the comparison result in the comparison step.

12. The method according to claim 11, wherein the adjustment step includes a step of reducing, when the sum total of the levels of the respective color components calculated in the calculation step is larger than the allowable input level of the output device as a result of comparison in the comparison step, the level of the input image data to be lower than the allowable input level of the output device.

13. The method according to claim 11, wherein the determination step includes a step of determining whether each pixel of the input image data belongs to a vector image or a raster image, and

the adjustment step includes a step of adjusting, when it is determined in the determination step that a pixel of interest of the input data belongs to the vector image, a level of the pixel of interest.

14. The method according to claim 11, wherein the determination step includes a step of determining an object attribute corresponding to a larger number of pixels contained in the input image data as the object attribute of the input image data.

15. The method according to claim 11, further comprising a setting step of setting whether or not to make adjustment in the adjustment step.

16. The method according to claim 15, wherein the setting step includes a step of setting whether or not to make adjustment in the adjustment step for each object attribute.

17. The method according to claim 15, wherein the setting step includes a step of displaying a setup dialog which is used to set whether or not to make adjustment in the adjustment step for each object attribute.

18. The method according to claim 10, wherein the image input data is CMY or CMYK image data, and the output device is an image forming device.