Image processing apparatus and method

• US 7,312,895 B2
• Filed: 05/14/2003
• Issued: 12/25/2007
• Est. Priority Date: 05/23/2002
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ooyama, Takeshi
• Primary Examiner(s): Nguyen, Madeleine A V
• Application Number:
  US10/437,304
• Publication Number:
  US 20030218764A1
• Time in Patent Office: 1,686 Days
• Field of Search: 358/1.9, 358/518, 358/520, 358/523, 358/515, 358/536, 358/538, 358/540, 358/166, 382/167, 382/162, 382/164, 382/165
• 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, comprising:

determination means for determining whether each pixel of the input image data is contained in a vector image or a raster image;

calculation means for calculating a sum total of levels of respective color components for respective pixels of the input 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 a pixel of interest of the input data is contained in the vector image, adjusting the level of the pixel of interest based on the result of the comparison, while when said determination means determines that a pixel of interest of the input data is contained in the raster image, maintaining the level of the pixel of interest.

2. The apparatus according to claim 1, 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.

3. The apparatus according to claim 1, 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.

4. The apparatus according to claim 1, further comprising setting means for setting whether or not to make adjustment by said adjustment means.

5. The apparatus according to claim 4, wherein said setting means sets whether or not to make adjustment by said adjustment means for each object attribute.

6. The apparatus according to claim 4, 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.

7. 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.

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

determination means for determining whether each pixel of the input image data is contained in a vector image or a raster image;

calculation means for calculating a sum total of levels of respective color components for respective pixels of the input 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 a pixel of interest of the input data is contained in the vector image, adjusting the level of the pixel of interest based on the result of the comparison, while when said determination means determines that a pixel of interest of the input data is contained in the raster image, maintaining the level of the pixel of interest.

9. The method according to claim 8, 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.

10. The method according to claim 8, 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.

11. The method according to claim 8, further comprising a setting step of setting whether or not to make adjustment in the adjustment step.

12. The method according to claim 11, wherein the setting step includes a step of setting whether or not to make adjustment in he adjustment step for each object attribute.

13. The method according to claim 11, 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.

14. The method according to claim 8, wherein the image input data is CMY or CMYK image data, and the output device is an image forming device.