Image processing apparatus

• US 20040047504A1
• Filed: 01/24/2003
• Published: 03/11/2004
• Est. Priority Date: 09/09/2002
• Status: Active Grant

• Current Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Original Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Inventors: Suzuki, Hiroyuki, Kusumoto, Keiji
• Granted Patent: US 7,317,828 B2
• Time in Patent Office: Days
• US Class Current: 382/166
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence

Abstract

In an image processing apparatus, a compression processor compresses a color image data, a storage device stores the compressed data, and an expansion processor expands the data read from the storage device. A first background controller controls background of the color image data not yet compressed by the compression processor, while a second background controller controls background of the image data expanded by the expansion processor. A controller activates either the first background controller or the second background controller.

Claims

1. An image processing apparatus comprising:

a compression processor which compresses a color image data;

a storage device which stores the data compressed by said compression processor;

an expansion processor which expands the data read from said storage device;

a first background controller which controls background of the color image data not yet compressed by said compression processor;

a second background controller which controls background of the image data expanded by said expansion processor; and

a controller which activates either said first background controller or said second background controller.

2. The image processing apparatus according to claim 1, further comprising an operation panel with which an operator instructs said controller to activate one of said first and second background controllers.

3. The image processing apparatus according to claim 2, wherein said controller activates said first background controller in a default mode.

4. The image processing apparatus according to claim 1, wherein the color image data to be compressed is specified in a color system including lightness component.

5. The image processing apparatus according to claim 4, further comprising a converter which converts color image data of red, green and blue to the data in the color system including lightness component, and a reverse converter which converts the data expanded by said expansion processor to the color image data of red, green and blue.

6. The image processing apparatus according to claim 4, wherein the color system including lightness component is Lab color system.

7. The image processing apparatus according to claim 4, further comprising an operational panel with which an operator sets a threshold lightness level, wherein said first background controller removes the color image data having lightness level equal to or smaller than the threshold lightness level.

8. The image processing apparatus according to claim 7, wherein said first background controller multiplies the lightness data with a coefficient in correspondence to the threshold lightness level.

9. The image processing apparatus according to claim 4, wherein said controller generates a histogram of the lightness data to determine a lightness level having a maximum frequency as a threshold lightness level, and said second background controller removes the color image data having lightness level smaller than the threshold lightness level.

10. The image processing apparatus according to claim 1, further comprising a color sensor which senses a color image of a document to provide the color image data.

11. A copying machine comprising:

an image processor which receives a full color image data and sends print data therefor; and

a print engine which receives and prints the print data;

wherein said image processor comprising;

a compression processor which compresses a color image data;

a storage device which stores the data compressed by said compression processor;

an expansion processor which expands the data read from said storage device;

a first background controller which controls background of the color image data not yet compressed by said compression processor;

a second background controller which controls background of the image data expanded by said expansion processor; and

a controller which activates either said first background controller or said second background controller.

12. An image processing apparatus comprising:

a compression processor which compresses a color image data;

a storage device which stores the data compressed by said compression processor;

an expansion processor which expands the data read from said storage device;

a first background controller which controls background of the color image data not yet compressed by said compression processor;

a second background controller which controls background of the image data expanded by said expansion processor;

a decider which decides which of manual background control mode and automatic background control mode is set, a background control level being set manually in the manual background control mode or automatically based on the image data in the automatic background control mode; and

a controller which activates said first background controller when said decider decides that the manual background control mode is set and activates said second background controller when said decider decides that the automatic background control mode is set.

13. The image processor according to claim 12, further comprising a converter which converts input color image data to color image data in a color system including lightness component.

14. The image processor according to claim 13, wherein said first background controller removes background by multiplying the lightness component data with a coefficient set with an operation panel.

15. The image processor according to claim 13, further comprising a histogram generator which generates a histogram based on the lightness component data, wherein said second background controller removes background based on the background control level determined according to the generated histogram.