Color image processing apparatus

• US 5,032,904 A
• Filed: 04/04/1990
• Issued: 07/16/1991
• Est. Priority Date: 04/04/1989
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Kasahara, Nobuo, Hashimoto, Kenji, Murai, Kazuo
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): KLOCINSKI, STEVEN
• Application Number:
  US07/503,959
• Time in Patent Office: 468 Days
• Field of Search: 358/75, 358/76, 358/80, 358/78, 250/317.1, 250/318, 250/319, 382/22, 382/17, 355/326, 355/327
• US Class Current: 358/500
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/6022 Generating a fourth subtractive colour signal, e.g. under colour removal, black masking

Abstract

A color image processing apparatus for automatically feeding a plurality of documents one at a time and processing images printed on the documents. The apparatus automatically discriminates an image as to chromatic/achromatic without errors and thereby executes optimal image processing matching the kind of an image without resorting to operator'"'"'s manipulations.

Claims

1. A color image processing apparatus comprising:

image reading means comprising spectral filter means for reading a visible image printed on a document sheet in a predetermined image reading area by scanning said image;

color discriminating means for automatically determining whether or not the image is substantially monochromatic by processing image data produced by said image reading means and separated into a plurality of fundamental colors;

edge detecting means for detecting edges of the image by processing the image data;

discrimination inhibiting means for inhibiting said color discriminating means from operating when said edge detecting means has detected an edge of the image; and

control means for automatically selecting and executing either one of color processing and monochrome processing in response to a result of discrimination by said color discriminating means.

2. A color image processing apparatus comprising:

image reading means comprising spectral filter means for reading a visible image printed on a document sheet in a predetermined image reading area by scanning said image;

image processing means interconnected to an output of said image reading means;

color image recording means interconnected to an output of said image processing means and comprising a plurality of chromatic recording systems which are different in hue from each other and an achromatic recording system;

undercolor removing means included in said image processing means for processing input image data to detect an achromatic color component contained in said image, extracting as achromatic color data a value of a predetermined ratio associated with said detected achromatic color component, and subtracting a value corresponding to said extracted achromatic color data from said input image data to output chromatic color data;

color discriminating means for determining whether or not the image is substantially monochromatic by processing said chromatic color data outputted by said undercolor removing means;

edge detecting means for detecting edges of the image by processing the image data;

discrimination inhibiting means for inhibiting said color discriminating means from operating when said edge detecting means has detected an edge of the image; and

control means for causing said image reading means to read a single document image a plurality of times;

said control means fixing, during a fist image reading operation, said ratio of said undercolor removing means substantially to 100% and inhibiting said color image recording means from operating;

said control means automatically and selectively conditioning said color image recording means to either one of a color processing mode and a monochromatic processing mode in response to a result of discrimination which said color discriminating means produces with image data resulted from said first image reading operation.

3. A color image processing apparatus comprising:

image reading means comprising spectral filter means for reading a visible image printed on a document sheet in a predetermined image reading area by scanning said image;

image processing means interconnected to an output of said image reading means;

color image recording means interconnected to an output of said image processing means and comprising a plurality of chromatic recording systems which are different in hue from each other and an achromatic recording system;

background removing means included in said image processing means for correcting tone of input image data and removing a set background level from said image data;

undercolor removing means included in said image processing means for processing image data outputted by said background removing means to detect an achromatic color component contained in said image, extracting as achromatic color data a value of a predetermined ratio associated with said detected achromatic color component, and subtracting a value corresponding to said extracted achromatic color data from said input image data to output chromatic color data;

color discriminating means for determining whether or not the image is substantially monochromatic by processing the chromatic color data outputted by said undercolor removing means;

edge detecting means for detecting edges of the image by processing the image data;

discrimination inhibiting means for inhibiting said color discriminating means from operating when said edge detecting means has detected an edge of the image; and

control means for setting, when said image reading means reads a single document image for the first time, a first background level in said background removing means, fixing said ratio of said undercolor removing means at substantially 100%, and in this condition causing said color image recording means to record an achromatic color component of the image;

said control means setting, if a result of discrimination by said color discriminating means resulted from the first image reading operation is not monochromatic, a second background level in said background removing means, setting said ratio of said undercolor removing means such that said ratio is zero if tone is lower than a tone substantially the same as said first background level and has a predetermined value if otherwise, and in this condition executing a second and successive reading operations while conditioning said color image recording means for a recording mode for recording chromatic color components.

4. A color image processing apparatus comprising:

image reading means comprising spectral filter means for reading a visible image printed on a document in a predetermined image reading area by scanning said image;

color discriminating means for automatically determining whether or not the image is substantially monochromatic by processing image data outputted by said image reading means and separated into a plurality of fundamental colors;

edge detecting means for detecting edges of the image by processing the image data;

discrimination inhibiting means for inhibiting said color discriminating means from operating when said edge detecting means has detected an edge of the image;

automatic document feeding means loaded with a plurality of document sheets each carrying a visible image thereon for feeding said document sheets one by one to said predetermined image reading area of said image reading means; and

control means for switching over, on the basis of a result of discrimination by said color discriminating means, correspondence between the number of times that said image reading means scans a document sheet and the number of times that said automatic document feeding means feeds a document sheet.