Method and apparatus for forming and correcting color image

• US 6,088,475 A
• Filed: 12/08/1994
• Issued: 07/11/2000
• Est. Priority Date: 12/09/1993
• Status: Expired due to Fees

• Current Assignee: Akinobu Hatada, Mieko Nagashima, Toku Nagashima
• Original Assignee: Akinobu Hatada, Mieko Nagashima, Toku Nagashima
• Inventors: Hatada, Akinobu, Nagashima, Toku, Nagashima, Mieko
• Primary Examiner(s): Couso, Jose L.
• Assistant Examiner(s): Do, Anh Hong
• Application Number:
  US08/352,311
• Time in Patent Office: 2,042 Days
• Field of Search: 382/162, 382/254, 382/167, 355/68, 355/327, 355/38, 355/77, 358/518, 358/575
• US Class Current: 382/162
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/6058 Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut

Abstract

A color image forming and correcting method and apparatus employ a combination of neural network and fuzzy logic processing to reduce differences in reproducibility in the image system of device. An information value specifying a color gamut in coordinate system of the perceptual color space is entered and associated with an information value specifying a preset other color gamut by the combined techniques. The color gamut is converted into a preset color gamut in the coordinate system. The information value specifying the converted color gamut is outputted.

Claims

1. In a method for forming and correcting a color image, wherein the improvement comprises the steps of:

entering an information value representing a color gamut in a coordinate system of a perceptual color space,

associating said information value with an information value representing another gamut determined by a pre-set color gamut with the aid of a first fuzzy processing using neural network arithmetic-logical processing from one color component to another for converting, by such association, said color gamut in the coordinate system of the perceptual color space into a converted color gamut which is a prescribed color gamut, wherein the converting into the converted color gamut is done by the steps of;

comparing a pre-set reproduction color gamut of an input device and a pre-set reproduction gamut of an device for extracting a color gamut thereof,

dividing said gamut into a plural partial color areas based upon plural pre-set memory colors from one color gamut to another,

dividing the reproduction color gamut of the input device or the reproduction color gamut of the output device, whichever is narrower, into plural partial color areas based upon said memory from one color component to another, and

associating an information value representing said partial color gamut in said color gamut into an information value representing said partial color gamut in said narrower color gamut according to a color area of the input signal by way of mapping with the aid of said first fuzzy processing and

outputting an information value representing the converted color gamut in the coordinate system.

2. The method as defined in claim 1 wherein said color gamut is extracted with the aid of a fourth fuzzy processing.

3. The method as defined in claim 2 wherein said first to fourth fuzzy processing employs at least one of the fuzzy filter arithmetic-logical processing selected from the group consisting of neural network arithmetic-logic processing and a fuzzy associate memory arithmetic-logical processing.

4. An apparatus for forming and correcting a color image comprising,

a color gamut converting means configured for entering an information value representing a color gamut in a coordinate system of a perceptual color space, associating said information value with an information value representing an other color gamut determined by a pre-set color gamut with the aid of a first fuzzy processing, selected from fuzzy filter arithmetic-logical processing, neural network arithmetic-logical processing and a fuzzy associated memory arithmetic-logical processing, from one color component to another for converting, by such association, said color gamut in the coordinate system of the perceptual color space into a converted color gamut which is a prescribed color gamut, wherein said color gamut converting means comprises:

extracting means for comparing a pre-set reproduction partial color gamut of an input device and a pre-set reproduction partial color gamut of an output device and extracting a color gamut there of,

discriminating means for dividing said color gamut into plural color areas based upon plural pre-set memory colors from one color component to another, dividing the reproduction color gamut of the input device or the reproduction color gamut of the output device, whichever is narrower, into plural partial color areas based upon said memory colors from one color component to another, and

mapping means for associating an information value representing the partial color gamut in said color in said color gamut into an information value representing said partial color gamut in said narrower color gamut according to a fuzzy processing means for converting into an information value representing said converted color gamut which is a prescribed color gamut, and

outputting means for outputting the information value representing the converted color gamut in the coordinate system.

5. The apparatus as defined in claim 4 wherein said extracting means is extracting said color gamut with the aid of a fourth fuzzy processing means.

6. The apparatus as claimed in claim 5 wherein said first to fourth fuzzy processing means employs at least one of the fuzzy filter arithmetic-logical processing, neural network arithmetic-logical processing and a fuzzy associative memory arithmetic-logical processing.

7. An apparatus for forming and correcting a color image comprising,

an input converting means for converting an input image signal into an information value representing a color gamut in a coordinate system of a perceptual color space with the aid of second fuzzy processing means;

a color gamut converting means configured for entering a information value representing a color gamut in a coordinate system of a perceptual color space, associating said information value with an information value representing an other color gamut determined by a pre-set color gamut with the aid of a first fuzzy processing using neural network arithmetic-logical processing from one color component to another for converting, by such association, said color gamut in the coordinate system of the perceptual color space into a converted color gamut which is a prescribed color gamut, and outputting the information value representing the converted color gamut in the coordinate system, wherein said color gamut converting means comprises;

an extracting means for comparing a pre-set reproduction partial color gamut of an input device and a pre-set reproduction color gamut of an output device and extracting a color gamut thereof,

a discriminating means for dividing said color gamut into a plural partial color areas based upon plural pre-set memory colors from one color component to another, dividing the reproduction color gamut of the input device or the reproduction color gamut of the output device, whichever is narrower, into plural partial color areas based upon said memory colors from one color component to another; and

a mapping means for associating an information value representing the partial color gamut in said color gamut into an information value representing said partial color gamut in said narrower color gamut according to a color area of the input signal with the aid of sad first fuzzy processing means for converting into an information value representing said color gamut which is a prescribed color gamut; and

an output converting means for converting the output information value of said color gamut means into an image signal with the aid of third fuzzy processing means.