Method, apparatus and recording medium for color correction

• US 20010035989A1
• Filed: 04/27/2001
• Published: 11/01/2001
• Est. Priority Date: 04/28/2000
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Takemoto, Fumito
• Granted Patent: US 6,975,437 B2
• Time in Patent Office: Days
• US Class Current: 358/518
• CPC Class Codes: H04N 1/62 Retouching, i.e. modification of isolated colours only or in isolated picture areas only
• CPC Class Codes: H04N 1/628 Memory colours, e.g. skin or sky

Abstract

Appropriate color correction is carried out when image data obtained by a digital camera are printed. Correction degrees for lightness, chroma, and hue are set for specific colors R, G, B, C, M, Y, YG, BS, SK(HL), SK(MD), SK(SD) in an image represented by the image data. In an L*a*b* color space, a distance between a center color of each of the specific colors and a color comprising the image represented by the image data is found. Based on the distance, the correction degrees for lightness, chroma and hue of the specific colors are subjected to weighted addition, and correction values for lightness, chroma and hue are obtained. Based on the correction values, lightness, chroma and hue of the image represented by the image data are corrected, and processed image data are obtained.

Claims

1. A color correction method for obtaining processed image data by carrying out color correction processing on image data obtained by a digital camera, the method comprising the steps of:

setting correction degrees for lightness, chroma and hue of predetermined specific colors;

obtaining correction values for lightness, chroma and hue by weighted addition of the correction degrees of the lightness, the chroma and the hue of the specific colors, based on a distance in a uniform color difference space between a center color of each of the specific colors and a color comprising an image represented by the image data; and

obtaining the processed image data by correcting lightness, chroma and hue of the image represented by the image data, based on the correction values of the lightness, the chroma and the hue.

2. A color correction method as defined in

claim 1

, wherein the specific colors include a skin color.

3. A color correction method as defined in

claim 2

, wherein the skin color is classified into a plurality of types according to lightness, chroma and/or hue thereof, and included in the specific color.

4. A color correction method as defined in any one of

claims 1

to

3

, further comprising the steps of:

displaying the image represented by the image data;

receiving specification of a desired position in the image displayed on the display means; and

including a color at the specified position in the specific colors.

5. A color correction apparatus for obtaining processed image data by carrying out color correction processing on image data obtained by a digital camera, the color correction apparatus comprising:

correction degree setting means for setting correction degrees of lightness, chroma and hue of predetermined specific colors;

weighted addition means for obtaining correction values for lightness, chroma and hue by carrying out weighted addition of the correction degrees of the lightness, the chroma and the hue of the specific colors, based on a distance in a uniform color difference space between a center color of each of the specific colors and a color comprising an image represented by the image data; and

correction means for obtaining the processed image data by correcting lightness, chroma and hue of the image represented by the image data, based on the correction values of the lightness, the chroma and the hue.

6. A color correction apparatus as defined in

claim 5

, wherein the specific colors include a skin color.

7. A color correction apparatus as defined in

claim 6

, wherein the skin color is classified into a plurality of types according to lightness, chroma, and hue thereof, and included in the specific colors.

8. A color correction apparatus as defined in any one of

claims 5

to

7

, further comprising:

display means for displaying the image represented by the image data; and

specification means for specifying a desired position in the image displayed on the display means, whereby

a color at the specified position the image is included in the specific colors.

9. A computer-readable recording medium storing a program to cause a computer to execute a color correction method for obtaining processed image data by carrying out color correction processing on image data obtained by a digital camera, the program comprising the procedures of:

setting correction degrees for lightness, chroma and hue of predetermined specific colors;

obtaining correction values for lightness, chroma and hue by weighted addition of the correction degrees of the lightness, the chroma and the hue of the specific colors, based on a distance in a uniform color difference space between a center color of each of the specific colors and a color comprising an image represented by the image data; and

obtaining the processed image data by correcting lightness, chroma and hue of the image represented by the image data, based on the correction values of the lightness, the chroma and the hue.

10. A computer-readable recording medium as defined in

claim 9

, wherein the specific colors include a skin color.

11. A computer-readable recording medium as defined in

claim 10

, wherein the skin color is classified into a plurality of types according to lightness, chroma, and/or hue thereof, and included in the specific colors.

12. A computer-readable recording medium as defined in any one of

claims 9

to

11

, the program further comprising the procedures of:

displaying the image represented by the image data on display means; and

receiving specification of a desired position in the image displayed on the display means, whereby

a color at the specified position in the image is included in the specific colors.