Image correction device, image correction method, and image correction program

• US 10,346,711 B2
• Filed: 08/07/2017
• Issued: 07/09/2019
• Est. Priority Date: 03/23/2015
• Status: Active Grant

• Current Assignee: JVC Kenwood Corporation
• Original Assignee: JVC Kenwood Corporation
• Inventors: Itou, Tamotsu
• Primary Examiner(s): Eurice, Michael J
• Application Number:
  US15/671,047
• Publication Number:
  US 20170337446A1
• Time in Patent Office: 701 Days
• CPC Class Codes: G06K 15/1878 Adjusting colours image colour correction or control for documents in general H04N1/60
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 5/90 Dynamic range modification of images or parts thereof
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/0686 with two or more screen areas displaying information with different brightness or colours
• CPC Class Codes: G09G 2380/08 Biomedical applications
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/028 Circuits for converting colour display signals into monochrome display signals
• CPC Class Codes: G09G 5/377 for mixing or overlaying two or more graphic patterns G09G5/02, G09G5/397 take precedence
• CPC Class Codes: H04N 1/40012 Conversion of colour to monochrome
• CPC Class Codes: H04N 1/56 Processing of colour picture signals H04N1/52 takes precedence
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/6005 with luminance or chrominance signals, e.g. LC1C2, HSL or YUV
• CPC Class Codes: H04N 5/202 : Gamma control circuits for controlling camera response irrespective of the scene brightness H04N23/82
• CPC Class Codes: H04N 9/69 : for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

A color gamma processing unit subjects an input image to gamma correction for color on a pixel by pixel basis. A GSDF processing unit subjects the input image to gamma correction for monochrome on a pixel by pixel basis. A mixer mixes a gamma corrected value for color provided by the color gamma processing unit with a gamma corrected value for monochrome provided by the GSDF processing unit at a mixing ratio based on a pixel-by-pixel saturation value of the input image, and outputs a gamma corrected value of a pixel in the input image.

Claims

1. An image correction device comprising:

a color gamma processing unit that subjects an input image to gamma correction for color on a pixel by pixel basis;

a monochrome gamma processing unit that subjects the input image to gamma correction for monochrome on a pixel by pixel basis; and

a mixer that mixes a gamma corrected value for color provided by the color gamma processing unit with a gamma corrected value for monochrome provided by the monochrome gamma processing unit at a mixing ratio based on a pixel-by-pixel saturation value of the input image, and outputs a gamma corrected value of a pixel in the input image.

2. The image correction device according to claim 1, further comprising:

an area-by-area detection processing unit that detects a saturation value on an area by area basis; and

a selector that selects one of the pixel-by-pixel saturation value of the input image and an area-by-area saturation value of the input image detected by the area-by-area detection processing unit, wherein

the mixer mixes the gamma corrected value for color provided by the color gamma processing unit with the gamma corrected value for monochrome provided by the monochrome gamma processing unit at a mixing ratio based on the saturation value selected by the selector.

3. The image correction device according to claim 2, wherein

the selector selects the larger of the pixel-by-pixel saturation value of the input image and the area-by-area saturation value of the input image detected by the area-by-area detection processing unit.

4. The image correction device according to claim 2, wherein

the area-by-area detection processing unit includes an interpolator that determines a saturation value of a pixel in an area by interpolating a saturation value detected in units of areas by using a saturation value of an adjacent area.

5. An image correction method comprising:

subjecting an input image to gamma correction for color on a pixel by pixel basis;

subjecting the input image to gamma correction for monochrome on a pixel by pixel basis; and

mixing a gamma corrected value for color provided by said gamma correction for color with a gamma corrected value for monochrome provided by said gamma correction for monochrome at a mixing ratio based on a pixel-by-pixel saturation value of the input image, and outputs a gamma corrected value of a pixel in the input image.

6. A recording medium having embedded thereon an image correction program comprising:

a color gamma processing module that subjects an input image to gamma correction for color on a pixel by pixel basis;

a monochrome gamma processing module that subjects the input image to gamma correction for monochrome on a pixel by pixel basis; and

mixing a gamma corrected value for color provided by said color gamma processing module with a gamma corrected value for monochrome provided by said monochrome gamma processing module at a mixing ratio based on a pixel-by-pixel saturation value of the input image, and outputting a gamma corrected value of a pixel in the input image.