Image processing apparatus, image processing method, recording medium, and program

Patent metadata

Field	Value
Publication number	US-10129437-B2
Application number	US-201515504798-A
Country	US
Kind code	B2
Filing date	Aug 19, 2015
Priority date	Aug 25, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An image processing apparatus includes a color separation unit separating image data into a luminance component and a color component; a processing unit generating second image data of the luminance component by manipulating pixel values of multi-resolution image data generated from first image data of the luminance component and reconstructing the manipulated multi-resolution image data; and a composition unit compositing the second image data of the luminance component with image data of the color component. Further, the processing unit generates the second image data of the luminance component based on pixel values which are adjusted by using parameters in accordance with pixel values of the image data of the color component.

First claim

The invention claimed is:

1. An image processing apparatus comprising:
a memory; and
a processor that is coupled to the memory and that is configured to
separate image data into a luminance component and a color component;
generate second image data of the luminance component by manipulating pixel values of multi-resolution image data generated from first image data of the luminance component and reconstructing the manipulated multi-resolution image data; and
composite the second image data of the luminance component with image data of the color component,
wherein the processor is configured to generate the second image data of the luminance component based on pixel values which are adjusted by using parameters in accordance with pixel values of the image data of the color component, and
wherein the processor is configured to generate the second image data of the luminance component by compositing the first image data of the luminance component with third image data of the luminance component, which is generated by the reconstructing, by using the parameters in accordance with the pixel values of the image data of the color component.

2. The image processing apparatus according to claim 1 ,
wherein the processor is configured to generate the second image data of the luminance component by reconstructing a composition between the multi-resolution image data, which is generated from the first image data of the luminance component, and the manipulated multi-resolution image data, in which the pixel values of the multi-resolution image data are manipulated, by using the parameters in accordance with the pixel values of the image data of the color component.

3. The image processing apparatus according to claim 1 ,
wherein the parameters indicate ratios when the first image data of the luminance component and the third image data of the luminance component are composited with each other, and
wherein the greater the pixel values of the image data of the color component, the greater the ratios of the first image data of the luminance component when the first image data of the luminance component and the third image data of the luminance component are composited with each other.

4. The image processing apparatus according to claim 2 ,
wherein the parameters indicate ratios when the multi-resolution image data, which are generated from the first image data of the luminance component, and the manipulated multi-resolution image data, in which the pixel values of the multi-resolution image data are manipulated, are composited with each other and
wherein the greater the pixel values of the image data of the color component, the greater the ratios of the multi-resolution image data generated from the first image data of the luminance component when the multi-resolution image data, which are generated from the first image data of the luminance component, and the manipulated multi-resolution image data, in which the pixel values of the multi-resolution image data are manipulated are composited with each other.

5. The image processing apparatus according to claim 4 ,
wherein the parameters are determined for each of resolution levels of multi-resolution image data which are generated from the image data of the color component.

6. The image processing apparatus according to claim 1 ,
wherein the parameters are set to one or zero when pixel values of image data of saturation values calculated based on the image data of the color component are less than or equal to a predetermined value C th1 or greater than or equal to a predetermined value C th2 (C th1 <C th2 ).

7. The image processing apparatus according to claim 1 ,
wherein the processor is configured to generate the multi-resolution image data of a Laplacian pyramid from the first image data of the luminance component.

8. The image processing apparatus according to claim 1 ,
wherein the processor is configured to generate the multi-resolution image data by performing a discrete wavelet transformation on the first image data of the luminance component.

9. The image processing apparatus according to claim 1 ,
wherein the processor is configured to manipulate to increase pixel values which are less than one tenth of a dynamic range of the first image data of the luminance component and which are included in the pixel values of the multi-resolution image data generated from the first image data of the luminance component.

10. An image processing method comprising:
separating image data into a luminance component and a color component;
generating second image data of the luminance component by manipulating pixel values of multi-resolution image data generated from first image data of the luminance component and reconstructing the manipulated multi-resolution image data; and
compositing the second image data of the luminance component with image data of the color component,
wherein the second image data of the luminance component are generated based on pixel values which are adjusted by using parameters in accordance with pixel values of the image data of the color component, and
wherein the second image data of the luminance component are generated by compositing the first image data of the luminance component with third image data of the luminance component, which is generated by the reconstructing, by using the parameters in accordance with the pixel values of the image data of the color component.

11. A non transitory recording medium storing a program causing a computer to execute an image processing method comprising:
separating image data into a luminance component and a color component;
generating second image data of the luminance component by manipulating pixel values of multi-resolution image data generated from first image data of the luminance component and reconstructing the manipulated multi-resolution image data; and
compositing the second image data of the luminance component with image data of the color component,
wherein the second image data of the luminance component are generated based on pixel values which are adjusted by using parameters in accordance with pixel values of the image data of the color component, and
wherein the second image data of the luminance component are generated by compositing the first image data of the luminance component with third image data of the luminance component, which is generated by the reconstructing, by using the parameters in accordance with the pixel values of the image data of the color component.

Assignees

• Ricoh Co Ltd

Inventors

• Yasutomi Kei

Classifications

• H04N1/6005 Primary

  with luminance or chrominance signals, e.g. LC1C2, HSL or YUV · CPC title

• H04N1/6027

  Correction or control of colour gradation or colour contrast (H04N1/6058 takes precedence) · CPC title

• H04N9/646

  for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters · CPC title