Device and method for image demosaicing

Patent metadata

Field	Value
Publication number	US-12236555-B2
Application number	US-202117561267-A
Country	US
Kind code	B2
Filing date	Dec 23, 2021
Priority date	Dec 15, 2021
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A method and processing device for image demosaicing is provided. The processing device comprises memory and a processor. The processor is configured to, for a pixel of a Bayer image which filters an acquired image using three color components, determine directional color difference weightings in a horizontal direction and a vertical direction, determine a color difference between the first color component and the second color component and a color difference between the second color component and the third color component based on the directional color difference weightings, interpolate a color value of the pixel from the one color component and the color differences and provide a color image for display.

First claim

What is claimed is:

1. An image processing device comprising:
memory; and
one or more processors that are communicatively coupled to the memory, wherein the one or more processors are collectively configured to:
obtain a Bayer image that is formed from a plurality of pixels;
determine directional color difference weightings in both a horizontal direction and a vertical direction, wherein the directional color different weightings are calculated based on color difference gradients and color variances surrounding a first pixel among the plurality of pixels;
determine a color difference that comprises a first color difference and a second color difference based on the determined directional color difference weightings surrounding the first pixel, wherein the first color difference is between a first color component and a second color component and the second color difference is between the second color component and a third color component;
interpolate a color value of the first pixel based on the directional color difference weightings and the color differences to generate an interpolated color value; and
generate a color image based on the Bayer image using the interpolated color value.

2. The image processing device of claim 1 , wherein the one or more processors are collectively configured to:
determine a linear slope and pixel position offset in a horizontal direction; and
determine a linear slope and pixel position offset in a vertical direction.

3. The image processing device of claim 1 , wherein the one or more processors are collectively configured to:
determine the color difference between the first color component and the second color component based on color difference gradients of the first color component and the second color component; and
determine the color difference between the second color component and a third color component based on color difference gradients of the second color component and the third color component.

4. The image processing device of claim 3 , wherein the one or more processors are collectively configured to:
determine pixel color differences in the horizontal direction and the vertical direction for the pixels in the Bayer image; and
determine the directional color difference weightings based on:
the pixel color differences in the horizontal and the vertical direction;
the color difference gradients of the first color component and the second color component; and
the color difference gradients of the second color component and the third color component.

5. The image processing device of claim 3 , wherein the one or more processors are collectively configured to:
determine color difference gradients in two horizontal directions and two vertical directions; and
determine the directional color difference weightings based on the color difference gradients.

6. The image processing device of claim 1 , wherein the one or more processors are collectively configured to:
determine a linear slope and a pixel position offset in a horizontal direction based on a horizontal color covariance, a horizontal color variance and horizontal mean color values; and
determine a linear slope and pixel position offset in a vertical direction based on a vertical color covariance, a vertical color variance and vertical mean color values.

7. The image processing device of claim 1 , further comprising a display device, wherein the color image is displayed on the display device.

8. The image processing device of claim 1 , further comprising an image capturing device, wherein the Bayer image is a color filtered image of an image captured by the image capturing device.

9. A method of image demosaicing comprising:
obtaining a Bayer image that is formed from a plurality of pixels;
determining directional color difference weightings in a horizontal direction and a vertical direction, wherein the directional color different weightings are calculated based on color difference gradients and color variances surrounding a first pixel among the plurality of pixels;
determining a color difference that comprises a first color difference and a second color difference based on the determined directional color difference weightings surrounding the first pixel, wherein the first color difference is between a first color component and a second color component and the second color difference is between the second color component and a third color component;
interpolating a color value of the first pixel based on the directional color difference weightings and the color differences to generate an interpolated color value; and
generating a color image based on the Bayer image using the interpolated color value.

10. The method of claim 9 , further comprising:
determining a linear slope and pixel position offset in a horizontal direction; and
determining a linear slope and pixel position offset in a vertical direction.

11. The method of claim 9 , further comprising:
determining the color difference between the first color component and the second color component based on color difference gradients of the first color component and the second color component; and
determining the color difference between the second color component and the third color component based on color difference gradients of the second color component and the third color component.

12. The method of claim 11 , further comprising:
determining pixel color differences in the horizontal direction and the vertical direction for the pixels in the Bayer image; and
determining the directional color difference weightings based on:
the pixel color differences in the horizontal and the vertical direction;
the color difference gradients of the first color component and the second color component; and
the color difference gradients of the second color component and the third color component.

13. The method of claim 12 , further comprising:
determining color difference gradients in two horizontal directions and two vertical directions; and
determining the directional color difference weightings based on the color difference gradients.

14. The method of claim 9 , further comprising:
determining a linear slope and a pixel position offset in the horizontal direction based on a horizontal color covariance, a horizontal color variance and horizontal mean color values; and
determining a linear slope and a pixel position offset in the vertical direction based on a vertical color covariance, a vertical color variance and vertical mean color values.

15. The method of claim 9 , further comprising displaying the color image on a display device.

16. The method of claim 9 , further comprising acquiring an image, filtered by a Bayer filter array, via an image capturing device.

17. An image processing device comprising:
an image capturing device configured to capture an image;
an image sensor comprising a Bayer color filter array configured to color filter the image according to a first color component, a second color component, and a third color component; and
one or more processors collectively configured to:
obtain a Bayer image that is formed from a plurality of pixels and represented as one of the first color component, the second color component, and the third color component;
determine directional color difference weightings in both a horizontal direction and a vertical direction, wherein the directional color different weightings are calculated based on color difference gradients and color variances surrounding a first pixel among the plurality of pixels;
determine a color

Assignees

• Advanced Micro Devices Inc

Inventors

• Yu Linwei
• Ye Jiangli
• Ling Yang
• Zhou Hui

Classifications

• G06T11/10

  Texturing; Colouring; Generation of textures or colours (retouching, inpainting or scratch removal G06T5/77) · CPC title

• G06V10/56

  relating to colour · CPC title

• G06T3/4015 Primary

  Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns · CPC title

• H04N9/3182 Primary

  Colour adjustment, e.g. white balance, shading or gamut (white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607) · CPC title

• G06T11/001

  Physics · mapped topic