Image signal processor and image signal processing method

Abstract

This invention provides an image signal processor and an image signal processing method that improve the accuracy of correction for defective pixels and other defects. [Solution] The image decoding processor includes: a defective pixel detection unit that detects defective pixels among identical pixels that have the same attributes as the target pixels included in the target kernel; a pattern determination unit that, if defective pixels exist, determines the pattern of the target kernel based on the pixel data of the pixels included in the target kernel; and a defective pixel interpolation unit that, if a defective pixel is located in the texture region of the pattern, interpolates the target pixel using the pixel data of heterogeneous pixels that have different attributes from the target pixel and are located in the texture region, and the pixel data of identical pixels that are located in the texture region.

Claims

1. A defective pixel detection unit detects defective pixels among similar characteristic pixels, which are pixels containing the target pixel and having the same attributes as each other, included in the target kernel. If the aforementioned defective pixels exist, a pattern determination unit determines the pattern of the target kernel based on the pixel data of the pixels included in the target kernel. If the defective pixel is located in the texture region of the pattern, a pixel interpolation unit interpolates the target pixel using the pixel data of a non-similar characteristic pixel located in the texture region, and the pixel data of a similar pixel located in the texture region. An image signal processor, including...

2. The image signal processor according to claim 1, wherein the attribute includes at least one of a color filter or a channel.

3. The image signal processor according to claim 1, wherein the defective pixel detection unit determines the pixel with the highest pixel data to be a defective pixel if the difference in pixel data between the pixel with the highest pixel data and the second highest pixel data among the same type of pixels is greater than or equal to a threshold value.

4. The image signal processor according to claim 1, wherein the defective pixel detection unit determines the pixel with the lowest pixel data to be a defective pixel if the difference in pixel data between the pixel with the lowest pixel data and the second lowest pixel among the same type of pixels is greater than or equal to a threshold value.

5. The image signal processor according to claim 1, wherein the pattern determination unit determines the pattern based on at least one of first comparison data obtained by comparing pixel data between pixels located in the texture region, or second comparison data obtained by comparing pixel data between pixels located in the texture region and pixels located outside the texture region.

6. The image signal processor according to claim 5, wherein the pattern includes at least one of a horizontal pattern, a vertical pattern, a slash pattern, or a backslash pattern.

7. The image signal processor according to claim 1, wherein the pixel interpolation unit interpolates the target pixel using the pixel data of a pixel in contact with a pixel located symmetrically to the defective pixel with respect to the target pixel, and the pixel data of a pixel in contact with the target pixel, among the heterogeneous pixels.

8. The image signal processor according to claim 7, wherein the pixel interpolation unit interpolates the target pixel using a value obtained by subtracting the pixel data of a pixel adjacent to the symmetrically located pixel from the pixel data of a pixel adjacent to the target pixel, and a value obtained by adding the pixel data of a pixel adjacent to the symmetrically located pixel.

9. The image signal processor according to claim 7, wherein the pixel interpolation unit interpolates the target pixel using a value obtained by dividing the pixel data of a pixel adjacent to the symmetrically located pixel by the pixel data of the pixel adjacent to the target pixel, and a value obtained by multiplying the pixel data of the pixel adjacent to the symmetrically located pixel by the pixel data of the pixel adjacent to the target pixel.

10. The image signal processor according to claim 1, wherein the pixel interpolation unit interpolates the target pixel using pixel data of pixels located on a direction line corresponding to the pattern, centered on the target pixel.

11. The image signal processor according to claim 1, wherein the target kernel has a monochrome pattern, a quad pattern, a nona pattern, a Q×Q pattern, or an RGBW pattern.

12. A pattern determination unit that determines the pattern of the target kernel based on the pixel data of the pixels of the target kernel, including the target pixels, When identical defective pixels having the same attributes as the target pixel are located in the texture region of the pattern, a heterogeneous pixel determination unit generates heterogeneous pixel data that includes at least one of the inclinations or ratios between heterogeneous pixels located in the texture region, which are heterogeneous (un-similar characteristic) pixels having different attributes from the target pixel. A pixel interpolation unit that interpolates the target pixels based on the aforementioned heterogeneous pixel data, An image signal processor, including...

13. The image signal processor according to claim 12, wherein the attribute includes at least one of a color filter or a channel.

14. The image signal processor according to claim 12, wherein the pixel interpolation unit interpolates the target pixel using the pixel data of a pixel adjacent to a pixel located symmetrically to the same type of defective pixel with respect to the target pixel, and the pixel data of a pixel adjacent to the target pixel.

15. The image signal processor according to claim 14, wherein the pixel interpolation unit interpolates the target pixel using a value obtained by subtracting the pixel data of a pixel adjacent to the symmetrically located pixel from the pixel data of a pixel adjacent to the target pixel, and a value obtained by adding the pixel data of a pixel adjacent to the symmetrically located pixel.

16. The image signal processor according to claim 14, wherein the pixel interpolation unit interpolates the target pixel using a value obtained by dividing the pixel data of a pixel adjacent to the symmetrically located pixel by the pixel data of the pixel adjacent to the target pixel, and a value obtained by multiplying the pixel data of the pixel adjacent to the symmetrically located pixel by the pixel data of the pixel adjacent to the target pixel.

17. The steps include determining which pixels are defective among the same type of pixels that have the same attributes as the target pixels included in the target kernel, and If the aforementioned defective pixels exist, the step of determining the pattern of the target kernel based on the pixel data of the pixels included in the target kernel, If the defective pixel is located in the texture region of the pattern, the step of interpolating the target pixel using the pixel data of heterogeneous pixels, which have different attributes from the target pixel, located in the texture region, and the pixel data of homogeneous pixels, which are located in the texture region. An image signal processing method, including the following.

18. The image signal processing method according to claim 17, wherein the step of determining a defective pixel includes determining the pixel with the highest pixel data to be a defective pixel if the difference in pixel data between the pixel with the highest pixel data and the second highest pixel among the same type of pixels is greater than or equal to a threshold.

19. The image signal processing method according to claim 17, wherein the step of determining the pattern includes determining the pattern based on at least one of first comparison data obtained by comparing pixel data between pixels located in the texture region of the pattern, or second comparison data obtained by comparing pixel data between pixels located in the texture region and pixels located outside the texture region.

20. The image signal processing method according to claim 17, wherein the step of interpolating the target pixel includes a step of interpolating the target pixel using pixel data of a pixel that is in contact with a pixel that is located symmetrically with respect to the defective pixel from the target pixel, and pixel data of a pixel that is in contact with the target pixel, from among the heterogeneous pixels.

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