Image processing method and image processing device

Abstract

An image processing method and an image processing apparatus are disclosed. The image processing method includes: performing a first weighted average calculation on luminance data of a plurality of pixels in a first mask to obtain a background average value for a target pixel, wherein the target pixel is the center pixel of the first mask; performing a second weighted average calculation on luminance data of a plurality of pixels in a second mask to obtain a foreground average value for the target pixel, wherein the target pixel is also the center pixel of the second mask; generating a sharpness level based on a gain value and the difference between the luminance data of the target pixel and the foreground average value for the target pixel; and adjusting the luminance data of the target pixel according to the sharpness level.

Claims

1. An image processing method, comprising: A first weighted average calculation is performed on the brightness data of multiple pixels in a first mask to obtain a background average value for a target pixel, which is the center pixel of the first mask; a second weighted average calculation is performed on the brightness data of multiple pixels in a second mask based on the background average value for the target pixel to obtain a foreground average value for the target pixel, which is also the center pixel of the second mask; a sharpness level is generated based on a gain value and the difference between the brightness data of the target pixel and the foreground average value for the target pixel; and the brightness data of the target pixel is adjusted based on the sharpness level.

2. The image processing method as described in claim 1, wherein the step of performing the first weighted average calculation includes: A background extractor is used to apply a first weighted average filter to the brightness data of multiple pixels in the first mask.

3. The image processing method as described in claim 1, wherein the step of performing the second weighted average calculation includes: A second weighted averaging filter is applied to the brightness data of the plurality of pixels in the second mask, wherein the second weighted averaging filter is formed by the absolute difference between the brightness data of each of the plurality of pixels in the second mask and the average value of the background.

4. The image processing method of claim 1, wherein the step of generating the sharpness level based on the gain value and the difference between the brightness data of the target pixel and the foreground average value with respect to the target pixel includes: The difference between the brightness data of the target pixel and the foreground average value for the target pixel is calculated as the original sharpness level; And multiply the original sharpness level by the gain value to produce the sharpness level.

5. The image processing method as described in claim 1, wherein the step of adjusting the brightness data of the target pixel according to the sharpness level includes: The brightness data of the target pixel is added to the sharpness level to generate the adjusted brightness data of the target pixel.

6. An image processing apparatus, comprising: An image sharpening filter, wherein the image sharpening filter includes: a foreground averaging filter configured to generate a foreground average value for a target pixel; a first calculation circuit coupled to the foreground averaging filter and configured to generate a sharpness level based on a gain value and a difference between luminance data of the target pixel and the foreground average value for the target pixel; and a luminance adjustment circuit configured to adjust the luminance data of the target pixel according to the sharpness level, wherein the foreground averaging filter includes a background extractor and a second calculation circuit, wherein the background extractor is configured to perform a first weighted average calculation on multiple luminance data of multiple pixels in a first mask to obtain a background average value for the target pixel, the target pixel being the center pixel of the first mask, and the second calculation circuit is configured to perform a second weighted average calculation on multiple luminance data of multiple pixels in a second mask based on the background average value for the target pixel to obtain a foreground average value for the target pixel, the target pixel also being the center pixel of the second mask.

7. The image processing apparatus of claim 6, wherein the background extractor applies a first weighted averaging filter to the brightness data of the plurality of pixels in the first mask.

8. The image processing apparatus of claim 6, wherein the second computing circuit applies a second weighted averaging filter to the luminance data of the plurality of pixels in the second mask, wherein the second weighted averaging filter is formed by the absolute difference between each of the luminance data of the plurality of pixels in the second mask and the background average value.

9. The image processing apparatus of claim 6, wherein the first computing circuit calculates a raw sharpness level by measuring the difference between luminance data of the target pixel and the foreground average value with respect to the target pixel, and multiplies the raw sharpness level by the gain value to generate the sharpness level.

10. The image processing apparatus of claim 6, wherein the brightness adjustment circuit adjusts the brightness data of the target pixel by adding the brightness data of the target pixel to the sharpness level to generate adjusted brightness data of the target pixel.

11. The image processing apparatus of claim 6, wherein the first computing circuitry comprises: A first inverter is coupled to the foreground averaging filter, wherein the first inverter inverts the foreground average value on the target pixel to a negative foreground average value; A first adder is coupled to the output of the first inverter, wherein the first adder adds the brightness data of the target pixel and the average value of the negative foreground as the result of the first adder; and a first multiplier, coupled to the first adder and receiving the gain value, wherein the first multiplier multiplies the result of the first adder by the gain value to produce the sharpness level.

12. The image processing apparatus of claim 6, wherein the second computing circuitry comprises: A second inverter is coupled to the background extractor, wherein the second inverter inverts the background average value to a negative background average value; A second adder, coupled to the second inverter, wherein the second adder adds the brightness data of the target pixel and the average value of the negative background as the result of the second adder; an absolute value calculator, coupled to the output of the second adder, wherein the absolute value calculator converts the result of the second adder into an absolute value; And a second multiplier, coupled to the output of the absolute value calculator, wherein the second multiplier calculates the foreground average value on the target pixel based on the second weight of the target pixel and the brightness data of the target pixel, and the second weight of the target pixel is the absolute value based on the result of the second adder.

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