Image processing circuit and associated image processing method

An image processing circuit, comprising:

• a receiving circuit, configured to receive image data;
• a sharpness processing circuit, configured to perform a high-pass filtering operation on the image data to generate processed image data;
• a luminance variation processing circuit, configured to determine a high frequency component of each pixel within the image data and calculate, for each pixel, a difference between the high frequency component of the pixel and the high frequency component of neighboring pixel(s) to generate auxiliary image data;
• and
• an output circuit, configured to generate an output image according to the processed image data and the auxiliary image data,
• wherein the output circuit is configured to multiply the processed image data by a weighting value to obtain a first result, multiply the auxiliary image data by another weighting value to obtain a second result, and add the first result and the second result to generate the output image.

An image processing method, comprising:

• receiving image data;
• performing a high-pass filtering operation on the image data to generate processed image data;
• determining a high frequency component of each pixel within the image data;
• calculating, for each pixel, a difference between the high frequency component of the pixel and the high frequency component of neighboring pixel(s) to generate auxiliary image data;
• and
• generating an output image according to the processed image data and the auxiliary image data,
• wherein the image data comprises a plurality of consecutive pixels, and the step of determining a high frequency component of each pixel within the image data further comprises:
• calculating, for each pixel of the plurality of consecutive pixels, the high frequency component of the pixel according to whether a group of N pixels on one side of the pixel and a group of M pixels on another side of the pixel both have pixel(s) whose luminance are higher than luminance of the pixel, or both have pixel(s) whose luminance are lower than the luminance of the pixel.