Abstract:
A gamma correction method and system, which performs a gamma correction on an n-bit video signal to thus generate a gamma correction value. At first, a first primary index and a first sub-index are obtained by performing an index mapping on a value of the video signal. Next, a first gamma value is obtained by performing a table lookup on the first primary index and the first sub-index. Next, a second primary index and a second sub-index are obtained by performing the index mapping on the first gamma value. Next, multiple thresholds are obtained by performing the table lookup on the second primary index and the second sub-index. Finally, the value of the video signal and the multiple thresholds are compared to accordingly correct the first gamma value and generate the gamma correction value.
Abstract:
A method and apparatus for forming multi-level dither images from an input digital image are disclosed. The difference between a pixel value of the input digital image and a pixel value of a dither image corresponding to the input digital image is first determined. Next, the difference is processed by an error filter to correct the pixel value of the input digital image to generate a corrected image pixel value. The corrected image pixel value is then compared to at least two threshold values, each corresponding to a pixel value of the dither image, to determine a threshold value that is nearest to the corrected image pixel value, thereby obtaining a pixel value of the dither image corresponding to said threshold value.
Abstract:
An optimal correlation matching method for determining track behavior, which applies a video stream having a first image and a second image for locating a motion vector associated with a block of the first image in the second image, wherein each image has a plurality of blocks in rows and columns and each block has a plurality of pixels in rows and columns. The method divides a search window into a plurality of search subdivisions, selects one from the subdivisions as an operating search window, locates a center of a block respectively at all positions of the operating search window such that upon each position of the center located, pixels of the block of the first image in accordance with the operating search window are applied to corresponding pixels of the second image for performing match operation, thereby reducing required number for match operation.
Abstract:
A filtering circuit for image signal processing has a high frequency filtering circuit and a low frequency filtering circuit. The high frequency filtering circuit only includes one adder to obtain a high frequency component. The low frequency filtering circuit includes one adder and utilizes the high frequency component generated by the high frequency filtering circuit to obtain a low frequency component.