Image quantization method and apparatus with color distortion removing quantization matrix
AssigneeSamsung Electronics Co., Ltd.
InventorsMi-yeon Lee, Bo-gun Park
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Abstract
An image quantization method and apparatus are provided in which a block with a high possibility of having color distortion is more elaborately quantized using a predetermined color distortion removing quantization matrix. The image quantization method includes determining a possibility of color distortion in the block using discrete cosine transform (DCT) coefficients and pixel values of the block of predetermined size of an image and performing initial quantization on the block using a predetermined color distortion quantization matrix to remove color distortion if the block has a high possibility of color distortion.
Claims22
An image quantization method comprising:
- determining a possibility of color distortion using discrete cosine transform (DCT) coefficients and pixel values of a block of an image;
- and
- performing initial quantization on the block using a color distortion removing quantization matrix to remove color distortion if the block has a high possibility of color distortion,
- wherein the determining the possibility of color distortion comprises determining that the block has the high possibility of color distortion if an average of differences between the pixel values of pixels in even-numbered rows of the block and the pixel values of pixels in odd-numbered rows of the block is greater than a threshold.
An image quantization apparatus comprising:
- a processor programmed to control:
- a color distortion determination unit which determines a possibility of color distortion using discrete cosine transform (DCT) coefficients and pixel values of a block of an image;
- and
- a color distortion removing unit which performs initial quantization on the block using a color distortion removing quantization matrix to remove color distortion if the block has a high possibility of color distortion,
- wherein the color distortion determination unit determines that the block has the high possibility of color distortion if an average of differences between the pixel values of pixels in even-numbered rows of the block and the pixel values of pixels in odd-numbered rows of the block is greater than a threshold.
Dependencies are inferred from the claim text.