Adaptive dequantization method and apparatus in video coding
First Claim
1. An adaptive dequantization method in video coding, comprising:
- determining an image area, in a current decoded image, corresponding to a first transform coefficient set, the first transform coefficient set comprising N transform coefficients of any color space component in the current decoded image, and N being a positive integer;
obtaining decoded pixel information of the image area, the decoded pixel information comprising spatial neighborhood pixel information of the image area;
calculating a quantization adjustment factor according to the decoded pixel information and a pixel average (Pavg), the Pavg being an average of luminance components of multiple pixels corresponding to the decoded pixel information or an average of the same color space components of the multiple pixels; and
performing dequantization on the first transform coefficient set according to the quantization adjustment factor to obtain a second transform coefficient set.
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Abstract
An adaptive dequantization method and apparatus in video coding includes, a statistical feature of a background area in which a current transform block is located is estimated using spatial neighborhood information, or temporal neighborhood information, or spatial neighborhood information and temporal neighborhood information of the transform block, a quantization adjustment factor for dequantization is adaptively derived, and dequantization processing is flexibly adjusted. Hence quantization adjustment information is transmitted in a bitstream, according to the method and the apparatus, and extra bit overheads are not required to transmit the quantization adjustment information, thereby further improving coding efficiency.
17 Citations
20 Claims
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1. An adaptive dequantization method in video coding, comprising:
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determining an image area, in a current decoded image, corresponding to a first transform coefficient set, the first transform coefficient set comprising N transform coefficients of any color space component in the current decoded image, and N being a positive integer; obtaining decoded pixel information of the image area, the decoded pixel information comprising spatial neighborhood pixel information of the image area; calculating a quantization adjustment factor according to the decoded pixel information and a pixel average (Pavg), the Pavg being an average of luminance components of multiple pixels corresponding to the decoded pixel information or an average of the same color space components of the multiple pixels; and performing dequantization on the first transform coefficient set according to the quantization adjustment factor to obtain a second transform coefficient set. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An adaptive dequantization method in video coding, comprising:
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determining an image area (X), in a current decoded image, corresponding to a first transform coefficient set, the first transform coefficient set comprising N transform coefficients of any color space component in the current decoded image, and N being a positive integer; obtaining temporal neighborhood pixel information of X; calculating a quantization adjustment factor according to a first variance (Pvar), the Pvar being a variance of luminance components of multiple pixels or a variance of the same color space components of the multiple pixels, and the color space component corresponding to the first transform coefficient set; and performing dequantization processing on the first transform coefficient set according to the quantization adjustment factor to obtain a second transform coefficient set. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. An adaptive dequantization apparatus in video coding, comprising:
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a memory comprising instructions; and a processor coupled to the memory and configured to execute the instructions, which causes the processor to be configured to; determine an image area, in a current decoded image, corresponding to a first transform coefficient set, the first transform coefficient set comprising N transform coefficients of any color space component in the current decoded image, and N being a positive integer; obtain decoded pixel information of the image area, the decoded pixel information comprising spatial neighborhood pixel information of the image area; calculate a quantization adjustment factor according to third function (ƒ
3(Pmax−
Pmin)) of a difference between a maximum pixel value (Pmax) and a minimum pixel value (Pmin), the Pmax being a maximum value of luminance components of multiple pixels corresponding to the decoded pixel information or a maximum value of the same color space components of the multiple pixels, the Pmin being a minimum value of the luminance components of the multiple pixels or a minimum value of the same space components of the multiple pixels, and the color space component corresponding to the first transform coefficient set; andperform dequantization on the first transform coefficient set according to the quantization adjustment factor to obtain a second transform coefficient set. - View Dependent Claims (18, 19, 20)
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Specification