Classifying and controlling encoding quality for textured, dark smooth and smooth video content
First Claim
1. A method comprising:
- for each of plural units of a picture;
analyzing content of the unit; and
using a computer, assigning a classification to the unit based at least in part on results of the analyzing the content of the unit;
using the classifications to process the plural units, wherein the classification for at least one of the plural units is a first classification type, and wherein the classification for at least one of the plural units is a second classification type indicating darker content than the first classification type; and
outputting a result of the processing;
wherein the assigning the classification to the unit includes;
comparing energy of AC coefficients for the unit to a threshold, wherein the unit is classified as a third classification type if the energy is higher than the threshold, the third classification type indicating textured content, and the first and second classification types indicating smooth content.
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Accused Products
Abstract
Techniques and tools for content classification and adaptive quantization are described. In an example implementation, a video encoding tool classifies blocks as textured, dark smooth or other smooth. The tool classifies a block as textured or non-textured by comparing the energy of AC coefficients for the block to a texture threshold, which can be set using a non-linear mapping of possible texture classification levels to possible texture thresholds. If a block is not textured, the tool further classifies the block as dark smooth or smooth depending on average intensity value for the block. Using the classification information and one or more control parameters to control bit allocation for dark smooth content relative to other smooth content, the tool encodes the video and outputs encoded video information. Example multi-pass approaches to setting the control parameters are also described.
341 Citations
19 Claims
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1. A method comprising:
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for each of plural units of a picture; analyzing content of the unit; and using a computer, assigning a classification to the unit based at least in part on results of the analyzing the content of the unit; using the classifications to process the plural units, wherein the classification for at least one of the plural units is a first classification type, and wherein the classification for at least one of the plural units is a second classification type indicating darker content than the first classification type; and outputting a result of the processing; wherein the assigning the classification to the unit includes; comparing energy of AC coefficients for the unit to a threshold, wherein the unit is classified as a third classification type if the energy is higher than the threshold, the third classification type indicating textured content, and the first and second classification types indicating smooth content. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of encoding plural video units, the method comprising:
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setting one or more parameters to control bit allocation for a first classification type relative to a second classification type during encoding of plural video units, the second classification type indicating darker content than the first classification type, wherein the setting includes; in a first pass, encoding, using a computer, the plural video units using initial values for the one or more parameters; and adjusting values of the one or more parameters based at least in part upon results of the encoding using the initial values in the first pass; in a second pass, encoding the plural video units using the adjusted values; and outputting the encoded plural video units from the second pass in a bit stream. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A video encoding system comprising:
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a user interface module adapted to receive user input that indicates a level of texture classification; an encoding control module adapted to set a texture threshold based at least in part upon the level of texture classification and using a non-linear mapping of possible values of level of texture classification to the possible values of the texture threshold, wherein the texture threshold is an AC energy threshold; one or more video encoding modules adapted to encode video using the texture threshold. - View Dependent Claims (17, 18, 19)
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Specification