System for and method of sharpness enhancement for coded digital video
AssigneeKoninklijke Philips Electronics N.V.
InventorsYibin Yang, Lilla Boroczky
Life of this patent
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Abstract
A method and system for calculating a UME for each pixel in a frame of video data. A system for enhancing sharpness of a coded digital video signal representative a frame of block-based data is provided, comprising: a system for calculating a UME of each pixel in the frame in accordance with a frame type, wherein the calculating system includes: a mechanism that defines local spatial features in the frame; a mechanism that analyzes block-based motion estimation for the frame; a mechanism that detects a scene change in the frame; and a sharpness enhancer that improves sharpness to a decoded version of the digital video signal based on said UME.
Claims29
A system for enhancing sharpness of a coded digital video signal representative of a frame of block-based data, said system comprising:
- a system for calculating a usefulness metric for enhancement (UME) of each pixel in the frame in accordance with a frame type, wherein the calculating system includes:
- a mechanism that defines local spatial features in the frame;
- a mechanism that analyzes block-based motion estimation for the frame;
- and
- a mechanism that detects a scene change in the frame;
- and
- a sharpness enhancer that improves sharpness to a decoded version of the digital video signal based on said UME.
A system for enhancing sharpness of a coded digital video signal representative of a frame of block-based data, said system comprising:
- a system for calculating a usefulness metric for enhancement (UME) of each pixel in the frame in accordance with a frame type, wherein the calculating system includes:
- a mechanism that defines local spatial features in the frame;
- a mechanism that analyzes block-based motion estimation for the frame;
- and
- a mechanism that detects a scene change in the frame;
- and
- a sharpness enhancer that improves sharpness to a decoded version of the digital video signal based on said UME,
- wherein the calculating system further includes a mechanism that analyzes macroblock and block based coding information according the formula:
- var
-
- (
- i
- ,
- j
- )
- =
- ∑
- k
- =
- -
- q
- q
-
-
- ∑
- m
- =
- -
- q
- q
-
-
- pix
-
- (
- i
- +
- k
- ,
- j
- +
- m
- )
- -
- mean
-
- wherein UME_block is a usefulness metric for a block of pixel data, q_scale is a quantization scale for a macroblock, num_bits is a number of bits to encode a luminance block, max is a function representing a maximum value for the frame, and M and N are scaling factors.
A system for enhancing sharpness of a coded digital video signal representative of a frame of block-based data, said system comprising:
- a system for calculating a usefulness metric for enhancement (UME) of each pixel in the frame in accordance with a frame type, wherein the calculating system includes:
- a mechanism that defines local spatial features in the frame;
- a mechanism that analyzes block-based motion estimation for the frame;
- and
- a mechanism that detects a scene change in the frame;
- and
- a sharpness enhancer that improves sharpness to a decoded version of the digital video signal based on said UME,
- wherein the sharpness enhancement algorithm applied is:
- out_pixel=input_pixel+UME*convolution_result,
- wherein output_pixel is a final luminance value to be used for the pixel, input_pixel is a luminance value of the input pixel, and convolution_result is a high-pass filter output.
A method for enhancing sharpness of a coded digital video signal representative of a frame of block-based data, the method comprising:
- defining local spatial features in the frame;
- analyzing block-based motion estimation for the frame;
- detecting a scene change in the frame;
- calculating a usefulness metric for enhancement (UME) of each pixel in the frame based on local spatial features block-based motion estimation and detected scene changes;
- and
- improving sharpness of the frame by applying the UME calculated for each pixel.
A method for enhancing sharpness of a coded digital video signal representative of a frame of block-based data, the method comprising:
- defining local spatial features in the frame;
- analyzing block-based motion estimation for the frame;
- detecting a scene change in the frame;
- calculating a usefulness metric for enhancement (UME) of each pixel in the frame based on local spatial features, block-based motion estimation and detected scene changes;
- and
- improving sharpness of the frame by applying the UME calculated for each pixel,
- wherein the calculating step is further based on a mechanism that analyzes macroblock coding information according the formula:
- UME_block
- =
- 1
- -
- M
- *
- (
- 1
- +
- q_scale
- N
- )
- 2
- *
- q_scale
- num_bits
- max
-
- (
- q_scale
- num_bits
- )
- wherein UME_block is a usefulness metric for a block of pixel data, q_scale is a quantization scale for a macroblock, num_bits is a number of bits to encode a luminance block, max is a function representing a maximum value for the frame, and M and N are scaling factors.
A program product stored on a recordable medium for calculating a usefulness metric for enhancement (UME) for each pixel in a frame of video data, the program product comprising:
- means for defining local spatial features in the frame;
- means for analyzing block-based motion estimation for the frame;
- means for detecting a scene change in the frame;
- and
- means for calculating the UME using the defining means, analyzing means, and detecting means.
A program product stored on a recordable medium for calculating a usefulness metric for enhancement (UME) for each pixel in a frame of video data, the program product comprising:
- means for defining local spatial features in the frame;
- means for analyzing block-based motion estimation for the frame;
- means for detecting a scene change in the frame;
- and
- means for calculating the UME using the defining means, analyzing means, and detecting means,
- wherein the means for defining local spatial features in the frame defines a variance of pixel luminance values over an n×n window covering n×n pixels for a pixel at location (i, j), said variance defined according to the equation:
- var
-
- (
- i
- ,
- j
- )
- =
- ∑
- k
- =
- -
- q
- q
-
-
- ∑
- m
- =
- -
- q
- q
-
-
-
- pix
-
- (
- i
- +
- k
- ,
- j
- +
- m
- )
- -
- mean
-
- wherein q=(n−1)/2, pix(i+k, j+m) is a pixel value at location (i+k, j+m) and mean is an average pixel value over said n×n window.
A program product stored on a recordable medium for calculating a usefulness metric for enhancement (UME) for each pixel in a frame of video data, the program product comprising:
- means for defining local spatial features in the frame;
- means for analyzing block-based motion estimation for the frame,
- means for detecting a scene change in the frame;
- and
- means for calculating the UME using the defining means, analyzing means, and detecting means,
- wherein the means for analyzing block-based motion estimation for the frame further includes:
- means for calculating a motion vector (v′,h′), wherein the motion vector (v′,h′) is a motion vector in a block B({right arrow over (X)}) having a smallest summed absolute difference (SAD) in a search window, and wherein the summed absolute difference for a vector {right arrow over (V)} in a frame n is defined as:
- SAD
-
- (
- V
- →
- ,
- X
- →
- ,
- n
- )
- =
- ∑
- x
- →
- ∈
- B
-
- (
- X
- →
- )
-
-
-
- f
-
- (
- x
- →
- ,
- n
- )
- -
- f
-
- (
- x
- →
- -
- V
- →
- ,
- n
- -
- 1
- )
-
- where ƒ({right arrow over (x)},n) is a pixel value at location {right arrow over (x)}.
Dependencies are inferred from the claim text.