Patent US5404000A successfully refreshed from Google Patents.
Patent EP0727910A2 successfully refreshed from Google Patents.
EP0727910A2
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Temporal-spatial error concealment apparatus and method for video signal processors
Assignee: Vantiva SA
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Filing: 1996-02-05
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Granted: —
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Expires: 2016-02-05
Abstract
Abstract A video decompression system includes block error concealment means (22,41,42) for generating substitute data for lost blocks of pixel data. An interpolator generates both spatially (44) and temporally (40) interpolated or predicted blocks of data for concealing a lost block. Pixel data in the respective blocks of spatially and interpolated data are transformed (43) to coefficients representing frequency spectra. A substitute block of coefficients is assembled from coefficients from both the transformed blocks, according to a predetermined criteria The substitute block is transformed back to the spatial domain for substitution of lost pixel values.
Inventors
- 👤 Max Chien
- 👤 Wilson Kwok
- 👤 Huifang Sun
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:32
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/85; H04N19/89; H04N19/895
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
222 words
Apparatus for generating substitute blocks of pixel data for missing or corrupted blocks of pixel data, characterized by: a source (20) of pixel data representing respective images and a source of error data indicating blocks of said pixel data that may be missing or corrupted (hereinafter designated bad pixel data); a controller (40), responsive to said error data, for accessing from said source, pixel data located spatially adjacent to a block of bad pixel data, and a temporally predicted block of data corresponding to said block of bad pixel data; an interpolator (44) operative upon said pixel data located spatially adjacent to a block of bad pixel data, for generating a spatially interpolated block of pixel data; transform circuitry (43) for providing a matrix of transform coefficients representing said spatially interpolated block of pixel data, and for generating a further matrix of transform coefficients representing said temporally predicted block of data; a selector (926), responsive to a predetermined criteria, for forming a still further matrix of transform coefficients, by selecting respective coefficients in said still further matrix exclusively from said matrix of transform coefficients representing said spatially interpolated block, or from said further matrix of transform coefficients in accordance with said criteria; and inverse transform circuitry (928) for inverse transforming said still further matrix to generate said substitute block of pixel data.
Claim 2
Dependent Claim
59 words
The apparatus set forth in claim 1 characterized in that said interpolator includes digital signal processing apparatus operative upon said pixel data located spatially adjacent to a block of bad pixel data for detecting a direction of a dominant image gradient within an image area represented by pixel data located spatially adjacent to a block of bad pixel data.
Claim 3
Dependent Claim
73 words
The apparatus set forth in claim 2 characterized in that said said selector for forming a still further matrix, generates a matrix of transform coefficients including transform coefficients which represent directional image information corresponding to said dominant image gradient from said matrix of transform coefficients representing said spatially interpolated block, and selects transform coefficients from said further matrix of coefficients exclusive of coefficients which represent directional information corresponding to said dominant edge gradient.
Claim 4
Dependent Claim
110 words
The apparatus set forth in claim 1 characterized in that said said selector comprises; circuitry for determining respective differences between corresponding transform coefficients in said matrix of transform coefficients representing said spatially interpolated block of pixel data, and in said further matrix of transform coefficients; a comparator for comparing respective differences to a predetermined variable "e"; and wherein said selector selects a corresponding coefficient from said matrix of transform coefficients representing said spatially interpolated block of pixel data, when the corresponding difference is less than said variable "e", and selects a corresponding coefficient from said further matrix of transform coefficients when the corresponding difference is greater than the variable "e".
Claim 5
Dependent Claim
29 words
The apparatus set forth in claim 4 characterized in that said said selector further includes means for generating said variable "e" from image information located adjacent said bad data.
Claim 6
Dependent Claim
109 words
The apparatus set forth in claim 4 further characterized by: apparatus responsive to data representing image information of image areas adjacent said block of bad pixel data, for determining a measure, r, of correlation of image features in said image areas adjacent said block of bad pixel data; a source of threshold value TH1; a comparator for comparing said correlation measure r against the threshold value TH1 and conditioning said selector to select coefficients only from said further matrix if the correlation measure, r, is greater than TH1, and conditioning said selector to select coefficients according to said predetermined criteria if the correlation measure, r is less than TH1.
Claim 7
Dependent Claim
92 words
The apparatus set forth in claim 6 further characterized by: a source of a further threshold value TH2 where TH2 is less than TH1; and wherein said comparator is arranged to compare said correlation measure, r, against said further threshold value TH2, and to condition said selector to select coefficients only from said matrix of transform coefficients representing said spatially interpolated block of pixel data if the correlation measure, r, is less than TH2, and conditioning said selector to select coefficients according to said predetermined criteria if TH2 < r < TH1
Claim 8
Dependent Claim
124 words
The apparatus set forth in claim 1 further characterized by; apparatus responsive to data representing image information of image areas adjacent said block of bad pixel data, for determining a measure, r, of correlation of image features in said image areas adjacent said block of bad pixel data; a source of threshold value TH1; means for producing a block of substitute pixel data; a comparator for comparing said correlation measure r against the threshold value TH1 and conditioning said means for producing a block of substitute pixel data to provide said temporally predicted block of data, if the correlation measure, r, is greater than TH1, and to provide a block of data from said selector if the correlation measure, r is less than TH1.
Claim 9
Dependent Claim
88 words
The apparatus set forth in claim 8 further characterized by; a source of a threshold value TH2 where TH2 is less than TH1; and wherein said comparator is arranged for comparing said correlation measure, r, against said further threshold value TH2, and conditioning said means for producing a block of substitute pixel data to provide said spatially interpolated block of pixel data if the correlation measure, r, is less than TH2, and to provide a block of data from said selector if TH2 < r < TH1 ;
Claim 10
Dependent Claim
63 words
The apparatus set forth in claim 8 characterized in that said said apparatus responsive to data representing image information of image areas adjacent said block of bad pixel data, for determining a measure, r, of correlation of image features, comprises: apparatus for determining at least the relative correlation of image gradients in blocks of pixel data adjacent said block of bad pixel data.
Claim 11
Dependent Claim
91 words
The apparatus set forth in claim 10 characterized in that said said apparatus responsive to data representing image information of image areas adjacent said block of bad pixel data, for determining a measure, r, of correlation of image features, further comprises: apparatus for determining the relative correlation of image motion in blocks of pixel data adjacent said block of bad pixel data; and apparatus for providing the weighted sum of values representing said relative correlation of image motion and said relative correlation of image gradients to generate said correlation measure, r.
Claim 12
Dependent Claim
109 words
The apparatus set forth in claim 11 characterized in that said said apparatus responsive to data representing image information of image areas adjacent said block of bad pixel data, for determining a measure, r, of correlation of image features, further comprises: means for determining a temporal correlation measure between a block adjacent said block of bad pixel data and a block corresponding to a predicted block of a block adjacent said block of bad pixel data; and apparatus for providing the weighted sum of values representing said relative correlation of image motion, said relative correlation of image gradients and said temporal correlation measure, to generate said correlation measure, r.
Claim 13
Dependent Claim
45 words
The apparatus set forth in claim 11 characterized in that said said apparatus for determining the relative correlation of image motion includes apparatus for calculating the relative correlation of motion vectors associated with blocks of compressed video data adjacent said block of bad pixel data.
Claim 14
Independent Claim
165 words
A method for generating a block of pixel data for a missing or corrupt block of pixel data (hereafter bad block), characterized by; providing blocks of pixel data and an error signal indicating which of said blocks are bad blocks; determining a dominant image gradient in blocks of pixels adjacent a bad block; spatially interpolating, in accordance with said dominant image gradient, a substitute block of data for said bad block in response to said error signal; temporally predicting a substitute block of data for said bad block in response to said error signal; converting the spatially interpolated substitute block to a block of transform coefficients, TC1, representing frequency spectra; converting the temporally predicted substitute block to a block of transform coefficients, TC2, representing frequency spectra; forming a further block of coefficients by selecting respective coefficients from said blocks of transform coefficients TC1 and TC2 according to a predetermined criteria; inverse transforming said further block of coefficients to produce a substitute block of pixel data.
Claim 15
Dependent Claim
67 words
The method set forth in Claim 14, characterized by determining a dominant image gradient in blocks of pixels adjacent a bad block, and spatially interpolating in accordance with said dominant image gradient; wherein said step of selecting comprises: selecting from said block of transform coefficients TC1, only coefficients representing image information along the dominant gradient; and selecting from the block of transform coefficients TC2, the remaining coefficients.
Claim 16
Dependent Claim
70 words
The method set forth in claim 14 characterized in that said the step of selecting comprises: providing an error value "e"; determining differences between corresponding coefficients in the blocks of transform coefficients TC1 and TC2; and if the respective difference is less than the error value "e", selecting the coefficient from the block of transform coefficients TC1 , else selecting the respective coefficient from the block of transform coefficients TC2.
Claim 17
Dependent Claim
73 words
The method set forth in claim 16 characterized in that said the step of providing the value "e", comprises: providing a block of data adjacent the bad block, and a temporally predicted block corresponding to said block of data adjacent said bad block; determining differences between corresponding data in said temporally predicted block and the corresponding block; and statistically analyzing the differences and generating the value "e" from a statistic of the differences.
References Cited (Backward Citations)
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