Patent EP0586225A2 successfully refreshed from Google Patents.
EP0586225A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Orthogonal transform coding apparatus and decoding apparatus
Assignee: Victor Company of Japan Ltd
•
Filing: 1993-08-31
•
Granted: —
•
Expires: 2013-08-31
Abstract
Abstract Image signals are orthogonal-transformed (DCTed) in mutually different dimensions (DMs) to obtain transform coefficients (TC) for each DM, which are then compared mutually to select TC of one DM based on the comparison. Or else, such TC of one DM are selected based on the image signals in a specific DM and the selected TC are quantized and variable-length coded to output coded signals. In another way, prediction error (PE) signals obtained by predictive coding (PC) are DCTed in mutually different DMs to obtain TC for each DM; the TC of one DM are selected based on the PE signals in a specific DM, and then quantized and coded. Or else, the TC obtained for each DM are quantized and then compared mutually. The quantized signals of one DM are selected based on the comparison and then coded. Or else, the TC obtained for each DM are quantized and coded, and coded signals of one DM are selected based on the comparison. The coded signals are transmitted together with mode information (MI) indicating which DM the selected TC are transformed in. The coded signals are decoded, and then inversely quantized (IQed). The IQed signals are inversely DCTed in the DM indicated by the MI.
Inventors
- 👤 Kenji Sugiyama
- 👤 Hiroya Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:16
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/48; H04N19/10; H04N19/102; H04N19/12; H04N19/122; H04N19/124; H04N19/129; H04N19/134; H04N19/136; H04N19/14; H04N19/146; H04N19/149; H04N19/169; H04N19/17; H04N19/176; H04N19/60; H04N19/61; H04N19/13; H04N19/152; H04N19/30; H04N19/90; H04N19/91
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
78 words
An image signal coding apparatus comprising: means for orthogonal-transforming image signals to be coded in different dimensions to obtain transform coefficients for each mutually different transform dimension; means for detecting a status of the image signals in a predetermined dimension; means for selecting the transform coefficients of one of the transform dimensions on the basis of the detected result; means for quantizing the selected transform coefficients; and means for coding the quantized signals to output the coded signals.
Claim 2
Dependent Claim
32 words
The image signal coding apparatus of claim 1, wherein said detecting means comprises means for detecting an activity of the image signals for each dimension, and means comparing the detected activities mutually.
Claim 3
Dependent Claim
48 words
The image signal coding apparatus of claim 2, wherein said comparing means further comprises means for applying a weight to each transform coefficient according to frequency for each dimension, and said detecting means detects the activity of the image signals on the basis of the weighted transform coefficients.
Claim 4
Dependent Claim
60 words
The image signal coding apparatus of claim 1, wherein said detecting means comprises: means for detecting a change rate of the image signals in the predetermined dimension; means for detecting an activity of the image signals; and means for detecting the status of the image signals on the basis of comparison between the detected change rate and the detected activity.
Claim 5
Dependent Claim
94 words
An image signal coding apparatus comprising: means for forming prediction error signals by subtracting prediction signals from image signals to be coded, respectively; means for orthogonal-transforming the prediction error signals in mutually different dimensions to obtain transform coefficients for each different transform dimension; means for detecting a status of the prediction error signals in a predetermined dimension; means for selecting the transform coefficients of one of the dimensions on the basis of the detected result; means for quantizing the selected transform coefficients; and means for coding the quantized signals to output the coded signals.
Claim 6
Dependent Claim
63 words
The image signal coding apparatus of claim 5, wherein said detecting means comprises: means for detecting a change rate of the prediction error signals in the predetermined dimension; means for detecting an activity of the prediction error signals; and means for detecting the status of the prediction error signals on the basis of comparison between the detected change rate and the detected activity.
Claim 7
Dependent Claim
125 words
The image coding apparatus of claim 5, wherein said forming means comprises: means for inversely quantizing a quantized output of first image signals inputted a predetermined time before the image signals to be coded are inputted; means for inversely orthogonal-transforming the output of said inversely quantizing means in a predetermined dimension; means for selecting any one of the outputs of said inversely quantizing means and said inversely orthogonal-transforming means; means for inversely orthogonal-transforming the selected output in a dimension different from the predetermined dimension, to decode the prediction error signals of the first image signals; and means for forming the prediction signals by adding second image signals inputted a predetermined time before the first image signals are inputted, to the decoded prediction error signals, respectively.
Claim 8
Dependent Claim
74 words
An image signal coding apparatus comprising: means for orthogonal-transforming image signals in mutually different dimensions to obtain transform coefficients for each different transform dimension; means for quantizing the transformed coefficients for each dimension; means for comparing the quantized signals for each dimension; means for selecting the quantized signals of one of the transform dimensions on the basis of the compared result; and means for coding the selected quantized signals to output the coded signals.
Claim 9
Dependent Claim
31 words
The image coding apparatus of claim 8, wherein said comparing means comprises means for detecting an activity of the image signals for each quantized output, to compare the detected activities mutually.
Claim 10
Dependent Claim
77 words
An image coding apparatus comprising: means for orthogonal-transforming image signals to be coded in mutually different dimensions to obtain transform coefficients for each different transform dimension; means for quantizing the transformed coefficients for each dimension; means for coding the quantized signals for each dimension; means for comparing a coded quantity of the coded signals for each dimension; and means for selecting the coded signals of one of the transform dimensions on the basis of the compared result.
Claim 11
Dependent Claim
112 words
An image signal decoding apparatus for decoding coded image signals obtained by orthogonal-transforming image signals in mutually different dimensions, selecting transformed coefficients of one dimension from the transformed coefficients obtained in the different dimensions according to a status of the image signals in a predetermined dimension, quantizing the selected transformed coefficients, coding the quantized signals, the coded image signals being transmitted together with mode information indicating which dimension the selected coefficients have been transformed in, which comprises: means for decoding the coded signals; means for inversely quantizing the decoded signals; and means for inversely orthogonal-transforming the inversely quantized signals in the dimension indicated by the mode information to obtain reproduced image signals.
Claim 12
Dependent Claim
133 words
An image signal decoding apparatus for decoding coded image signals obtained by orthogonal-transforming prediction error signals obtained by predictive coding in mutually different dimensions, selecting transformed coefficients of one dimension from the transformed coefficients obtained in the different dimensions according to a status of the prediction error signals, quantizing the selected transformed coefficients, coding the quantized signals, the coded image signals being transmitted together with mode information indicating which dimension the selected coefficients have been transformed in, which comprises: means for decoding the coded signals; means for inversely quantizing the decoded signals; means for inversely orthogonal-transforming the inversely quantized signals in the dimension indicated by the mode information to obtain reproduced prediction error signals; and means for reproducing the image signals by adding already-reproduced image signals to the reproduced prediction error signals, respectively.
Claim 13
Independent Claim
72 words
A method of coding image signals, comprising the steps of: orthogonal-transforming image signals to be coded in different dimensions to obtain transform coefficients for each mutually different transform dimension; detecting a status of the image signals in a predetermined dimension; selecting the transform coefficients of one of the transform dimensions on the basis of the detected result; quantizing the selected transform coefficients; and coding the quantized signals to output the coded signals.
Claim 14
Independent Claim
86 words
A method of coding image signals, comprising the steps of: forming prediction error signals by subtracting prediction signals from image signals to be coded, respectively; orthogonal-transforming the prediction error signals in mutually different dimensions to obtain transform coefficients for each different transform dimension; detecting a status of the prediction error signals in a predetermined dimension; selecting the transform coefficients of one of the dimensions on the basis of the detected result; quantizing the selected transform coefficients; and coding the quantized signals to output the coded signals.
Claim 15
Independent Claim
70 words
A method of coding image signals, comprising the steps of: orthogonal-transforming image signals to be coded in mutually different dimensions to obtain transform coefficients for each different transform dimension; quantizing the transformed coefficients for each dimension; coding the quantized signals for each dimension; comparing coded quantity of coded signals for each dimension; and selecting the coded signals of one of the transform dimensions on the basis of the compared result.
Claim 16
Independent Claim
106 words
A method of decoding coded image signals obtained by orthogonal-transforming image signals in mutually different dimensions, selecting the transformed coefficients of one dimension from the transformed coefficients obtained in the different dimensions according to status of the image signals in a predetermined dimension, quantizing the selected transformed coefficients, coding the quantized signals, the coded image signals being transmitted together with mode information indicating which dimension the selected coefficients have been transformed in, which comprises the steps of: decoding the coded signals; inversely quantizing the decoded signals; and inversely orthogonal-transforming the inversely quantized signals in the dimension indicated by the mode information to obtain reproduced image signals.
Claim 17
Independent Claim
124 words
A method of decoding coded image signals obtained by orthogonal-transforming prediction error signals obtained by predictive coding in mutually different dimensions, selecting the transformed coefficients of one dimension from the transformed coefficients obtained in the different dimensions according to status of the prediction error signals, quantizing the selected transformed coefficients, coding the quantized signals, the coded image signals being transmitted together with mode information indicating which dimension the selected coefficients have been transformed in, which comprises the steps of: decoding coded signals; inversely quantizing the decoded signals; inversely orthogonal-transforming the inversely quantized signals in the dimension indicated by the mode information to obtain reproduced prediction error signals; and reproducing the image signals by adding already-reproduced image signals to the reproduced prediction error signals, respectively.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.