EP0679032A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Image encoding and decoding method and apparatus using edge systhesis and inverse wavelet transform
Assignee: Oki Electric Industry Co Ltd
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Filing: 1995-04-20
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Granted: —
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Expires: 2015-04-20
Abstract
Abstract A digitized image is encoded by detecting edges in the image, encoding the position and sharpness of the detected edges, filtering the image by a low-pass filter to generate a low-frequency image, and encoding the low-frequency image. A digitized image encoded in this way is reconstructed by generating a horizontal edge image and a vertical edge image from the encoded edge position and sharpness information, synthesizing a pair of high-frequency images by filtering the horizontal and vertical edge images with an edge synthesis filter, decoding the low-frequency image, and performing an inverse wavelet transform on the decoded low-frequency image and the high-frequency images.
Inventors
- 👤 Shiyu C/O Oki Electric Industry Co. Ltd. Go
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 20:34
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/20; H; H04; H04N; H04N19/00; H04N19/10; H04N19/102; H04N19/117; H04N19/134; H04N19/136; H04N19/14; H04N19/50; H04N19/503; H04N19/51; H04N19/53; H04N19/60; H04N19/61; H04N19/63; H04N19/635; H04N19/85; H04N19/20; H04N19/30
Claims Analysis
Total Claims: 106
Claim 1
Independent Claim
153 words
A method of encoding and decoding a digitized image consisting of pixel values, comprising the steps of: detecting sharpness of edges in said digitized image; encoding position and sharpness values of edge points having sharpness values exceeding a certain threshold, thereby generating edge information; filtering said digitized image by a low-pass filter, thereby generating a low-frequency image; encoding said low-frequency image, thereby generating low-frequency information; sending said edge information and said low-frequency information to an input/output device (27); receiving said edge information and said low-frequency information from said input/output device (27); generating a horizontal edge image and a vertical edge image from said edge information; synthesizing a pairof high-frequency images by filtering said horizontal edge image and said vertical edge image with an edge synthesis filter; decoding said low-frequency information, thereby obtaining a decoded low-frequency image; and performing an inverse wavelet transform on said decoded low-frequency image and said pair of high-frequency images.
Claim 2
Independent Claim
153 words
A method of encoding and decoding a digitized image consisting of pixel values, comprising the steps of: detecting sharpness of edges in said digitized image; encoding position and sharpness values of edge points having sharpness values exceeding a certain threshold, thereby generating edge information; filtering said digitized image by a low-pass filter, thereby generating a low-frequency image; encoding said low-frequency image, thereby generating low-frequency information; sending said edge information and said low-frequency information to an input/output device (27); receiving said edge information and said low-frequency information from said input/output device (27); generating a horizontal edge image and a vertical edge image from said edge information; synthesizing a pairof high-frequency images by filtering said horizontal edge image and said vertical edge image with an edge synthesis filter; decoding said low-frequency information, thereby obtaining a decoded low-frequency image; and performing an inverse wavelet transform on said decoded low-frequency image and said pair of high-frequency images.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein detecting sharpness of edges comprises: finding differences between said pixel values; and taking differences of said differences.
Claim 4
Dependent Claim
12 words
The method of claim 1, wherein encoding said low-frequency image comprises down-sampling.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein said digitized image comprises successive frames, and encoding position and sharpness values comprises motion estimation.
Claim 6
Dependent Claim
12 words
The method of claim 1, wherein said low-pass filter has even symmetry.
Claim 7
Dependent Claim
49 words
The method of claim 1, wherein filtering said digitized image comprises filtering by a series of low-pass filters having different cut-off frequencies, thereby generating a series of images with different resolutions, including at least said digitized image as a highest-resolution image and said low-frequency image as a lowest-resolution image.
Claim 8
Dependent Claim
46 words
The method of claim 6, wherein detecting sharpness of edges comprises: detecting sharpness of edges in at least two images among said series of images, excluding said low-frequency image; and selecting one of said at least two images for encoding of said position and sharpness values.
Claim 9
Dependent Claim
29 words
The method of claim 6, wherein detecting sharpness of edges comprises: selecting one image among said series of images; and detecting sharpness of edges in the image thus selected.
Claim 10
Dependent Claim
24 words
The method of claim 1, wherein said edge synthesis filter has coefficients that are generated by filtering a standard edge by a high-pass filter.
Claim 11
Dependent Claim
40 words
The method of claim 9, wherein said standard edge consists of a first part and a second part, with pixel values changing at one constant rate in said first part and at a different constant rate in said second part.
Claim 12
Dependent Claim
77 words
The method of claim 9, wherein: said step of synthesizing comprises filtering said horizontal edge image with at least two edge synthesis filters and filtering said vertical edge image with said edge synthesis filters, thereby synthesizing at least two pairs of high-frequency images; said inverse wavelet transform is performed on all said pairs of high-frequency images thus synthesized; and said edge synthesis filters are obtained by filtering said standard edge with high-pass filters having different cut-off frequencies.
Claim 13
Dependent Claim
12 words
The method of claim 9, wherein said high-pass filter has even symmetry.
Claim 14
Dependent Claim
12 words
The method of claim 9, wherein said high-pass filter has odd symmetry.
Claim 15
Dependent Claim
60 words
The method of claim 13, wherein said step of synthesizing comprises: taking differences between consecutive coefficients of said edge synthesis filter, thereby generating a differential edge synthesis filter; filtering said horizontal edge image and said vertical edge image by said differential edge synthesis filter, thereby generating a pair of differential high-frequency images; and accumulating values in said differential high-frequency images.
Claim 16
Independent Claim
87 words
A method of encoding a digitized image consisting of pixels having pixel values, comprising the steps of: filtering said digitized image by a low-pass filter, thereby generating a low-frequency image; down-sampling said low-frequency image, thereby generating a reduced image smaller in size than said digitized image; encoding said reduced image, thereby generating low-frequency information; generating an edge image by detecting edges in said digitized image; encoding said edge image, thereby generating edge information; and sending said edge information and said low-frequency information to an input/output device (27).
Claim 17
Independent Claim
87 words
A method of encoding a digitized image consisting of pixels having pixel values, comprising the steps of: filtering said digitized image by a low-pass filter, thereby generating a low-frequency image; down-sampling said low-frequency image, thereby generating a reduced image smaller in size than said digitized image; encoding said reduced image, thereby generating low-frequency information; generating an edge image by detecting edges in said digitized image; encoding said edge image, thereby generating edge information; and sending said edge information and said low-frequency information to an input/output device (27).
Claim 18
Dependent Claim
12 words
The method of claim 15, wherein said low-pass filter has even symmetry.
Claim 19
Dependent Claim
14 words
The method of claim 15, wherein said low-pass filter satisfies an exact reconstruction condition.
Claim 20
Dependent Claim
23 words
The method of claim 15, wherein detecting edges comprises detecting variations in rate of change of said pixel values from pixel to pixel.
Claim 21
Dependent Claim
36 words
The method of claim 15, wherein generating an edge image comprises: detecting edges in a horizontal direction, thereby generating a horizontal edge image; and detecting edges in a vertical direction, thereby generating a vertical edge image.
Claim 22
Dependent Claim
118 words
The method of claim 15, said method being applied to successive frames of a moving image, wherein the step of encoding said edge image comprises: reading a previous edge image, pertaining to a previous frame, from a first memory (72); generating edge motion vectors by detecting motion of said edge image with respect to said previous edge image; encoding said edge motion vectors, thereby generating edge motion information as part of said edge information; generating an edge difference image by detecting differences between said edge image and said previous edge image, over and above said motion of said edge image; and encoding said edge difference image, thereby generating edge difference information as another part of said edge information.
Claim 23
Dependent Claim
66 words
The method of claim 20, wherein encoding said edge image comprises the further steps of: decoding said edge difference information, thereby generating a decoded edge difference image; adding said decoded edge difference image to said previous edge image to generate a new edge image; and storing said new edge image in said first memory (72), for use as a previous edge image in a subsequent frame.
Claim 24
Dependent Claim
107 words
The method of claim 20, wherein the step of encoding said reduced image comprises: reading a previous reduced image, pertaining to said previous frame, from a second memory (76); generating low-frequency motion vectors by detecting motion of said reduced image with respect to said previous reduced image; encoding said low-frequency motion vectors, thereby generating low-frequency motion information as part of said low-frequency information; generating a reduced difference image by detecting differences between said reduced image and said previous reduced image, over and above said motion of said reduced image; and encoding said reduced difference image, thereby generating low-frequency difference information as another part of said low-frequency information.
Claim 25
Dependent Claim
66 words
The method of claim 22, wherein encoding said reduced image comprises the further steps of: decoding said low-frequency difference information, thereby generating a decoded reduced difference image; adding said decoded reduced difference image to said previous reduced image to generate a new reduced image; and storing said new reduced image in said second memory (76), for use as a previous reduced image in a subsequent frame.
Claim 26
Dependent Claim
27 words
The method of claim 22, wherein generating edge motion vectors comprises using said low-frequency motion vectors to select a range of search for said edge motion vectors.
Claim 27
Dependent Claim
27 words
The method of claim 22, wherein generating low-frequency motion vectors comprises using said edge motion vectors to select a range of search for said low-frequency motion vectors.
Claim 28
Independent Claim
116 words
A method of reconstructing a digitized image from encoded edge information and low-frequency information, comprising the steps of: generating a horizontal edge image and a vertical edge image by decoding said edge information; synthesizing a pair of high-frequency images by filtering said horizontal edge image horizontally with an edge synthesis filter, and filtering said vertical edge image vertically with said edge synthesis filter; generating a reduced image by decoding said low-frequency information; up-sampling said reduced image, thereby generating a low-frequency image equal in size to said high-frequency images; performing an inverse wavelet transform on said high-frequency images and said low-frequency image, thereby obtaining said digitized image; and sending said digitized image to an input/output device (37).
Claim 29
Independent Claim
116 words
A method of reconstructing a digitized image from encoded edge information and low-frequency information, comprising the steps of: generating a horizontal edge image and a vertical edge image by decoding said edge information; synthesizing a pair of high-frequency images by filtering said horizontal edge image horizontally with an edge synthesis filter, and filtering said vertical edge image vertically with said edge synthesis filter; generating a reduced image by decoding said low-frequency information; up-sampling said reduced image, thereby generating a low-frequency image equal in size to said high-frequency images; performing an inverse wavelet transform on said high-frequency images and said low-frequency image, thereby obtaining said digitized image; and sending said digitized image to an input/output device (37).
Claim 30
Dependent Claim
29 words
The method of claim 26, wherein said edge synthesis filter has coefficients that are generated by filtering a standard edge, having just one sharp variation, by a high-pass filter.
Claim 31
Dependent Claim
40 words
The method of claim 27, wherein said standard edge consists of a first part and a second part, with pixel values changing at one constant rate in said first part and at a different constant rate in said second part.
Claim 32
Dependent Claim
27 words
The method of claim 27, wherein the step of performing an inverse wavelet transform comprises filtering said high-frequency images by a conjugate filter of said high-pass filter.
Claim 33
Dependent Claim
14 words
The method of claim 27, wherein said high-pass filter satisfies an exact reconstruction condition.
Claim 34
Dependent Claim
12 words
The method of claim 27, wherein said high-pass filter has even symmetry.
Claim 35
Dependent Claim
12 words
The method of claim 27, wherein said high-pass filter has odd symmetry.
Claim 36
Dependent Claim
100 words
The method of claim 32, wherein filtering with said edge synthesis filter is performed by using a differential edge synthesis filter having coefficients equal to differences between consecutive coefficients of said edge synthesis filter, and said step of synthesizing a pair of high-frequency images comprises: filtering said horizontal edge image horizontally by said differential edge synthesis filter, thereby synthesizing a horizontal differential high-frequency image; accumulating values in said horizontal differential high-frequency image; filtering said vertical edge image vertically by said differential edge synthesis filter, thereby synthesizing a vertical differential high-frequency image; and accumulating values in said vertical differential high-frequency image.
Claim 37
Dependent Claim
115 words
The method of claim 26, said method being applied to successive frames of an encoded moving image, wherein said edge information comprises edge difference information and edge motion information, and decoding said edge information comprises: decoding said edge difference information to obtain an edge difference image; decoding said edge motion information to obtain edge motion vectors; reading a previous edge image, pertaining to a previous frame, from a third memory (85); adding said edge difference image to said previous edge image according to said edge motion vectors, to obtain a new edge image; and storing said new edge image in said third memory (85) for use as a previous edge image of a subsequent frame.
Claim 38
Dependent Claim
101 words
The method of claim 34, wherein said low-frequency information comprises low-frequency difference information and low-frequency motion information, and decoding said low-frequency information comprises: decoding said low-frequency difference information to obtain a reduced difference image; decoding said low-frequency motion information to obtain low-frequency motion vectors; reading a previous reduced image, pertaining to said previous frame, from a fourth memory (87); adding said reduced difference image to said previous reduced image according to said low-frequency motion vectors, to obtain said reduced image; and storing said reduced image in said fourth memory (87) for use as a previous reduced image of a subsequent frame.
Claim 39
Independent Claim
124 words
A method of encoding a digitized image consisting of pixels having pixel values, comprising the steps of: filtering said digitized image by a series of low-pass filters having progressively lower cut-off frequencies, thereby generating a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; down-sampling said low-frequency image, thereby generating a reduced image smaller in size than said digitized image; encoding said reduced image, thereby generating low-frequency information; generating an edge image by detecting edges in one image among said digitized image and said filtered images, excluding said low-frequency image; encoding said edge image, thereby generating edge information; and sending said edge information and said low-frequency information to an input/output device (27).
Claim 40
Independent Claim
124 words
A method of encoding a digitized image consisting of pixels having pixel values, comprising the steps of: filtering said digitized image by a series of low-pass filters having progressively lower cut-off frequencies, thereby generating a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; down-sampling said low-frequency image, thereby generating a reduced image smaller in size than said digitized image; encoding said reduced image, thereby generating low-frequency information; generating an edge image by detecting edges in one image among said digitized image and said filtered images, excluding said low-frequency image; encoding said edge image, thereby generating edge information; and sending said edge information and said low-frequency information to an input/output device (27).
Claim 41
Dependent Claim
12 words
The method of claim 36, wherein said low-pass filters have even symmetry.
Claim 42
Dependent Claim
21 words
The method of claim 36, wherein detecting edges comprises detecting variations in rate of change of intensity from pixel to pixel.
Claim 43
Dependent Claim
36 words
The method of claim 36, wherein generating an edge image comprises: detecting edges in a horizontal direction, thereby generating a horizontal edge image; and detecting edges in a vertical direction, thereby generating a vertical edge image.
Claim 44
Dependent Claim
46 words
The method of claim 36, wherein generating an edge image comprises: generating a plurality of edge images by detecting edges in a plurality of images among said digitized image and said filtered images, excluding said low-frequency image; and selecting one of said plurality of edge images.
Claim 45
Dependent Claim
33 words
The method of claim 36, wherein generating an edge image comprises: selecting one image among said digitized image and said filtered images, excluding said low-frequency image; and detecting edges in said one image.
Claim 46
Dependent Claim
118 words
The method of claim 36, said method being applied to successive frames of a moving image, wherein the step of encoding said edge image comprises: reading a previous edge image, pertaining to a previous frame, from a first memory (72); generating edge motion vectors by detecting motion of said edge image with respect to said previous edge image; encoding said edge motion vectors, thereby generating edge motion information as part of said edge information; generating an edge difference image by detecting differences between said edge image and said previous edge image, over and above said motion of said edge image; and encoding said edge difference image, thereby generating edge difference information as another part of said edge information.
Claim 47
Dependent Claim
66 words
The method of claim 42, wherein encoding said edge image comprises the further steps of: decoding said edge difference information, thereby generating a decoded edge difference image; adding said decoded edge difference image to said previous edge image to generate a new edge image; and storing said new edge image in said first memory (72), for use as a previous edge image in a subsequent frame.
Claim 48
Dependent Claim
107 words
The method of claim 42, wherein the step of encoding said reduced image comprises: reading a previous reduced image, pertaining to said previous frame, from a second memory (76); generating low-frequency motion vectors by detecting motion of said reduced image with respect to said previous reduced image; encoding said low-frequency motion vectors, thereby generating low-frequency motion information as part of said low-frequency information; generating a reduced difference image by detecting differences between said reduced image and said previous reduced image, over and above said motion of said reduced image; and encoding said reduced difference image, thereby generating low-frequency difference information as another part of said low-frequency information.
Claim 49
Dependent Claim
66 words
The method of claim 44, wherein encoding said reduced image comprises the further steps of: decoding said low-frequency difference information, thereby generating a decoded reduced difference image; adding said decoded reduced difference image to said previous reduced image to generate a new reduced image; and storing said new reduced image in said second memory (76), for use as a previous reduced image in a subsequent frame.
Claim 50
Dependent Claim
27 words
The method of claim 44, wherein generating edge motion vectors comprises using said low-frequency motion vectors to select a range of search for said edge motion vectors.
Claim 51
Dependent Claim
27 words
The method of claim 44, wherein generating low-frequency motion vectors comprises using said edge motion vectors to select a range of search for said low-frequency motion vectors.
Claim 52
Independent Claim
126 words
A method of reconstructing a digitized image from encoded edge information and low-frequency information, comprising the steps of: generating a horizontal edge image and a vertical edge image by decoding said edge information; synthesizing a series of pairs of high-frequency images by filtering said horizontal edge image horizontally with a series of edge synthesis filters, and filtering said vertical edge image vertically with said series of edge synthesis filters; generating a reduced image by decoding said low-frequency information; up-sampling said reduced image, thereby generating a low-frequency image equal in size to said high-frequency images; performing an inverse wavelet transform on said series of pairs of high-frequency images and said low-frequency image, thereby obtaining said digitized image; and sending said digitized image to an input/output device (37).
Claim 53
Independent Claim
126 words
A method of reconstructing a digitized image from encoded edge information and low-frequency information, comprising the steps of: generating a horizontal edge image and a vertical edge image by decoding said edge information; synthesizing a series of pairs of high-frequency images by filtering said horizontal edge image horizontally with a series of edge synthesis filters, and filtering said vertical edge image vertically with said series of edge synthesis filters; generating a reduced image by decoding said low-frequency information; up-sampling said reduced image, thereby generating a low-frequency image equal in size to said high-frequency images; performing an inverse wavelet transform on said series of pairs of high-frequency images and said low-frequency image, thereby obtaining said digitized image; and sending said digitized image to an input/output device (37).
Claim 54
Dependent Claim
36 words
The method of claim 48, wherein said series of edge synthesis filters is generated by filtering a standard edge, having just one sharp variation, by a corresponding series of high-pass filters with progressively decreasing cut-off frequencies.
Claim 55
Dependent Claim
40 words
The method of claim 49, wherein said standard edge consists of a first part and a second part, with pixel values changing at one constant rate in said first part and at a different constant rate in said second part.
Claim 56
Dependent Claim
31 words
The method of claim 49, wherein the step of performing an inverse wavelet transform comprises filtering said pairs of high-frequency images by respective conjugate filters of said series of high-pass filters.
Claim 57
Dependent Claim
12 words
The method of claim 49, wherein said high-pass filters have even symmetry.
Claim 58
Dependent Claim
12 words
The method of claim 49, wherein said high-pass filters have odd symmetry.
Claim 59
Dependent Claim
94 words
The method of claim 53, wherein filtering said pair of edge images by said edge synthesis filters comprises: taking differences between consecutive coefficients of said edge synthesis filters, thereby generating a series of differential edge synthesis filters; filtering said horizontal edge image horizontally by said differential edge synthesis filters, thereby synthesizing a series of differential high-frequency images; accumulating values in respective horizontal differential high-frequency images; filtering said vertical edge image vertically by said differential edge synthesis filters, thereby synthesizing a series of differential high-frequency images; and accumulating values in respective vertical differential high-frequency images.
Claim 60
Dependent Claim
115 words
The method of claim 48, said method being applied to successive frames of an encoded moving image, wherein said edge information comprises edge difference information and edge motion information, and decoding said edge information comprises: decoding said edge difference information to obtain an edge difference image; decoding said edge motion information to obtain edge motion vectors; reading a previous edge image, pertaining to a previous frame, from a third memory (85); adding said edge difference image to said previous edge image according to said edge motion vectors, to obtain a new edge image; and storing said new edge image in said third memory (85) for use as a previous edge image of a subsequent frame.
Claim 61
Dependent Claim
101 words
The method of claim 55, wherein said low-frequency information comprises low-frequency difference information and low-frequency motion information, and decoding said low-frequency information comprises: decoding said low-frequency difference information to obtain a reduced difference image; decoding said low-frequency motion information to obtain low-frequency motion vectors; reading a previous reduced image, pertaining to said previous frame, from a fourth memory (87); adding said reduced difference image to said previous reduced image according to said low-frequency motion vectors, to obtain said reduced image; and storing said reduced image in said fourth memory (87) for use as a previous reduced image of a subsequent frame.
Claim 62
Dependent Claim
113 words
A digital image encoder for encoding a digitized image consisting of pixels having pixel values, comprising: an input terminal (10) for receiving said digitized image; a smoothing filter (20) coupled to said input terminal (10), for filtering said digitized image to generate a low-frequency image; a down sampler (23) coupled to said smoothing filter (20), for down-sampling said low-frequency image to generate a reduced image; an edge detector (21) coupled to said input terminal (10), for generating an edge image by detecting edge points in said digitized image; and an encoding section (22) coupled to said edge detector (21) and said down sampler (23), for encoding said edge image and said reduced image.
Claim 63
Dependent Claim
113 words
A digital image encoder for encoding a digitized image consisting of pixels having pixel values, comprising: an input terminal (10) for receiving said digitized image; a smoothing filter (20) coupled to said input terminal (10), for filtering said digitized image to generate a low-frequency image; a down sampler (23) coupled to said smoothing filter (20), for down-sampling said low-frequency image to generate a reduced image; an edge detector (21) coupled to said input terminal (10), for generating an edge image by detecting edge points in said digitized image; and an encoding section (22) coupled to said edge detector (21) and said down sampler (23), for encoding said edge image and said reduced image.
Claim 64
Dependent Claim
26 words
The digital image encoder of claim 57, wherein said edge detector (21) detects variations in rate of change of said pixel values from pixel to pixel.
Claim 65
Dependent Claim
19 words
The digital image encoder of claim 57, wherein said smoothing filter (20) is a low-pass filter with even symmetry.
Claim 66
Dependent Claim
16 words
The digital image encoder of claim 58, wherein said low-pass filter satisfies an exact reconstruction condition.
Claim 67
Dependent Claim
173 words
Adigital image encoder for encoding a digitized image consisting of pixels having pixel values, comprising: an input terminal (10) for receiving said digitized image; a series of smoothing filters (20-m) coupled to said input terminal (10), having progressively lower cut-off frequencies, for filtering said digitized image to generate a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; a down sampler (23) coupled to a last one of said smoothing filters (20-n) in said series, for down-sampling said low-frequency image to generate a reduced image; a plurality of edge detectors (21-m) for generating respective edge images by detecting edge points in a plurality of images among said digitized image and said filtered images, excluding said low-frequency image; a selector (50) coupled to said plurality of edge detectors (21-m), for selecting an edge image from among said edge images; and an encoding section coupled to said selector (50) and said down sampler (23), for encoding said edge image and said reduced image.
Claim 68
Dependent Claim
173 words
Adigital image encoder for encoding a digitized image consisting of pixels having pixel values, comprising: an input terminal (10) for receiving said digitized image; a series of smoothing filters (20-m) coupled to said input terminal (10), having progressively lower cut-off frequencies, for filtering said digitized image to generate a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; a down sampler (23) coupled to a last one of said smoothing filters (20-n) in said series, for down-sampling said low-frequency image to generate a reduced image; a plurality of edge detectors (21-m) for generating respective edge images by detecting edge points in a plurality of images among said digitized image and said filtered images, excluding said low-frequency image; a selector (50) coupled to said plurality of edge detectors (21-m), for selecting an edge image from among said edge images; and an encoding section coupled to said selector (50) and said down sampler (23), for encoding said edge image and said reduced image.
Claim 69
Dependent Claim
21 words
The digital image encoder of claim 61, wherein said smoothing filters (20-m) are coupled in cascade to said input terminal (10).
Claim 70
Dependent Claim
18 words
The digital image encoder of claim 61, wherein said smoothing filters (20-m) are low-pass filters with even symmetry.
Claim 71
Dependent Claim
26 words
The digital image encoder of claim 61, wherein said edge detectors (21-m) detect variations in rate of change of said pixel values from pixel to pixel.
Claim 72
Dependent Claim
78 words
The digital image encoder of claim 61, wherein said encoding section (22) comprises: an edge image encoder (24) coupled to said selector (50), for encoding said edge image to generate edge information; a low-frequency image encoder (25) coupled to said down sampler (23), for encoding said reduced image to generate low-frequency information; and a multiplexer (26), coupled to said edge image encoder (24) and said low-frequency image encoder (25), for multiplexing said low-frequency information and said edge information.
Claim 73
Dependent Claim
178 words
The digital image encoder of claim 61, wherein said digitized image is a moving image consisting of successive frames, and said encoding section (65) comprises: a first memory (72) for storing a previous edge image, pertaining to a previous frame among said frames; a first motion estimator (66) coupled to said selector (50) and said first memory (72), for detecting motion of said edge image with respect to said previous edge image, generating edge motion vectors, detecting differences between said edge image and said previous edge image over and above said motion of said edge image, and generating an edge difference image; a second memory (76) for storing a previous reduced image, pertaining to said previous frame; and a second motion estimator (67) coupled to said down sampler (23) and said second memory (76), for detecting motion of said reduced image with respect to said previous reduced image, generating low-frequency motion vectors, detecting differences between said reduced image and said previous reduced image over and above said motion of said reduced image, and generating a reduced difference image.
Claim 74
Dependent Claim
43 words
The digital image encoder of claim 66, wherein: said first motion estimator (66) is coupled to said second motion estimator (67); and said first motion estimator (66) uses said low-frequency motion vectors to select a range of search for said edge motion vectors.
Claim 75
Dependent Claim
43 words
The digital image encoder of claim 66, wherein: said first motion estimator (66) is coupled to said second motion estimator (67); and said second motion estimator (67) uses said edge motion vectors to select a range of search for said low-frequency motion vectors.
Claim 76
Dependent Claim
271 words
The digital image encoder of claim 66, wherein said encoding section (65) also comprises: a first difference encoder (69) coupled to said first motion estimator (66), for encoding said edge difference image, thereby generating edge difference information; a first difference decoder (70) coupled to said first difference encoder (69), for decoding said edge difference information, thereby generating a decoded edge difference image; a first adder (71) for adding said decoded edge difference image to said previous edge image to generate a new edge image, and storing said new edge image in said first memory (72) for use as a previous edge image in a subsequent frame among said frames; a second difference encoder (73) coupled to said second motion estimator (67), for encoding said reduced difference image, thereby generating low-frequency difference information; a second difference decoder (74) coupled to said second difference encoder (73), for decoding said low-frequency difference information, thereby generating a decoded reduced difference image; a second adder (75) for adding said decoded reduced difference image to said previous reduced image to generate a new reduced difference image, and storing said new reduced difference image in said second memory (76) for use as a previous reduced image in said subsequent frame; a motion vector encoder (68) coupled to said first motion estimator (66) and said second motion estimator (67), for encoding said edge motion vectors and said low-frequency motion vectors to generate motion information; and a multiplexer (78) coupled to said motion vector encoder (68), said first difference encoder (69), and said second difference encoder (73), for multiplexing said motion information, said edge difference information, and said low-frequency information.
Claim 77
Dependent Claim
176 words
A digital image encoder for encoding a digitized image consisting of pixels having pixel values, comprising: an input terminal (10) for receiving said digitized image; a series of smoothing filters (20-m) coupled to said input terminal (10), having progressively lower cut-off frequencies, for filtering said digitized image to generate a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; a down sampler (23) coupled to a last one of said smoothing filters (20-n) in said series, for down-sampling said low-frequency image to generate a reduced image; a selector (52) coupled to said series of smoothing filters (20-m), for selecting an image from among said digitized image and said filtered images, excluding said low-frequency image; an edge detector (21) coupled to said selector (52), for generating an edge image by detecting edge points in the image selected by said selector (52); and an encoding section coupled to said down sampler (23) and said edge detector (21), for encoding said edge image and said reduced image.
Claim 78
Dependent Claim
176 words
A digital image encoder for encoding a digitized image consisting of pixels having pixel values, comprising: an input terminal (10) for receiving said digitized image; a series of smoothing filters (20-m) coupled to said input terminal (10), having progressively lower cut-off frequencies, for filtering said digitized image to generate a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; a down sampler (23) coupled to a last one of said smoothing filters (20-n) in said series, for down-sampling said low-frequency image to generate a reduced image; a selector (52) coupled to said series of smoothing filters (20-m), for selecting an image from among said digitized image and said filtered images, excluding said low-frequency image; an edge detector (21) coupled to said selector (52), for generating an edge image by detecting edge points in the image selected by said selector (52); and an encoding section coupled to said down sampler (23) and said edge detector (21), for encoding said edge image and said reduced image.
Claim 79
Dependent Claim
21 words
The digital image encoder of claim 70, wherein said smoothing filters (20-m) are coupled in cascade to said input terminal (10).
Claim 80
Dependent Claim
18 words
The digital image encoder of claim 70, wherein said smoothing filters (20-m) are low-pass filters with even symmetry.
Claim 81
Dependent Claim
26 words
The digital image encoder of claim 70, wherein said edge detector (21) detects variations in rate of change of said pixel values from pixel to pixel.
Claim 82
Dependent Claim
79 words
The digital image encoder of claim 70, wherein said encoding section (22) comprises: an edge image encoder (24) coupled to said edge detector (21), for encoding said edge image to generate edge information; a low-frequency image encoder (25) coupled to said down sampler (23), for encoding said reduced image to generate low-frequency information; and a multiplexer (26), coupled to said edge image encoder (24) and said low-frequency image encoder (25), for multiplexing said low-frequency information and said edge information.
Claim 83
Dependent Claim
178 words
The digital image encoder of claim 70, wherein said digitized image is a moving image consisting of successive frames, and said encoding section (65) comprises: a first memory (72) for storing a previous edge image, pertaining to a previous frame among said frames; a first motion estimator (66) coupled to said selector (50) and said first memory (72), for detecting motion of said edge image with respect to said previous edge image, generating edge motion vectors, detecting differences between said edge image and said previous edge image over and above said motion of said edge image, and generating an edge difference image; a second memory (76) for storing a previous reduced image, pertaining to said previous frame; and a second motion estimator (67) coupled to said down sampler (23) and said second memory (76), for detecting motion of said reduced image with respect to said previous reduced image, generating low-frequency motion vectors, detecting differences between said reduced image and said previous reduced image over and above said motion of said reduced image, and generating a reduced difference image.
Claim 84
Dependent Claim
43 words
The digital image encoder of claim 75, wherein: said first motion estimator (66) is coupled to said second motion estimator (67); and said first motion estimator (66) uses said low-frequency motion vectors to select a range of search for said edge motion vectors.
Claim 85
Dependent Claim
43 words
The digital image encoder of claim 75, wherein: said first motion estimator (66) is coupled to said second motion estimator (67); and said second motion estimator (67) uses said edge motion vectors to select a range of search for said low-frequency motion vectors.
Claim 86
Dependent Claim
270 words
The digital image encoder of claim 75, wherein said encoding section (22) also comprises: a first difference encoder (69) coupled to said first motion estimator (66), for encoding said edge difference image, thereby generating edge difference information; a first difference decoder (70) coupled to said first difference encoder (69), for decoding said edge difference information, thereby generating a decoded edge difference image; a first adder (71) for adding said decoded edge difference image to said previous edge image to generate a new edge image, and storing said new edge image in said first memory (72) for use as a previous edge image in a subsequent frame among said frames; a second difference encoder (73) coupled to said second motion estimator (67), for encoding said reduced difference image, thereby generating low-frequency difference information; a second difference decoder (74) coupled to said second difference encoder (73), for decoding said low-frequency difference information, thereby generating a decoded reduced difference image; an adder (75) for adding said decoded reduced difference image to said previous reduced image to generate a new reduced difference image, and storing said new reduced difference image in said second memory (76) for use as a previous reduced image in said subsequent frame; a motion vector encoder (68) coupled to said first motion estimator (66) and said second motion estimator (67), for encoding said edge motion vectors and said low-frequency motion vectors to generate motion information; and a multiplexer (78) coupled to said motion vector encoder (68), said first difference encoder (69), and said second difference encoder (73), for multiplexing said motion information, said edge difference information, and said low-frequency information.
Claim 87
Dependent Claim
142 words
A digital image decoder for reconstructing a digitized image from encoded edge information and low-frequency information, comprising: a decoding section (28) for decoding said edge information to generate a horizontal and vertical pair of edge images, and decoding said low-frequency information to generate a reduced image; an up sampler (35) coupled to said decoding section (28), for up-sampling said reduced image to generate a low-frequency image equal in size to said edge images; an edge synthesizer (34) coupled to said decoding section (28), for synthesizing a pair of high-frequency images by filtering said pair of edge images with an edge synthesis filter; and an inverse wavelet transform processor (36), coupled to said up sampler (35) and said edge synthesizer (34), for performing an inverse wavelet transform on said decoded low-frequency image and said pair of high-frequency images, thereby obtaining said digitized image.
Claim 88
Dependent Claim
142 words
A digital image decoder for reconstructing a digitized image from encoded edge information and low-frequency information, comprising: a decoding section (28) for decoding said edge information to generate a horizontal and vertical pair of edge images, and decoding said low-frequency information to generate a reduced image; an up sampler (35) coupled to said decoding section (28), for up-sampling said reduced image to generate a low-frequency image equal in size to said edge images; an edge synthesizer (34) coupled to said decoding section (28), for synthesizing a pair of high-frequency images by filtering said pair of edge images with an edge synthesis filter; and an inverse wavelet transform processor (36), coupled to said up sampler (35) and said edge synthesizer (34), for performing an inverse wavelet transform on said decoded low-frequency image and said pair of high-frequency images, thereby obtaining said digitized image.
Claim 89
Dependent Claim
27 words
The digital image decoder of claim 79, wherein said edge synthesis filter has coefficients that are generated by using a high-pass filter to filter a standard edge.
Claim 90
Dependent Claim
43 words
The digital image decoder of claim 80, wherein said standard edge consists of a first part and a second part, with pixel values that vary at one constant rate in said first part and at a different constant rate in said second part.
Claim 91
Dependent Claim
16 words
The digital image decoder of claim 80, wherein said high-pass filter satisfies a complete reconstruction condition.
Claim 92
Dependent Claim
27 words
The digital image decoder of claim 80, wherein said inverse wavelet transform processor (36) filters said pair of high-frequency images by a conjugate of said high-pass filter.
Claim 93
Dependent Claim
14 words
The digital image decoder of claim 80, wherein said high-pass filter has even symmetry.
Claim 94
Dependent Claim
14 words
The digital image decoder of claim 80, wherein said high-pass filter has odd symmetry.
Claim 95
Dependent Claim
63 words
The digital image decoder of claim 85, wherein said edge synthesizer (34) comprises: a pairof differential edge synthesizers (44, 45) forfiltering respective edge images by a filter having coefficients equal to differences between consecutive coefficients of said edge synthesis filter, thereby generating a pair of differential high-frequency image; and a pair of accumulators (46, 47) for accumulating values in respective differential high-frequency images.
Claim 96
Dependent Claim
168 words
A digital image decoder for reconstructing a digitized image from an encoded image consisting of edge information and low-frequency information, comprising: a decoding section for decoding said edge information to generate a pair of edge images, comprising a horizontal edge image and a vertical edge image, and decoding said low-frequency information to generate a reduced image; an up sampler (35), coupled to said decoding section, for up-sampling said reduced image to generate a decoded low-frequency image equal in size to said edge images; a plurality of edge synthesizers (34-m), each coupled to said edge information decoder (31), having respective edge synthesis filters, for synthesizing a series of pairs of high-frequency images by filtering said horizontal edge image horizontally and said vertical edge image vertically with said edge synthesis filters; and an inverse wavelet transform processor (36), coupled to said up sampler (35) and said plurality of edge synthesizers (34-m), for performing an inverse wavelet transform on said decoded low-frequency image and said series of pairs of high-frequency images.
Claim 97
Dependent Claim
168 words
A digital image decoder for reconstructing a digitized image from an encoded image consisting of edge information and low-frequency information, comprising: a decoding section for decoding said edge information to generate a pair of edge images, comprising a horizontal edge image and a vertical edge image, and decoding said low-frequency information to generate a reduced image; an up sampler (35), coupled to said decoding section, for up-sampling said reduced image to generate a decoded low-frequency image equal in size to said edge images; a plurality of edge synthesizers (34-m), each coupled to said edge information decoder (31), having respective edge synthesis filters, for synthesizing a series of pairs of high-frequency images by filtering said horizontal edge image horizontally and said vertical edge image vertically with said edge synthesis filters; and an inverse wavelet transform processor (36), coupled to said up sampler (35) and said plurality of edge synthesizers (34-m), for performing an inverse wavelet transform on said decoded low-frequency image and said series of pairs of high-frequency images.
Claim 98
Dependent Claim
29 words
The digital image decoder of claim 87, wherein said edge synthesis filters have coefficients generated by filtering a standard edge with respective high-pass filters having progressively decreasing cut-off frequencies.
Claim 99
Dependent Claim
43 words
The digital image decoder of claim 88, wherein said standard edge consists of a first part and a second part, with pixel values that vary at one constant rate in said first part and at a different constant rate in said second part.
Claim 100
Dependent Claim
27 words
The digital image decoder of claim 88, wherein said inverse wavelet transform processor (36) filters said pairs of high-frequency images by conjugate filters of respective high-pass filters.
Claim 101
Dependent Claim
14 words
The digital image decoder of claim 88, wherein said high-pass filters have even symmetry.
Claim 102
Dependent Claim
14 words
The digital image decoder of claim 88, wherein said high-pass filters have odd symmetry.
Claim 103
Dependent Claim
75 words
The digital image decoder of claim 92, wherein each of said edge synthesizers (34-m) separately comprises: a pair of differential edge synthesizers (44, 45) forfiltering said horizontal edge image horizontally and said vertical edge image vertically by a filter having coefficients equal to differences between consecutive coefficients of said edge synthesis filter, thereby generating a pair of differential high-frequency images; and a pair of accumulators (46, 47) for accumulating values in respective differential high-frequency images.
Claim 104
Dependent Claim
46 words
The digital image decoder of claim 87, wherein said decoding section (28) comprises: an edge information decoder (31), for generating said pair of edge images by decoding said edge information; and a low-frequency information decoder (32), for generating said reduced image by decoding said low-frequency information.
Claim 105
Dependent Claim
49 words
The digital image decoder of claim 87, wherein: said encoded image is an encoded moving image comprising successive frames; said edge information comprises edge motion information and edge difference information; said low-frequency information comprises low-frequency motion information and low-frequency difference information; and said decoding section (79) performs motion compensation.
Claim 106
Dependent Claim
247 words
The digital image decoder of claim 95, wherein said decoding section (79) comprises: a third difference decoder (81) for decoding said edge difference information to obtain an edge difference image; a motion information decoder (82) for decoding said edge motion information and said low-frequency motion information to obtain edge motion vectors and low-frequency motion vectors; a fourth difference decoder (83) for decoding said low-frequency difference information to obtain a reduced difference image; a third memory (85) for storing a previous edge image, pertaining to a previous frame among said frames; a first motion compensator (84) coupled to said third difference decoder (81), said motion information decoder (82), and said third memory (85), for adding said edge difference image to said previous edge image according to said edge motion vectors to generate a new edge image, storing said new edge image in said third memory (85) for use as a previous edge image in a subsequent frame among said frames, and generating said pair of edge images; a fourth memory (87) for storing a previous reduced image pertaining to said previous frame; and a second motion compensator (86) coupled to said motion information decoder (82), said fourth difference decoder (83), and said fourth memory (87), for adding said reduced difference image to said previous reduced image according to said low-frequency motion vectors, thereby generating said reduced image, and storing said reduced image in said fourth memory (87) for use as a previous reduced image in said subsequent frame.
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