US3716667A
Expired / Lapsed
US
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Apparatus for detecting the moving areas in a video signal
Assignee: AT&T Inc
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Filing: 1971-10-26
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Granted: 1973-02-13
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Expires: 1991-10-26
Abstract
Abstract A frame-to-frame difference signal is developed for each element-to-element difference word corresponding to a picture element in a video signal. The frame-to-frame difference signal for each picture element is combined with the same type signal for the picture element above it in the same video field and the sum is checked against a high threshold level in order to determine whether the picture element is part of a high contrast moving edge. In addition, the frame-to-frame difference signal for each picture element is combined with the frame-to-frame difference signals for all of the picture elements in a predetermined area of the picture to develop a first value whose amplitude is proportional to frame-to-frame differences caused by both movement and quantization noise. A second functional value whose amplitude is proportional to the expected quantization noise in the area of picture elements under consideration is developed in response to the element-to-element difference signals for these picture elements. The second value is subtracted from the first functional value in order to develop a third value whose amplitude is dependent on frame-to-frame differences caused by movement and is relatively insensitive to quantization noise. This third value is checked in a threshold circuit having both a hysteresis effect with respect to amplitude and an increased sensitivity due to previous recognitions of movement in the area encompassing the picture element in order to establish a second indication of movement for the picture element under consideration.
Inventors
- 👤 D Connor
- 👤 J Limb
- 👤 R Pease
- 👤 W Scholes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:41
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/144; H04N19/00; H04N19/50; H04N19/503
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
113 words
Apparatus for selecting input samples from a video signal which belong to a moving area in the picture being encoded, said apparatus comprising means for generating a frame-to-frame difference for each of said input samples, means for generating a first value in response to the frame-to-frame differences for input samples in a picture area encompassing a plurality of picture elements, means for generating a second value representing an expected noise level for the input samples in said picture area, and means responsive to a difference between said first value and said second value for generating an energizing signal to indicate that a particular one of said input samples belongs to a moving area.
Claim 2
Dependent Claim
113 words
Apparatus for selecting input samples from a video signal which belong to a moving area in the picture being encoded, said apparatus comprising means for generating a frame-to-frame difference for each of said input samples, means for generating a first value in response to the frame-to-frame differences for input samples in a picture area encompassing a plurality of picture elements, means for generating a second value representing an expected noise level for the input samples in said picture area, and means responsive to a difference between said first value and said second value for generating an energizing signal to indicate that a particular one of said input samples belongs to a moving area.
Claim 3
Dependent Claim
113 words
Apparatus for selecting input samples from a video signal which belong to a moving area in the picture being encoded, said apparatus comprising means for generating a frame-to-frame difference for each of said input samples, means for generating a first value in response to the frame-to-frame differences for input samples in a picture area encompassing a plurality of picture elements, means for generating a second value representing an expected noise level for the input samples in said picture area, and means responsive to a difference between said first value and said second value for generating an energizing signal to indicate that a particular one of said input samples belongs to a moving area.
Claim 4
Dependent Claim
113 words
Apparatus for selecting input samples from a video signal which belong to a moving area in the picture being encoded, said apparatus comprising means for generating a frame-to-frame difference for each of said input samples, means for generating a first value in response to the frame-to-frame differences for input samples in a picture area encompassing a plurality of picture elements, means for generating a second value representing an expected noise level for the input samples in said picture area, and means responsive to a difference between said first value and said second value for generating an energizing signal to indicate that a particular one of said input samples belongs to a moving area.
Claim 5
Dependent Claim
38 words
Apparatus as defined in claim 1 wherein said means for generating a first value includes means for obtaining an absolute value of the weighted algebraic sum of the frame-to-frame difference for said input samples in said picture area.
Claim 6
Dependent Claim
50 words
Apparatus as defined in claim 2 wherein said means for generating a second value includes means for developing an expected noise value in response to each of said input samples, and means for obtaining a weighted summation of the expected noise values corresponding to input samples from said picture area.
Claim 7
Dependent Claim
77 words
Apparatus as defined in claim 1 wherein said means for generating an energizing signal includes threshold means for generating a predetermined logic state for each input sample during which said difference between said first value and said second value exceeds a predetermined threshold level, means for counting said predetermined logic states over a predetermined number of input samples, and means for generating said energizing signal when the number of stored predetermined logic states exceeds a predetermined value.
Claim 8
Dependent Claim
184 words
Apparatus for identifying input samples from a video signal which belong to a moving areA in the picture being encoded, said apparatus comprising means for generating a frame-to-frame difference for each of said input samples, means for developing a summation of the frame-to-frame difference of a selected input sample plus the frame-to-frame difference of a previous input sample having a spatial point location above said input sample in said picture, threshold means responsive to said summation for developing an energizing signal when said summation exceeds a predetermined threshold level, means responsive to said energizing signal from said threshold means for developing a first indication of movement, means for generating a first value in response to the frame-to-frame differences for input samples in a picture area encompassing a plurality of picture elements including the picture element corresponding to said selected input sample, means for generating a second value representing an expected noise level for said input samples in said picture area, and means responsive to a difference between said first value and said second value for developing a second indication of movement in said picture.
Claim 9
Dependent Claim
184 words
Apparatus for identifying input samples from a video signal which belong to a moving areA in the picture being encoded, said apparatus comprising means for generating a frame-to-frame difference for each of said input samples, means for developing a summation of the frame-to-frame difference of a selected input sample plus the frame-to-frame difference of a previous input sample having a spatial point location above said input sample in said picture, threshold means responsive to said summation for developing an energizing signal when said summation exceeds a predetermined threshold level, means responsive to said energizing signal from said threshold means for developing a first indication of movement, means for generating a first value in response to the frame-to-frame differences for input samples in a picture area encompassing a plurality of picture elements including the picture element corresponding to said selected input sample, means for generating a second value representing an expected noise level for said input samples in said picture area, and means responsive to a difference between said first value and said second value for developing a second indication of movement in said picture.
Claim 10
Dependent Claim
62 words
Apparatus as defined in claim 5 wherein said means for developing the first indication of movement includes an isolated point rejection means for inhibiting an indication of movement when an energizing signal output from said threshold means during one input sample is preceded and followed by input samples that do not result in energizing signals at the output of said threshold means.
Claim 11
Dependent Claim
31 words
Apparatus as defined in claim 5 wherein said means for generating a first value includes means for developing a weighted summation of frame-to-frame differences for input samples in said picture area.
Claim 12
Dependent Claim
47 words
Apparatus as defined in claim 7 wherein said means for generating a second value includes means for developing an expected noise value in response to each of said input samples and means for algebraically summing said expected noise value for the input samples in said picture area.
Claim 13
Dependent Claim
85 words
Apparatus as defined in claim 8 wherein said means for developing a second indication of movement includes threshold means for developing a predetermined logic state for each input sample during which the difference between said first value and said second value exceeds a second predetermined threshold level, means for counting the number of predetermined logic states developed over a predetermined number of input samples, and means for developing said second indication of movement when the count of said predetermined logic states exceeds a predetermined number.
Claim 14
Dependent Claim
164 words
Apparatus for determining whether an input sample from a plurality of video signal samples belongs to a moving area in the picture represented by said video signal, said apparatus comprising means for developing a frame-to-frame difference signal for each of said plurality of video signal samples, means for storing frame-to-frame difference signals corresponding to said input sample and to video signal samples from a predetermined picture area around said input sample, means for generating a first value in response to the algebraic sum of the frame-to-frame difference signals in said means for storing, means responsive to said video signal samples for generating a second value representing the expected amplitude of noise in said first value, means for subtracting said second value from said first value to obtain a third value whose amplitude is an indication of movement in said predetermined area, and means responsive to said third value for generating an energizing signal to indicate that said input sample belongs to a moving area.
Claim 15
Dependent Claim
164 words
Apparatus for determining whether an input sample from a plurality of video signal samples belongs to a moving area in the picture represented by said video signal, said apparatus comprising means for developing a frame-to-frame difference signal for each of said plurality of video signal samples, means for storing frame-to-frame difference signals corresponding to said input sample and to video signal samples from a predetermined picture area around said input sample, means for generating a first value in response to the algebraic sum of the frame-to-frame difference signals in said means for storing, means responsive to said video signal samples for generating a second value representing the expected amplitude of noise in said first value, means for subtracting said second value from said first value to obtain a third value whose amplitude is an indication of movement in said predetermined area, and means responsive to said third value for generating an energizing signal to indicate that said input sample belongs to a moving area.
Claim 16
Dependent Claim
92 words
Apparatus as defined in claim 10 wherein the apparatus further includes a summation means for obtaining an algebraic sum of the frame-to-frame difference signal corresponding to said input signal and the frame-to-frame difference signal corresponding to at least one other input signal in said storage means, threshold means for generating an energizing signal in response to an output from said summAtion means which exceeds a predetermined threshold level, and means responsive to the energizing signal from said threshold means for developing an indication that said input sample belongs to a moving area.
Claim 17
Dependent Claim
56 words
Apparatus as defined in claim 11 wherein said means for developing an indication of movement includes means for inhibiting an indication of movement when an energizing signal from said threshold means corresponding to said input sample is preceded and followed by input samples that do not result in an energizing signal out of said threshold means.
Claim 18
Dependent Claim
150 words
Apparatus for identifying the video signal samples that belong to a moving area in the picture represented by said video signal samples, said apparatus comprising means responsive to said video signal samples for developing a frame-to-frame difference signal for each of said video signal samples, means responsive to frame-to-frame difference signal corresponding to a predetermined number of video signal samples for developing a first indication of movement, means for generating a movement signal whose amplitude is a function of the frame-to-frame difference signals corresponding to a predetermined number of video signal samples, threshold means having a variable sensitivity for developing a second indication of movement in response to the amplitude of said movement signal during a predetermined number of input samples, and means responsive to either a first or a second indication of movement and to the amplitude of aid movement signal for changing the sensitivity of said threshold means.
Claim 19
Dependent Claim
150 words
Apparatus for identifying the video signal samples that belong to a moving area in the picture represented by said video signal samples, said apparatus comprising means responsive to said video signal samples for developing a frame-to-frame difference signal for each of said video signal samples, means responsive to frame-to-frame difference signal corresponding to a predetermined number of video signal samples for developing a first indication of movement, means for generating a movement signal whose amplitude is a function of the frame-to-frame difference signals corresponding to a predetermined number of video signal samples, threshold means having a variable sensitivity for developing a second indication of movement in response to the amplitude of said movement signal during a predetermined number of input samples, and means responsive to either a first or a second indication of movement and to the amplitude of aid movement signal for changing the sensitivity of said threshold means.
Claim 20
Dependent Claim
62 words
Apparatus as defined in claim 13 wherein said threshold means for developing a second indication of movement includes a threshold circuit for developing an energizing signal during each video signal sample when said movement signal exceeds a predetermined threshold level, and first memory means for storing the energizing signals produced by said threshold circuit during a predetermined number of video signal samples.
Claim 21
Dependent Claim
106 words
Apparatus as defined in claim 14 wherein said video signal samples occur in periodic field intervals, said means for changing the sensitivity develops an energizing signal in response to a movement signal in excess of a predetermined level being simultaneously present with either a first or a second indication of movement, and said means for developing a second indication of movement further includes means for delaying the energizing signal from said means for changing the sensitivity by a duration equal to one field interval, and a second memory means for storing the delayed energizing signals which occur during a second predetermined number of video signal samples.
Claim 22
Dependent Claim
62 words
Apparatus as defined in claim 15 wherein said threshold means for developing a second indication of movement further includes summation means for determining the total number of energizing signals stored in said first and second memory means, and a second threshold circuit for developing said second indication of movement when the total number of stored energizing signals exceeds a third predetermined number.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |