EP0741496A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
System and method for focused-based image segmentation for video signals
Assignee: AT&T Inc
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Filing: 1996-04-17
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Granted: —
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Expires: 2016-04-17
Abstract
Abstract Motion video is represented by digital signals. The digital signals can be compressed by coding to reduce bitrate and thus save time and expense in transmitting and reproducing the video. The present invention is a system and method for reducing the amount of information required to satisfactorily reproduce video signals by distinguishing more pertinent portions of the video from less pertinent portions. In particular, edges are detected based on amplitude variations in the luminance characteristic of the picture elements. Sharp edges are deemed to be "focused". The portion of the video frame between the focused edges is deemed to be focused, as well. A template is created corresponding to the focused portion. A signal corresponding to the outline of the template is combined with the original frame signal to create a segmented frame signal. When motion detection information is available, a motion-based template may be created and intersected with the focus template. A signal corresponding to the outline of the intersected template may be transmitted with the frame signal as the segmented frame signal.
Inventors
- 👤 Tsuhan Chen
- 👤 Cassandra Turner Swain
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:41
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/10; H04N19/134; H04N19/167; G; G06; G06T; G06T7/00; G06T7/10; G06T7/12; H04N19/102; H04N19/115; H04N19/169; H04N19/17; H04N19/50; H04N19/597; G06T2207/00; G06T2207/20; G06T2207/20021; H04N19/20
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
115 words
A method of segmenting an original frame having blocks into a pertinent portion and a less pertinent portion comprising: acquiring a signal corresponding to the original frame which signal comprises an image attribute for each block; comparing the image attribute of each block to the image attribute of another block; assigning each block a focus measurement based at least in part on the attribute comparison; comparing the focus measurement of each block to a threshold focus measurement; designating the blocks having a focus measurement above the threshold as focused and designating the blocks having a threshold measurement below the threshold as defocused; and creating a segmented frame based, at least in part, on the designations.
Claim 2
Dependent Claim
13 words
The method of claim 1 wherein the image attribute is a luminance component.
Claim 3
Dependent Claim
12 words
The method of claim 2 wherein each block comprises a single pel.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the image attribute is compared with the image attribute of an adjacent block.
Claim 5
Dependent Claim
15 words
The method of claim 1 further comprising the step of smoothing the original frame signal.
Claim 6
Dependent Claim
26 words
The method of claim 5 wherein smoothing the frame signal comprises averaging the luminance component of a block with the luminance component of an adjacent block.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein comparing the image attribute comprises convolving a matrix of pels of a block with an impulse response array.
Claim 8
Dependent Claim
15 words
The method of claim 7 wherein the image response array is a Sobel response array.
Claim 9
Dependent Claim
13 words
The method of claim 8 wherein focus measurement is based on edge width.
Claim 10
Dependent Claim
16 words
The method of claim 9 wherein the focus measurement is inversely proportional to the edge width.
Claim 11
Dependent Claim
13 words
The method of claim 1 further comprising the step of calculating the threshold.
Claim 12
Dependent Claim
17 words
The method of claim 11 wherein threshold calculation is based on a selected percentage of the frame.
Claim 13
Dependent Claim
17 words
The method of claim 12 wherein the selected percentage is based on a bandwidth available for transmission.
Claim 14
Dependent Claim
32 words
The method of claim 1 further comprising creating an outline of the focused portions based on the designations wherein the segmented frame is created based at least in part on the outline.
Claim 15
Dependent Claim
80 words
The method of claim 1 further comprising: measuring the motion of each block; assigning each block a motion value based on the motion measurement; comparing the motion measurement of each block to a threshold motion measurement; and designating the blocks having a motion measurement above the motion threshold as moving and designating the blocks having a motion measurement below the motion threshold as not moving; wherein the segmented frame is created based, at least in part, on the motion designation.
Claim 16
Dependent Claim
50 words
The method of claim 15 further comprising: creating a focus template based on the focus designations; creating a motion template based on the motion designations; and creating a combined template based on the focus template and the motion template; wherein the segmented frame is created based on the combined template.
Claim 17
Dependent Claim
20 words
The method of claim 16 wherein the combined template is the intersection of the motion template and the focus template.
Claim 18
Dependent Claim
27 words
The method of claim 17 further comprising outlining the combined template and generating an outline signal, wherein the segmented frames are created based on the outline signal.
Claim 19
Dependent Claim
72 words
The method of claim 1 wherein the threshold focus measurement is a first threshold focus measurement further comprising: comparing the focus measurement of each block to a second threshold focus measurement; and designating the blocks having a focus measurement between the first threshold focus measurement and the second threshold focus measurement as intermediate; wherein the segmented frame is created based, at least in part, on the designations as focused, intermediate or defocused.
Claim 20
Independent Claim
156 words
An apparatus for generating an output signal representing an outline of pertinent information in a video frame for use in compressing digital signals, said apparatus comprising: receiving means for receiving a digital signal, said received digital signal representing a plurality of blocks, each block having an image attribute; storage means for storing the image attribute of the blocks; and processing means for processing said received digital signal to generate said output signal, said processing means operable to: store at least a matrix of attributes; calculate a focus gradient based, at least in part, on the stored matrix; associate with each block a focus value based on the focus gradient; compare each focus value with a focus threshold; designate each block having a focus value above the focus threshold as focused; designate each block having a focus value below the focus threshold as defocused; define a focus outline based, at least in part, on the focused pels.
Claim 21
Dependent Claim
99 words
The apparatus of claim 20 wherein the processing means is further operable to: calculate a motion gradient based, at least in part, on the stored matrix; associate with each block a motion value based on the motion gradient; compare each motion value with a motion threshold; designate each block having a motion value above the motion threshold as moving; designate each block having a motion value below the threshold as not moving; define a motion outline based, at least in part, on the moving blocks; and define a motion/focus outline based on the focus template and the motion template.
Claim 22
Dependent Claim
12 words
The apparatus of claim 20 wherein the attribute is a luminance component.
Claim 23
Dependent Claim
17 words
The apparatus of claim 20 wherein the processing means is further operable to calculate the focus threshold.
Claim 24
Dependent Claim
26 words
The apparatus of claim 20 wherein the processing means is further operable to calculate the focus threshold based on a selected portion of the video frame.
Claim 25
Dependent Claim
22 words
The apparatus of claim 20 wherein the processing means is further operable to calculate the focus threshold based on a predetermined bandwidth.
Claim 26
Dependent Claim
110 words
A prefilter for segmenting a motion video frame into more pertinent portions and less pertinent portions comprising: means for receiving a signal corresponding to an original frame, the original frame signal having portions, wherein each portion has a depth; means for measuring the depth of each portion of the original frame signal; means for designating each portion as foreground or background based, at least in part, on the depth measurement; means for generating a template based, at least in part, on the designations; means for generating a template signal corresponding to the template; and means for combining the original frame signal and the template signal into a segmented frame signal.
Claim 27
Dependent Claim
23 words
The prefilter of claim 26 wherein the means for measuring depth includes a means for detecting an edge in the original frame signal.
Claim 28
Dependent Claim
28 words
The prefilter of claim 27 wherein the means for detecting an edge comprises a means for comparing an image attribute for adjacent portions of the original frame signal.
Claim 29
Dependent Claim
10 words
The prefilter of claim 28 wherein the portions are pels.
Claim 30
Dependent Claim
112 words
The prefilter of claim 26 wherein the template is a focus template and further comprising: means for measuring the motion of each portion of the original frame signal; means for designating each portion either as moving or nonmoving based, at least in part, on the motion measurement; means for generating a motion template based, at least in part, on the motion designations; means for generating a motion template signal corresponding to the motion template; means for comparing the motion template signal and the focus template signal to derive a combined motion/focus template signal; and means for combining the original frame signal and the motion/focus template signal into a combined segmented frame signal.
Claim 31
Dependent Claim
54 words
The prefilter of claim 36 wherein the means for generating a template comprises: means for designating each portion of the frame signal disposed between foreground portions located at one horizontal level as foreground; and means for designating each portion of the frame signal disposed between foreground portions located at one vertical level as foreground.
Claim 32
Dependent Claim
26 words
The prefilter of claim 26 wherein the means for generating a template signal comprises means for generating a signal corresponding to an outline of the template.
Claim 33
Independent Claim
99 words
A method of generating a signal corresponding to a segmented frame comprising: acquiring a signal corresponding to an original frame which original frame signal comprises an image attribute for each pel; comparing the image attribute of each pel to the image attribute of another pel; detecting edges in the original frame signal based on the attribute comparison; designating the pels located at edges as focused; designating the pels not located at edges as defocused; generating a signal corresponding to the focused pels; and creating a segmented frame signal based on the focused pel signal and the original frame signal.
Claim 34
Dependent Claim
82 words
The method of claim 33 further comprising: comparing each pel to a corresponding pel in a different frame; measuring the movement of each pel based on the comparison; comparing the movement measurement with a movement threshold, designating pels with a movement measurement above the threshold as moving, and designating the pels with a movement measurement below the threshold as nonmoving; and generating a signal corresponding to the moving pels; wherein the segmented frame signal is further based on the moving pel signal.
References Cited (Backward Citations)
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