US5751378A
Expired / Lapsed
US
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Scene change detector for digital video
Assignee: Google Technology Holdings LLC
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Filing: 1996-09-27
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Granted: 1998-05-12
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Expires: 2016-09-27
Abstract
Abstract In a method for detecting a scene change between a prior video picture and a current video picture of a sequence of pictures, an average luminance value is determined for a block pair of the prior and current video pictures. Preferably, the blocks of the block pair are located, respectively, in the same relative position in the prior and current pictures. An incremental visual sensation value is determined using a difference between the average luminance values. If the incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated. In particular, if the minimum of the average luminance values of the current and prior picture blocks exceeds a dark scene threshold, the incremental visual sensation value is determined using the ratio of (a) the absolute value of the difference between the average luminance values, and (b) the minimum of the average luminance values of the current and prior picture blocks. Otherwise, the incremental visual sensation value is determined using the ratio of (a) the absolute value of the difference, and (b) the dark scene threshold. The method may be optimized by adjusting the block size based on the relative amount of motion and the current picture type.
Inventors
- 👤 Xuemin Chen
- 👤 Vincent Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:30
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/147; G; G06; G06T; G06T7/00; G06T7/20; G06T7/254; H04N19/00; H04N19/10; H04N19/134; H04N19/142; H04N19/169; H04N19/179; H04N19/85; H04N19/87; H04N5/144; H04N5/145
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
148 words
A method for detecting a scene change between a prior video picture and a current video picture, comprising the steps of: determining average luminance values of a block pair of said prior and current video pictures; determining an incremental visual sensation value using a difference between said average luminance values; determining a minimum of said average luminance values of said current and prior picture blocks, wherein: if said minimum exceeds a dark scene threshold, said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said minimum; if said minimum does not exceed a dark scene threshold, said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said dark scene threshold; and if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 2
Independent Claim
148 words
A method for detecting a scene change between a prior video picture and a current video picture, comprising the steps of: determining average luminance values of a block pair of said prior and current video pictures; determining an incremental visual sensation value using a difference between said average luminance values; determining a minimum of said average luminance values of said current and prior picture blocks, wherein: if said minimum exceeds a dark scene threshold, said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said minimum; if said minimum does not exceed a dark scene threshold, said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said dark scene threshold; and if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said block contrast threshold level is approximately fifteen to approximately twenty-five times a Weber fraction constant.
Claim 4
Dependent Claim
26 words
The method of claim 1, wherein said blocks of said block pair are located, respectively, in the same relative position in said prior and current pictures.
Claim 5
Dependent Claim
18 words
The method of claim 1, wherein: said dark scene threshold is approximately 10% of a maximum gray level.
Claim 6
Dependent Claim
76 words
The method of claim 1, wherein: said difference between average luminance values is determined for a plurality of block pairs of said prior and current video pictures; and said incremental visual sensation value is determined for each of said block pairs using said differences; wherein: if said incremental visual sensation value exceeds the block contrast threshold level for a threshold proportion of block pairs in said current and prior video pictures, a scene change is indicated.
Claim 7
Dependent Claim
15 words
The method of claim 5, wherein said threshold proportion is approximately 80% to approximately 90%.
Claim 8
Independent Claim
151 words
An apparatus for detecting a scene change between a prior video picture and a current video picture, comprising: means for determining average luminance values of a block pair of said prior and current video pictures; means for determining an incremental visual sensation value using a difference between said average luminance values; means for determining a minimum of said average luminance values of said current and prior picture blocks, wherein: if said minimum exceeds a dark scene threshold, said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said minimum; if said minimum does not exceed a dark scene threshold said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said dark scene threshold; and if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 9
Independent Claim
151 words
An apparatus for detecting a scene change between a prior video picture and a current video picture, comprising: means for determining average luminance values of a block pair of said prior and current video pictures; means for determining an incremental visual sensation value using a difference between said average luminance values; means for determining a minimum of said average luminance values of said current and prior picture blocks, wherein: if said minimum exceeds a dark scene threshold, said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said minimum; if said minimum does not exceed a dark scene threshold said incremental visual sensation value is determined using the ratio of (a) the absolute value of said difference, and (b) said dark scene threshold; and if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 10
Dependent Claim
22 words
The apparatus of claim 7, wherein said block contrast threshold level is approximately fifteen to approximately twenty-five times a Weber fraction constant.
Claim 11
Dependent Claim
79 words
The apparatus of claim 7, further comprising: means for determining said difference between average luminance values for a plurality of block pairs of said prior and current video pictures; and means for determining said incremental visual sensation value for each of said block pairs using said differences; wherein: if said incremental visual sensation value exceeds the block contrast threshold level for a threshold proportion of block pairs in said current and prior video pictures, a scene change is indicated.
Claim 12
Dependent Claim
15 words
The apparatus of claim 9, wherein said threshold proportion is approximately 80% to approximately 90%.
Claim 13
Dependent Claim
18 words
The apparatus of claim 7, wherein: said dark scene threshold is approximately 10% of a maximum gray level.
Claim 14
Independent Claim
95 words
A method for detecting a scene change between a prior video picture and a current video picture, comprising the steps of: determining average luminance values of a block pair of said prior and current video pictures; determining an incremental visual sensation value using a difference between said average luminance values; determining a relative amount of motion between said blocks of said block pair; and adjusting a size of said blocks based on said relative amount of motion; wherein: if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 15
Independent Claim
95 words
A method for detecting a scene change between a prior video picture and a current video picture, comprising the steps of: determining average luminance values of a block pair of said prior and current video pictures; determining an incremental visual sensation value using a difference between said average luminance values; determining a relative amount of motion between said blocks of said block pair; and adjusting a size of said blocks based on said relative amount of motion; wherein: if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 16
Dependent Claim
20 words
The method of claim 12, wherein the size of said blocks is increased as said relative amount of motion increases.
Claim 17
Dependent Claim
84 words
The method of claim 12, wherein said step of determining a relative amount of motion comprises the further steps of: determining a sum of the absolute value of a horizontal motion vector and the absolute value of a vertical motion vector; wherein said horizontal and vertical motion vectors are indicative of horizontal and vertical motion, respectively, of a video image of said current picture block relative to a video image of said prior picture block; and determining if said sum exceeds a motion threshold.
Claim 18
Dependent Claim
20 words
The method of claim 14, wherein: said motion threshold is adjusted according to a picture type of said current picture.
Claim 19
Independent Claim
100 words
An apparatus for detecting a scene change between a prior video picture and a current video picture, comprising: means for determining average luminance values of a block pair of said prior and current video pictures; means for determining an incremental visual sensation value using a difference between said average luminance values; means for determining a relative amount of motion between said blocks of said block pair; and means for adjusting a size of said blocks based on said relative amount of motion; wherein: if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 20
Independent Claim
100 words
An apparatus for detecting a scene change between a prior video picture and a current video picture, comprising: means for determining average luminance values of a block pair of said prior and current video pictures; means for determining an incremental visual sensation value using a difference between said average luminance values; means for determining a relative amount of motion between said blocks of said block pair; and means for adjusting a size of said blocks based on said relative amount of motion; wherein: if said incremental visual sensation value exceeds a block contrast threshold level, a scene change is indicated.
Claim 21
Dependent Claim
22 words
The apparatus of claim 16, further comprising: means for increasing the size of said blocks as said relative amount of motion increases.
Claim 22
Dependent Claim
84 words
The apparatus of claim 16, wherein said means for determining a relative amount of motion further comprises: means for determining a sum of the absolute value of a horizontal motion vector and the absolute value of a vertical motion vector; wherein said horizontal and vertical motion vectors are indicative of horizontal and vertical motion, respectively, of a video image of said current picture-block relative to a video image of said prior picture block; and means for determining if said sum exceeds a motion threshold.
Claim 23
Dependent Claim
22 words
The apparatus of claim 18, further comprising: means for adjusting said motion threshold according to a picture type of said current picture.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-11 | 2001-11-10 | 2002-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-11 | 2005-11-10 | 2006-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-11 | 2009-11-10 | 2010-05-12 | $7700.00 | Window Closed / Lapsed |