Patent US7190829B2 successfully refreshed from Google Patents.
US7190829B2
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Speedup of face detection in digital images
Assignee: Microsoft Technology Licensing LLC
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Filing: 2003-06-30
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Granted: 2007-03-13
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Expires: 2023-06-30
Abstract
Abstract Improved methods and apparatuses are provided for use in face detection. The methods and apparatuses significantly reduce the number of candidate windows within a digital image that need to be processed using more complex and/or time consuming face detection algorithms. The improved methods and apparatuses include a skin color filter and an adaptive non-face skipping scheme.
Inventors
- 👤 Lei Zhang
- 👤 Mingjing Li
- 👤 Hong-Jiang Zhang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:31
CPC Classifications
G; G06; G06V; G06V40/00; G06V40/10; G06V40/16; G06V40/161; G06V40/162; G06F; G06F18/00; G06F18/20; G06F18/21; G06F18/214
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
152 words
A method for use in face detection, the method comprising: establishing a plurality of initial candidate windows within a digital image, said digital image having a plurality of pixels represented by color space information; for each initial candidate window, examining said color space information for each of at least a portion of said pixels within said initial candidate window and classifying each of said examined pixels as being either a skin color pixel or a non-skin color pixel; and establishing a plurality of subsequent candidate windows that includes at least a portion of said initial candidate windows based on said classified pixels within each of said initial candidate windows; wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes classifying “gray” pixels as skin color pixels; and wherein said “gray” pixels have associated chrominance information Cr and Cb substantially equal to zero.
Claim 2
Independent Claim
152 words
A method for use in face detection, the method comprising: establishing a plurality of initial candidate windows within a digital image, said digital image having a plurality of pixels represented by color space information; for each initial candidate window, examining said color space information for each of at least a portion of said pixels within said initial candidate window and classifying each of said examined pixels as being either a skin color pixel or a non-skin color pixel; and establishing a plurality of subsequent candidate windows that includes at least a portion of said initial candidate windows based on said classified pixels within each of said initial candidate windows; wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes classifying “gray” pixels as skin color pixels; and wherein said “gray” pixels have associated chrominance information Cr and Cb substantially equal to zero.
Claim 3
Dependent Claim
18 words
The method as recited in claim 1 , wherein said color space information includes at least chrominance information.
Claim 4
Dependent Claim
16 words
The method as recited in claim 2 , wherein said color space information includes luminance information.
Claim 5
Dependent Claim
19 words
The method as recited in claim 3 , wherein said color space information includes Y, Cr and Cb information.
Claim 6
Dependent Claim
23 words
The method as recited in claim 1 , wherein said color space information includes red (R), green (G) and blue (B) color information.
Claim 7
Dependent Claim
83 words
The method as recited in claim 1 , wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes applying logic based on skin = { true , if ( Cr - 1.2 * Cb + 12 ≥ 0 ) and ( Cr + 0.675 * Cb + 2.5 ≥ 0 ) false otherwise , wherein Cr and Gb represent chrominance information associated with said pixel being classified.
Claim 8
Dependent Claim
87 words
The method as recited in claim 1 , wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes applying logic based on non - skin = { false , if ( Cr - 1.2 * Cb + 12 ≥ 0 ) and ( Cr + 0.675 * Cb + 2.5 ≥ 0 ) true otherwise , wherein Cr and Cb represent chrominance information associated with said pixel being classified.
Claim 9
Dependent Claim
81 words
The method as recited in claim 1 , wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes converting RGB color space information to at least corresponding chrominance information Cr and Cb as follows: Cr=0.5000* r −0.4187* g −0.0813* b and Cb =−0.1687* r −0.3313* g =0.5000* b , wherein r is red color information, g is green color information, and b is blue color information for said pixel being examined.
Claim 10
Dependent Claim
37 words
The method as recited in claim 8 , wherein convening said RGB color space information further includes converting said RGB color space information to corresponding luminance information Y as follows: Y= 0.2990* r 0.5870* g =0.1140* b.
Claim 11
Dependent Claim
57 words
The method as recited in claim 1 , wherein establishing said is plurality of subsequent candidate windows further includes, for each of said initial candidate windows, comparing a total number of said skin color classified pixels with a threshold value and based on said comparison identifying said initial candidate window as one of said subsequent candidate windows.
Claim 12
Dependent Claim
49 words
The method as recited in claim 10 , wherein said threshold value is determined as T=α*W*H, wherein T is said threshold value, W is a width of said initial candidate window, H is a height of said initial candidate window, and α is a weight parameter greater than zero.
Claim 13
Dependent Claim
14 words
The method as recited in claim 11 , wherein α between 0.3 and 0.7.
Claim 14
Dependent Claim
12 words
The method as recited in claim 12 , wherein α is 0.5.
Claim 15
Dependent Claim
56 words
The method as recited in claim 1 , wherein establishing said plurality of subsequent candidate windows further includes, for each of said initial candidate windows, comparing a total number of said non-skin color classified pixels with a threshold value and based on said comparison identifying said initial candidate window as one of said subsequent candidate windows.
Claim 16
Dependent Claim
49 words
The method as recited in claim 14 , wherein said threshold value is determined as T=α*W*H, wherein T is said threshold value, W is a width of said initial candidate window, H is a height of said initial candidate window, and α is a weight parameter greater than zero.
Claim 17
Dependent Claim
14 words
The method as recited in claim 15 , wherein α between 0.3 and 0.7.
Claim 18
Dependent Claim
12 words
The method as recited in claim 16 , wherein a is 0.5.
Claim 19
Dependent Claim
30 words
The method as recited in claim 1 , wherein at least one of said initial candidate windows includes an intermediate representation of at least a portion of said digital image.
Claim 20
Dependent Claim
16 words
The method as recited in claim 18 , wherein said intermediate representation includes an integral image.
Claim 21
Dependent Claim
19 words
The method as recited in claim 1 , further comprising: processing said subsequent candidate windows using a face detector.
Claim 22
Dependent Claim
46 words
The method as recited in claim 20 , wherein processing said subsequent candidate windows using a face detector further includes: applying an adaptive non-face skipping scheme to establish a plurality of further processed candidate windows that includes a subset of said plurality of subsequent candidate windows.
Claim 23
Dependent Claim
158 words
A computer-readable medium having computer-implementable instructions for causing one or more processing units to perform acts comprising: establishing a plurality of initial candidate windows within a digital image, said digital image having a plurality of pixels represented by color space information; for each initial candidate window, examining said color space information for each of at least a portion of said pixels within said initial candidate window; classifying each of said examined pixels as being either a skin color pixel or a non-skin color pixel; and establishing a plurality of subsequent candidate windows that includes at least a portion of said initial candidate windows based on said classified pixels within each of said initial candidate windows; wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes classifying “gray” pixels as skin color pixels; and wherein said “gray” pixels have associated chrominance information Cr and Cb substantially equal to zero.
Claim 24
Dependent Claim
158 words
A computer-readable medium having computer-implementable instructions for causing one or more processing units to perform acts comprising: establishing a plurality of initial candidate windows within a digital image, said digital image having a plurality of pixels represented by color space information; for each initial candidate window, examining said color space information for each of at least a portion of said pixels within said initial candidate window; classifying each of said examined pixels as being either a skin color pixel or a non-skin color pixel; and establishing a plurality of subsequent candidate windows that includes at least a portion of said initial candidate windows based on said classified pixels within each of said initial candidate windows; wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes classifying “gray” pixels as skin color pixels; and wherein said “gray” pixels have associated chrominance information Cr and Cb substantially equal to zero.
Claim 25
Dependent Claim
19 words
The computer-readable medium as recited in claim 22 , wherein said color space information includes at least chrominance information.
Claim 26
Dependent Claim
17 words
The computer-readable medium as recited in claim 23 , wherein said color space information includes luminance information.
Claim 27
Dependent Claim
20 words
The computer-readable medium as recited in claim 24 , wherein said color space information includes Y, Cr and Cb information.
Claim 28
Dependent Claim
24 words
The computer-readable medium as recited in claim 22 , wherein said color space information includes red (R), green (G) and blue (B) color information.
Claim 29
Dependent Claim
83 words
The computer-readable medium as recited in claim 22 , wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes applying logic based on skin = { true , if ( Cr - 1.2 * Cb + 12 ≥ 0 ) and ( Cr + 0.675 * Cb + 2.5 ≥ 0 ) false otherwise , wherein Cr and Cb represent chrominance information associated with said pixel being classified.
Claim 30
Dependent Claim
88 words
The computer-readable medium as recited in claim 22 , wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes applying logic based on non - skin = { false , if ( Cr - 1.2 * Cb + 12 ≥ 0 ) and ( Cr + 0.675 * Cb + 2.5 ≥ 0 ) true otherwise , wherein Cr and Cb represent chrominance information associated with said pixel being classified.
Claim 31
Dependent Claim
81 words
The computer-readable medium as recited in claim 22 , wherein classifying each of said examined pixels as either said skin color pixel or said non-skin color pixel further includes converting RGB color space information to at least corresponding chrominance information Cr and Cb as follows: Cr=0.5000* r −0.4187* g −0.0813* b and Cb= −0.1687* r 0.3313* g =0.5000* b, wherein r is red color information, g is green color information, and b is blue color information for said pixel being examined.
Claim 32
Dependent Claim
38 words
The computer-readable medium as recited in claim 29 , wherein converting said RUB color space information further includes converting said RUB color space information to corresponding luminance information Y as follows: Y= 0.2990* r =0.5870* g =0.1140* b.
Claim 33
Dependent Claim
57 words
The computer-readable medium as recited in claim 22 , wherein establishing said plurality of subsequent candidate windows further includes, for each of said initial candidate windows, comparing a total number of said skin color classified pixels with a threshold value and based on said comparison identifying said initial candidate window as one of said subsequent candidate windows.
Claim 34
Dependent Claim
51 words
The computer-readable medium as recited in claim 31 , wherein said threshold value is determined as T=α*W*H wherein T is said threshold value, W is a width of said initial candidate window, H is a height of said is initial candidate window, and α is a weight parameter greater than zero.
Claim 35
Dependent Claim
15 words
The computer-readable medium as recited in claim 32 , wherein a between 0.3 and 0.7.
Claim 36
Dependent Claim
13 words
The computer-readable medium as recited in claim 33 , wherein α is 0.5.
Claim 37
Dependent Claim
57 words
The computer-readable medium as recited in claim 22 , wherein establishing said plurality of subsequent candidate windows further includes, for each of said initial candidate windows, comparing a total number of said non-skin color classified pixels with a threshold value and based on said comparison identifying said initial candidate window as one of said subsequent candidate windows.
Claim 38
Dependent Claim
50 words
The computer-readable medium as recited in claim 35 , wherein said threshold value is determined as T=α*W*H, wherein T is said threshold value, W is a width of said initial candidate window, H is a height of said initial candidate window, and α is a weight parameter greater than zero.
Claim 39
Dependent Claim
15 words
The computer-readable medium as recited in claim 36 , wherein α between 0.3 and 0.7.
Claim 40
Dependent Claim
12 words
The computer-readable medium as recited in claim 37 , wherein α 0.5.
Claim 41
Dependent Claim
31 words
The computer-readable medium as recited in claim 22 , wherein at least one of said initial candidate windows includes an intermediate representation of at least a portion of said digital image.
Claim 42
Dependent Claim
17 words
The computer-readable medium as recited in claim 39 , wherein said intermediate representation includes an integral image.
Claim 43
Dependent Claim
20 words
The computer-readable medium as recited in claim 22 , further comprising processing said subsequent candidate windows using a face detector.
Claim 44
Dependent Claim
47 words
The computer-readable medium as recited in claim 41 , wherein processing said subsequent candidate windows using a face detector further includes: applying an adaptive non-face skipping scheme to establish a plurality of further processed candidate windows that includes a subset of said plurality of subsequent candidate windows.
Claim 45
Independent Claim
171 words
An apparatus for use in face detection, the apparatus comprising: memory suitable for storing a digital image having a plurality of image pixels represented by color space information; and logic operatively coupled to said memory and configured to: establish a plurality of initial candidate windows using said digital image, wherein each initial candidate window including pixels associated with at least a portion of said image pixels, for each initial candidate window, examine said color space information for each of at feast a portion of said pixels within said initial candidate window and classifying each of said examined pixels as being either a skin color pixel or a non-skin color pixel, and establish a plurality of subsequent candidate windows that includes at least a portion of said initial candidate windows based on said classified pixels within each of said initial candidate windows; wherein said logic is further configured to classify “gray” pixels as skin color pixels; and wherein said “gray” pixels have associated chrominance information Cr and Cb substantially equal to zero.
Claim 46
Independent Claim
171 words
An apparatus for use in face detection, the apparatus comprising: memory suitable for storing a digital image having a plurality of image pixels represented by color space information; and logic operatively coupled to said memory and configured to: establish a plurality of initial candidate windows using said digital image, wherein each initial candidate window including pixels associated with at least a portion of said image pixels, for each initial candidate window, examine said color space information for each of at feast a portion of said pixels within said initial candidate window and classifying each of said examined pixels as being either a skin color pixel or a non-skin color pixel, and establish a plurality of subsequent candidate windows that includes at least a portion of said initial candidate windows based on said classified pixels within each of said initial candidate windows; wherein said logic is further configured to classify “gray” pixels as skin color pixels; and wherein said “gray” pixels have associated chrominance information Cr and Cb substantially equal to zero.
Claim 47
Dependent Claim
21 words
The apparatus as recited in claim 43 , wherein said color space information includes at least chrominance information and luminance information.
Claim 48
Dependent Claim
23 words
The apparatus as recited in claim 43 , wherein said color space information includes red (R), green (G) and blue (B) color information.
Claim 49
Dependent Claim
83 words
The apparatus as recited in claim 43 , wherein logic is configured to classify each of said examined pixels as either said skin color pixel or said non-skin color pixel based on skin = { true , if ( Cr - 1.2 * Cb + 12 ≥ 0 ) and ( Cr + 0.675 * Cb + 2.5 ≥ 0 ) false otherwise , wherein Cr and Cb represent chrominance information associated with said pixel being classified.
Claim 50
Dependent Claim
87 words
The apparatus as recited in claim 43 , wherein logic is configured to classify each of said examined pixels as either said skin color pixel or said non-skin color pixel based on non - skin = { false , if ( Cr - 1.2 * Cb + 12 ≥ 0 ) and ( Cr + 0.675 * Cb + 2.5 ≥ 0 ) true otherwise , wherein Cr and Cb represent chrominance information associated with said pixel being classified.
Claim 51
Dependent Claim
67 words
The apparatus as recited in claim 43 , wherein said logic is further configured to convert RGB color space information to at least corresponding chrominance information Cr and Cb as follows: Cr=0.5000* r −0.4187* g −0.0813* b and Cb= −0.1687* r −0.3313* g =0.5000* b, wherein r is red color information, g is green color information, and b is blue color information for said pixel being examined.
Claim 52
Dependent Claim
53 words
The apparatus as recited in claim 43 , wherein said logic is further configured to: for each of said initial candidate windows, compare a total number of said skin color classified pixels with a threshold value, and based on said comparison, identify said initial candidate window as one of said subsequent candidate windows.
Claim 53
Dependent Claim
62 words
The apparatus as recited in claim 49 , wherein said threshold value is determined by said logic as T=α*W*H, wherein T is said threshold value, W is a width of said initial candidate window, H is a height of said initial candidate window, and α is a weight parameter greater than zero, and wherein α is between about 0.3 and about 0.7.
Claim 54
Dependent Claim
53 words
The apparatus as recited in claim 43 , wherein said logic is further configured to: for each of said initial candidate windows, comparing a total number of said non-skin color classified pixels with a threshold value, and based on said comparison identify said initial candidate window as one of said subsequent candidate windows.
Claim 55
Dependent Claim
62 words
The apparatus as recited in claim 51 , wherein said threshold value is determined by said logic as T=α*W*H, wherein T is said threshold value, W is a width of said initial candidate window, H is a height of said initial candidate window, and α is a weight parameter greater than zero, and wherein α is between about 0.3 and about 0.7.
Claim 56
Dependent Claim
30 words
The apparatus as recited in claim 43 , wherein at least one of said initial candidate windows includes an intermediate representation of at least a portion of said digital image.
Claim 57
Dependent Claim
16 words
The apparatus as recited in claim 53 , wherein said intermediate representation includes an integral image.
Claim 58
Dependent Claim
26 words
The apparatus as recited in claim 43 , further comprising: face detector logic operatively coupled to said memory and configured to process said subsequent candidate windows.
Claim 59
Dependent Claim
42 words
The apparatus as recited in claim 55 , wherein said face detector logic is configured to: apply an adaptive non-face skipping scheme to establish a plurality of further processed candidate windows that includes a subset of said plurality of subsequent candidate windows.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2010-03-12 | 2010-09-11 | 2011-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2014-03-12 | 2014-09-11 | 2015-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2018-03-12 | 2018-09-11 | 2019-03-13 | $7700.00 | Window Closed / Lapsed |