Face Recognition 人脸识别PPT课件
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What are they doing?
• Activities
All of these are classification problems
• Choose one class from a list of possible candidates
CSE 576, Spring 2008
Face Recognition and Detection
Face Recognition and Detection
1
Recognition problems
What is it?
• Object and scene recognition
Who is it?
• Identity recognition
Where is it?
• Object detection
CSE 576, Spring 2008
Face Recognition and Detection
7
Skin detection
skin
Skin pixels have a distinctive range of colors
• Corresponds to region(s) in RGB color space
– skin pixels shown in orange, non-skin pixels shown in gray – some skin pixels may be outside the region, non-skin pixels inside.
CSE 576, Spring 2008
and parts [Moghaddan & ing [Viola & Jones]
CSE 576, Spring 2008
Face Recognition and Detection
6
Face detection
How to tell if a face is present?
Face Recognition and Detection
The “Margaret Thatcher Illusion”, by Peter Thompson
Computer Vision
CSE576, Spring 2008
Richard Szeliski
CSE 576, Spring 2008
CSE 576, Spring 2008
Face Recognition and Detection
4
Sources
• Steve Seitz, CSE 455/576, previous quarters • Fei-Fei, Fergus, Torralba, CVPR’2007 course • Efros, CMU 16-721 Learning in Vision • Freeman, MIT 6.869 Computer Vision: Learning • Linda Shapiro, CSE 576, Spring 2007
2
What is recognition?
A different taxonomy from [Csurka et al. 2006]: • Recognition
• Where is this particular object?
• Categorization
• What kind of object(s) is(are) present?
• Turk, M. and Pentland, A. Eigenfaces for recognition. Journal of Cognitive Neuroscience, 1991
• Viola, P. A. and Jones, M. J. (2004). Robust real-time face detection. IJCV, 57(2), 137–154.
3
Readings
• C. Bishop, “Neural Networks for Pattern Recognition”, Oxford University Press, 1998, Chapter 1.
• Forsyth and Ponce, Chap 22.3 (through 22.3.2-eigenfaces)
• Content-based image retrieval
• Find me something that looks similar
• Detection
• Locate all instances of a given class
CSE 576, Spring 2008
Face Recognition and Detection
Face Recognition and Detection
9
Skin classifier
Given X = (R,G,B): how to determine if it is skin or not?
CSE 576, Spring 2008
Face Recognition and Detection
5
Today’s lecture
Face recognition and detection • color-based skin detection • recognition: eigenfaces [Turk & Pentland]
8
Skin detection
Learn the skin region from examples
• Manually label skin/non pixels in one or more “training images” • Plot the training data in RGB space
Skin classifier
• A pixel X = (R,G,B) is skin if it is in the skin (color) region • How to find this region?
CSE 576, Spring 2008
Face Recognition and Detection
• Activities
All of these are classification problems
• Choose one class from a list of possible candidates
CSE 576, Spring 2008
Face Recognition and Detection
Face Recognition and Detection
1
Recognition problems
What is it?
• Object and scene recognition
Who is it?
• Identity recognition
Where is it?
• Object detection
CSE 576, Spring 2008
Face Recognition and Detection
7
Skin detection
skin
Skin pixels have a distinctive range of colors
• Corresponds to region(s) in RGB color space
– skin pixels shown in orange, non-skin pixels shown in gray – some skin pixels may be outside the region, non-skin pixels inside.
CSE 576, Spring 2008
and parts [Moghaddan & ing [Viola & Jones]
CSE 576, Spring 2008
Face Recognition and Detection
6
Face detection
How to tell if a face is present?
Face Recognition and Detection
The “Margaret Thatcher Illusion”, by Peter Thompson
Computer Vision
CSE576, Spring 2008
Richard Szeliski
CSE 576, Spring 2008
CSE 576, Spring 2008
Face Recognition and Detection
4
Sources
• Steve Seitz, CSE 455/576, previous quarters • Fei-Fei, Fergus, Torralba, CVPR’2007 course • Efros, CMU 16-721 Learning in Vision • Freeman, MIT 6.869 Computer Vision: Learning • Linda Shapiro, CSE 576, Spring 2007
2
What is recognition?
A different taxonomy from [Csurka et al. 2006]: • Recognition
• Where is this particular object?
• Categorization
• What kind of object(s) is(are) present?
• Turk, M. and Pentland, A. Eigenfaces for recognition. Journal of Cognitive Neuroscience, 1991
• Viola, P. A. and Jones, M. J. (2004). Robust real-time face detection. IJCV, 57(2), 137–154.
3
Readings
• C. Bishop, “Neural Networks for Pattern Recognition”, Oxford University Press, 1998, Chapter 1.
• Forsyth and Ponce, Chap 22.3 (through 22.3.2-eigenfaces)
• Content-based image retrieval
• Find me something that looks similar
• Detection
• Locate all instances of a given class
CSE 576, Spring 2008
Face Recognition and Detection
Face Recognition and Detection
9
Skin classifier
Given X = (R,G,B): how to determine if it is skin or not?
CSE 576, Spring 2008
Face Recognition and Detection
5
Today’s lecture
Face recognition and detection • color-based skin detection • recognition: eigenfaces [Turk & Pentland]
8
Skin detection
Learn the skin region from examples
• Manually label skin/non pixels in one or more “training images” • Plot the training data in RGB space
Skin classifier
• A pixel X = (R,G,B) is skin if it is in the skin (color) region • How to find this region?
CSE 576, Spring 2008
Face Recognition and Detection