Lecture 3.2.0 Introduction to keypoint features€¦ · Use of features in this course • This...
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Lecture 3.2.0 Introduction to keypoint features Trym Vegard Haavardsholm
Transcript of Lecture 3.2.0 Introduction to keypoint features€¦ · Use of features in this course • This...
Lecture 3.2.0Introduction to keypoint features
Trym Vegard Haavardsholm
Why extract features?
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• Example: Panorama stitching– How do we combine two images?
Why extract features?
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• Example: Panorama stitching– How do we combine two images?
Step 1: Extract features
Why extract features?
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• Example: Panorama stitching– How do we combine two images?
Step 1: Extract featuresStep 2: Match features
Why extract features?
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• Example: Panorama stitching– How do we combine two images?
Step 1: Extract featuresStep 2: Match featuresStep 3: Align images
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Correspondences across views
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Correspondences across views
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Correspondences across views
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Correspondences across views
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Characteristics of good features
• Repeatability
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Characteristics of good features
• Repeatability• Distinctiveness
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Characteristics of good features
• Repeatability• Distinctiveness
• Efficiency
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Characteristics of good features
• Repeatability• Distinctiveness
• Efficiency• Locality
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Applications: Automatic Panoramas
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Credit: Matt Brown
Application: Object Recognition
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Application: 3D reconstruction and navigation
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Use of features in this course
• This week:– Lecture 3.2.1: Corner features– Lecture 3.2.2: Blob features
• Next week:– Feature descriptors– Feature matching– Homography estimation from correspondences
• Weeks after that:– Part II: World geometry and 3D– Part III: Scene analysis
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