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Published byBetty Williamson Modified over 9 years ago
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Computer Vision – Overview Hanyang University Jong-Il Park
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Department of Computer Science and Engineering, Hanyang University Digital Image Processing Sampling & Quantization Image Enhancement Image Restoration Image Coding( or Image Data Compression) Image Understanding( or Computer Vision)
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Department of Computer Science and Engineering, Hanyang University Image formation
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Department of Computer Science and Engineering, Hanyang University Sampling & Quantization
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University Subsampling & aliasing aliasing
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Department of Computer Science and Engineering, Hanyang University Sub-Nyquist sampling H ½, v ½ Org. Circular Zone Plate aliasing
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Department of Computer Science and Engineering, Hanyang University Image Enhancement Goal to accentuate certain image features for subsequent analysis or for image display Input : imageOutput : image
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University Image Enhancement Techniques contrast/edge enhancement histogram equalization pseudo coloring noise filtering edge sharpening smoothing Applications processing of remote-sensed image via satellite radar, SAR, Ultrasonic image processing
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Department of Computer Science and Engineering, Hanyang University Image Restoration Goal to remove or minimize known/unknown degradations in image
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University Blur model estimate or recover f(x,y) from g(x,y) deconvolution problem
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Department of Computer Science and Engineering, Hanyang University Enhancement by integration
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Department of Computer Science and Engineering, Hanyang University Image Restoration Techniques deblurring noise filtering correction of geometric distortion inverse filtering Least mean square(Wiener) filtering Applications remote-sensed image processing noise cancellation
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Department of Computer Science and Engineering, Hanyang University Image Data Compression Goal to reduce the amount of data required to represent images Input : imageOutput : bit-stream data “010100101100110101001....” moving image: 1,000 1,000 8(bits/sample) 3 30 frame/sec = 72 10 7 bit/sec
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Department of Computer Science and Engineering, Hanyang University 2-D Image Compression, JPEG (a) 27.9 dB at 0.125 bpp(b) 31.5 dB at 0.25 bpp(c) 34.8 dB at 0.5 bpp Image quality by JPEG
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University 3D Mesh Compression Original ‘Bunny’ 12 bpc8 bpc10 bpc Model# of Vertex # of Triangle Original (byte) Compressed (byte) 12 bpc10 bpc8 bpc Bunny34835694732,879,78657,95237,64224,842 Compression ratio50 : 177 : 1116 : 1
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Department of Computer Science and Engineering, Hanyang University Image Data Compression Techniques Error-free coding( or lossless coding) Lossy compression Image Compression Standard JPEG, H.261, H.263, MPEG-1,2,4 etc Applications Transmission teleconferencing,TV system, remote sensing via satellite Storage VOD(video on demand), Video CD, DVD(digital video disk), medical imaging, educational and business documents
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Department of Computer Science and Engineering, Hanyang University Image Coding Standards
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Department of Computer Science and Engineering, Hanyang University MPEG MPEG-1 1992 Video CD Includes Audio Layer III (MP3) MPEG-4 Part 1: 1998 Part 2: 1999 (addition still under development) Audio visual object Mobile telephony (IMT-2000) Interactivity Content –Based Interactivity
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Department of Computer Science and Engineering, Hanyang University MPEG-7 2001 (addition still under development) Content Description Interface Metadata language and schemes for search & retrieval
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Department of Computer Science and Engineering, Hanyang University Content-based Image Retrieval Image retrieval Find similar images from image database Used features Color Texture Shape Query Retrieved
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Department of Computer Science and Engineering, Hanyang University Query Image Image Data List Retrieval Results Texture Option
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Department of Computer Science and Engineering, Hanyang University Video retrieval Scene change detection and key frame extraction Extracted key frame from a movie clip Content-based Video Retrieval
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Department of Computer Science and Engineering, Hanyang University Video retrieval Automatic indexing Index from a news sequence Content-based Video Retrieval
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Department of Computer Science and Engineering, Hanyang University Media Framework Tech. MPEG-21 All electronic creation, delivery and trade of digital multimedia content Transparent usage of various content types on various devices connected through various network
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Department of Computer Science and Engineering, Hanyang University Watermarking the process of embedding information into a host signal without changing perceived characteristics of the host
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Department of Computer Science and Engineering, Hanyang University Image Understanding Goal to interpret or describe the meaning contained in the image Input : imageOutput : interpretation(description) “KAISION” “circle”
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University Stereo Vision (disparity map) 기준 영상 ( 좌 ) 기준 영상 ( 우 ) 변위 참 값 ( 붉은색 : 가리워짐 ) 구한 변위 지도 ( 검은색 : 가리워짐 )
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Department of Computer Science and Engineering, Hanyang University ModelModel image Input scene Scene matching result Scene Matching (1)
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Department of Computer Science and Engineering, Hanyang University Model Input imageEdge image Scene matching result Scene Matching (2)
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Department of Computer Science and Engineering, Hanyang University – 크기, 반지름 Fruit Classifier Apple Orange Water Mellon
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Department of Computer Science and Engineering, Hanyang University – color
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Department of Computer Science and Engineering, Hanyang University Edge Detection
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Department of Computer Science and Engineering, Hanyang University Segmentation (a) Aerial Original Image(b) Segmented Image
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Department of Computer Science and Engineering, Hanyang University
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Department of Computer Science and Engineering, Hanyang University There are a lot of interesting topics to explore in image processing and computer vision.
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