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Computer Vision. Ronald Frazier CIS 479 April 20, 1999. Introduction. Important area of study Ease of use for new users Managing large quantities of images. Combines a Variety of Disciplines. Standard Programming Techniques Artificial Intelligence Techniques Neural Networks Fuzzy Logic
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Computer Vision Ronald Frazier CIS 479 April 20, 1999
Introduction • Important area of study • Ease of use for new users • Managing large quantities of images
Combines a Variety of Disciplines • Standard Programming Techniques • Artificial Intelligence Techniques • Neural Networks • Fuzzy Logic • Image Processing Techniques • Human Biology and Physiology
Optical Character Recognition (OCR) • Converting graphical representation of text to character based representation • One of the most developed areas of computer vision • Lots of ideas for further research
OCR - Character Recognition • Examining graphical representation of character to determine character represented • Identification Process • Apply image processing • Identify character (usually using neural networks)
Chaincode Algorithm • Apply image processing to get outline • Break character into 4x4 grid OCR - Sample Character Recognition Algorithm • Calculate average slope and curvature for each cell
OCR - Sample Character Recognition Algorithm • Chaincode Algorithm • Data processed by Neural Network • Character recognized by Neural Network
Types of OCR • Preprinted Text • Live Handwriting
OCR - Preprinted Text • Text that has already been written or typed before recognition begins • ex: Encyclopedia, Contract, Report • Can be used on printed or handwritten documents
OCR - Preprinted Text • Recognition Process • Identify possible individual characters • Standard character recognition techniques • determine possible words • Compare to dictionary and determine existing words • Select most likely existing word
Applications - U.S. Postal Service • Handle over 100 billion parcels yearly. • Need automated way to identify destination of each parcel and print a barcode for faster processing. • For more details, see my web site
OCR - Live Handwriting • Process text as it is written • ex: Personal Digital Assistants • Can be used on handwritten documents • Track time, direction, and angles of lines as they are written and use it to identify character
Content Based Image Recognition (CBIR) • Identifying contents of images • Applications • Automated organization and classification of images • Image database searching • Still images or video
CBIR - Recognition Methods • Content that can be recognized: • Specific colors and approximate proportions • ex: A lot of Red, a little bit of Green • Objects base on shapes, colors, textures, edges, size, etc. • Face detection
Applications - News Video Recognition and Retrieval • Store video in database along with description of content for searching • Automated determination of video content
Applications - News Video Recognition and Retrieval • Processing Technique • locate and extract on screen captions and closed captions • Apply OCR to convert captions to text
Applications - News Video Recognition and Retrieval • Processing Difficulties • Interference from background image • Handled by Frame Filtering and Frame ANDing • Low resolution of captions • Handled by magnifying characters and interpolating pixel values
Other Possible Uses of Computer Vision • Robots • Self-Controlled Vehicles • Security - Fingerprint and Retina Matching
Additional Information • For more information on additional topics not covered in this presentation, along with links to other computer vision pages, see my web site at: http://people.mw.mediaone.net/ldkronos/AI