Computer Vision Ronald Frazier CIS 479 April 20, 1999

Introduction Important area of studyImportant area of study –Ease of use for new users –Managing large quantities of images

Combines a Variety of Disciplines Standard Programming TechniquesStandard Programming Techniques Artificial Intelligence TechniquesArtificial Intelligence Techniques –Neural Networks –Fuzzy Logic Image Processing TechniquesImage Processing Techniques Human Biology and PhysiologyHuman Biology and Physiology

Optical Character Recognition (OCR) Converting graphical representation of text to character based representationConverting graphical representation of text to character based representation One of the most developed areas of computer visionOne of the most developed areas of computer vision Lots of ideas for further researchLots of ideas for further research

OCR - Character Recognition Examining graphical representation of character to determine character representedExamining graphical representation of character to determine character represented Identification ProcessIdentification Process –Apply image processing –Identify character (usually using neural networks)

OCR - Sample Character Recognition Algorithm Chaincode AlgorithmChaincode Algorithm –Apply image processing to get outline –Calculate average slope and curvature for each cell –Break character into 4x4 grid

OCR - Sample Character Recognition Algorithm Chaincode AlgorithmChaincode Algorithm –Data processed by Neural Network –Character recognized by Neural Network

Types of OCR Preprinted TextPreprinted Text Live HandwritingLive Handwriting

OCR - Preprinted Text Text that has already been written or typed before recognition beginsText that has already been written or typed before recognition begins –ex: Encyclopedia, Contract, Report Can be used on printed or handwritten documentsCan be used on printed or handwritten documents

OCR - Preprinted Text Recognition ProcessRecognition Process –Identify possible individual characters Standard character recognition techniquesStandard 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.Handle over 100 billion parcels yearly. Need automated way to identify destination of each parcel and print a barcode for faster processing.Need automated way to identify destination of each parcel and print a barcode for faster processing. For more details, see my web siteFor more details, see my web site

OCR - Live Handwriting Process text as it is writtenProcess text as it is written –ex: Personal Digital Assistants Can be used on handwritten documentsCan be used on handwritten documents Track time, direction, and angles of lines as they are written and use it to identify characterTrack time, direction, and angles of lines as they are written and use it to identify character

Content Based Image Recognition (CBIR) Identifying contents of imagesIdentifying contents of images ApplicationsApplications –Automated organization and classification of images –Image database searching –Still images or video

CBIR - Recognition Methods Content that can be recognized:Content that can be recognized: –Specific colors and approximate proportions ex: A lot of Red, a little bit of Greenex: 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 searchingStore video in database along with description of content for searching Automated determination of video contentAutomated determination of video content

Applications - News Video Recognition and Retrieval Processing TechniqueProcessing Technique –locate and extract on screen captions and closed captions –Apply OCR to convert captions to text

Applications - News Video Recognition and Retrieval Processing DifficultiesProcessing Difficulties –Interference from background image Handled by Frame Filtering and Frame ANDingHandled by Frame Filtering and Frame ANDing –Low resolution of captions Handled by magnifying characters and interpolating pixel valuesHandled by magnifying characters and interpolating pixel values

Other Possible Uses of Computer Vision RobotsRobots Self-Controlled VehiclesSelf-Controlled Vehicles Security - Fingerprint and Retina MatchingSecurity - 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:For more information on additional topics not covered in this presentation, along with links to other computer vision pages, see my web site at: