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Projects. CS 661. DAS 02, Princeton, NJ. OCR Features and Systems Degradation models, script ID, Bilingual OCR, Kannada OCR, Tamil OCR, mp versus hw checks, traffic ticket reading Handwriting Recognition Stochastic models, holistic methods, Japanese OCR Classifiers and Learning
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Projects CS 661
DAS 02, Princeton, NJ • OCR Features and Systems • Degradation models, script ID, Bilingual OCR, Kannada OCR, Tamil OCR, mp versus hw checks, traffic ticket reading • Handwriting Recognition • Stochastic models, holistic methods, Japanese OCR • Classifiers and Learning • Multi-classifier systems • Layout Analysis • Skew correction, geometric methods, test/graphics separation, logical labeling • Tables and Forms • Detecting tables in HTML documents, use of graph grammars, semantics • Text Extraction • Indexing and Retrieval • Document Engineering • New Applications • CAPTCHA, Tachograph chart system, accessing driving directions
ICDAR 03, Edinburgh, UK • Multiple Classifiers • Postal Automation and Check Processing • Document Understanding • HMM Classifiers • Segmentation • Character Recognition • Graphics Recognition • Non-Latin Alphabets- Kanji/Chinese, Korean/Hangul, Arabic/Indian • Web Documents, Video • Word Recognition • Image Processing • Writer Identification • Forms and Tables
Control Panel Query Input Query Result Telugu and Arabic modules under development
Text/Image Separation Intervals between peaks
Line Separation • Ascenders & descenders interfering with lines • Region-growing approach • In Devanagari, single word is a single connected component • Grow regions using horizontally adjacent components
Word Separation • In Devanagari, all characters in a word are glued together by Shirorekha • Vertical Projection profile easily separates words
Structural FeaturesBAG End Loops Junction End Loop Turns
Feature Extraction and Ordering Critical node: removal disconnects a connected component. Loops End End Turns Junction Turns Loop 2-degree critical nodeskeep feature ordering from left to right. Right Component Left Component
Fingerprint Recognition Orientation maps and minutiae detection
Preprocessing Operations • Image Enhancement • Image Segmentation • Correlation among fingers Filtering
Combination and Dynamic Selection [Govindaraju and Ianakiev, MCS 2000] image WR 1 WR 3 + 1 Top 50 Lexicon <55 WR 2 Top 5 • Optimization problem • Combinatorial explosion in • arrangement of recognizers • lexicon reduction levels
Lexicon Density [Govindaraju, Slavik, and Xue, IEEE PAMI 2002] Lexicon 1 Lexicon 2 Me MeHe MemoSo MemoryTo MemoirsIn Mellon
Handwriting Recognition Ranked Lexicon Context
Multiple Choice Question Ranked Lexicon Context
Interactive Models [McClelland and Rumelhart, Psychological Review, 1981] ABLE TRAP TRIP Words A T N Letters Features
“CAPTCHAs”:Completely Automated Public Turing Tests to Tell Computers & Humans Apart • challenges can be generated & graded automatically (i.e. the judge is a machine) • accepts virtually all humans, quickly & easily • rejects virtually all machines • resists automatic attack for many years (even assuming that its algorithms are known?) NOTE: the machine administers, but cannot pass the test! L. von Ahn, M. Blum, N.J. Hopper, J. Langford, “CAPTCHA: Using Hard AI Problems For Security,” Proc., EuroCrypt 2003, Warsaw, Poland, May 4-8, 2003 [to appear].
Yahoo!’s present CAPTCHA: “EZ-Gimpy” • Randomly pick: one English word, deformations, degradations, occlusions, colored backgrounds, etc • Better tolerated by users • Now used on a large scale to protect various services • Weaknesses: a single typeface, English lexicon
Hard biometrics Soft biometrics Face Eye :Retina & Iris Fingerprint Hand Geometry Handwriting Speech DNA Age Ethnicity Nationality Build Gait Mannerisms Writing style (Semantic) Fields PR Statistics NLP Cog Sc Ontology Anthropometry Sociology Vision Digital Lib AI Law The Biometrics Spectrum Derived biometrics Indirect biometrics Text/News WWW Driver’s License Medical Records INS Forms • Biometric Consortium (www.biometrics.org) lists several products: • Faces (30); Fingerprints (50); Hand geometry (30); Handwriting (5); Iris (5); Multimodal (6); Retinal (2); Vein (3); Voice (22); Other (20) • NONE on soft biometrics • NONE on the fusion of indirect and derived biometrics
NYS EMS PCR Form NYS PCR Example Thousands are filed a day. Passed from EMS to Hospital. PCR Purpose: • Medical care/diagnosis • Legal Documentation • Quality Assurance EMS Abbreviations • COPD Chronic Obstructive Pulmonary Disease • CHF Congestive Heart Failure • D/S Dextrose in Saline • PID Pelvic Inflammatory Disease • GSW Gunshot Wound • NKA No known allergies • KVO Keep vein open • NaCL Sodium Chloride