OCROptical Character Recognition

Using

Digital Image Processing

K. Vijaya Krishna(06P71A0488)

Objective

To recognize alphabetic letters,numbers orother characters

which are in the form of digital images,without any human intervention

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications Computer vision - Automated guided

vehicles (AGV)

ALPR (Automatic License Plate Recognition)

Digital libraries

Personal digital assistants (PDAs)

Windows 7

Why not even in your Cellphones also

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications Computer vision - Automated guided

vehicles (AGV)

ALPR (Automatic License Plate Recognition)

Digital libraries

Personal digital assistants (PDAs)

Windows 7

Why not even in your Cellphones also

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications Computer vision - Automated guided

vehicles (AGV)

ALPR (Automatic License Plate Recognition)

Digital libraries

Personal digital assistants (PDAs)

Windows 7

Why not even in your Cellphones also

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications Computer vision - Automated guided

vehicles (AGV)

ALPR (Automatic License Plate Recognition)

Digital libraries

Personal digital assistants (PDAs)

Windows 7

Why not even in your Cellphones also

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications Computer vision - Automated guided

vehicles (AGV)

ALPR (Automatic License Plate Recognition)

Digital libraries

Personal digital assistants (PDAs)

Windows 7

Why not even in your Cellphones also

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Applications Computer vision - Automated guided

vehicles (AGV)

ALPR (Automatic License Plate Recognition)

Digital libraries

Personal digital assistants (PDAs)

Windows 7

Why not even in your Cellphones also

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Block Diagram

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Algorithms

• Template matching

• Image signatures

• Geometric features and

• Shape-based image invariants

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Template matching >Library Extraction >Pre processing

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Template matching >Library Extraction >Feature Extraction

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Template matching >RecognitionOCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Input

Template matching >Recognition >Preprocessing

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Threshold is calculated using Otsu's method,

which chooses the threshold to

minimize the intraclass variance of the thresholded black and white pixels.

Template matching >Recognition >Preprocessing

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Noise is filtered out by using standard methods like Dilation

imdilate(); Erosion

Imerode(); Opening

Imopen(); Closing

Imclose();

Template matching >Recognition >Feature Extraction

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

• Individual lines are isolated

• Individual Characters are identified

• And finally Compared with all the Template images (Correlation)

Template matching >Recognition >Feature Extraction

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Correlation

Template matching >Recognition >Recognition

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

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Template matching >RecognitionOCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Output

Economic Value

Proprietary software• Expervision• FineReader• Microsoft Office Document Imaging• OmniPage• Readiris• ReadSoft• SmartScore• And many more Mobile manufacturers

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Challenges >AccuracyOCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

A A A A A A A A A A AB B B B B B B B B B BD D D D D D D D D D D

Challenges >Accuracy >SolutionOCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

OCR TO ICR

Challenges >

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

References• Digital Image Processing

– Rafael C. Gonzalez & Richard E. Woods

• Handbook of Character Recognition and Document Image Analysis

– H. Bunke & P. S. P. Wang

• Image Recognition and Classification (Optical Science and Engineering)

– Bahram Javidi

OCRObjective

Applications

Block Diagram

Algorithms

Template Matching

Library Extraction

Preprocessing

Feature Extraction

Recognition

Preprocessing

Feature Extraction

Recognition

Economical Value

Challenges

References

Thank you

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