UNSD Regional Workshop on Census Data Processing for the English speaking African Countries: Contemporary technologies for data capture, methodology and practice of data editing

1
Optical Data Capture Optical Character
Recognition (OCR) Intelligent Character
Recognition (ICR) Intelligent Recognition
2
Summary

• Concept/Definition
• Forms Design
• Scanners Software
• Storage
• Accuracy
• OCR/ICR Advantages and Disadvantages
• Intelligent Recognition (IR)
• Commercial Suppliers

3
Definition/Concept of OCR

• Gives scanning and imaging systems the ability to
  turn images of machine printed characters into
  machine readable characters.
• Images of the machine printed characters are
  extracted from a bitmap of the scanned image

4
Definition/Concept of ICR

• Gives scanning and imaging systems the ability to
  turn images of hand written characters into
  machine readable characters
• Images of the hand written characters are
  extracted from a bitmap of the scanned image

5
OCR and ICR Differences

• OCR is less accurate than OMR but more accurate
  than ICR
• ICR will require editing to achieve high data
  coverage

6
Forms

• OCR/ICR has less strict form design compared to
  OMR
• No timing tracks
• Has Registration Marks
• ICR requires hand printed boxes filled one
  alphanumeric character per box

7
OCR

• Forms
• OCR/ ICR is more flexible since
• no timing tracks are required
• The image can float on a page
• The use of drop color reduces the size of the
  scanners output and enhances the accuracy
• ICR/OCR technology often uses registration mark
  on the four-corners of a document, in the
  recognition of an image

8
(No Transcript)
9
OCR/ICR Scanners and Software

• Forms can be scanned through a scanner and then
  the recognition engine of the OCR/ICR system
  interpret the images and turn images of
  handwritten or printed characters into ASCII data
  (machine-readable characters).
• Users can scan up without doing the OCR
• Speeds Range from 85-160 sheets/min (dependent
  on the recognition engine)

10
OCR/ICR Storage Characteristics

• Storage/Retrieval
• Images are scanned and stored and maintained
  electronically
• There is no need to store the paper forms as long
  as you safeguard the electronic files
• With OCR/ICR technologies, images can be scanned,
  indexed, and written to optical media

11
Ideal OCR/ICR Accuracy Thresholds

• Accuracy
• Accuracy achieved by data entry clerks (99.5)
  are approximately equal to OCR/ICR in in perfect
  tuning (99.5)
• Up to 99.9 accuracy with editing (like OMR)
• The recognition engine must be tuned, tested and
  validated very carefully

12
OCR/ICR Advantages

• Advantages
• Recognition engines used with imaging can capture
  highly specialized data sets
• OCR/ICR recognize machine-printed or hand-printed
  characters.
• Scanning and recognition allowed efficient
  management and planning for the rest of the
  processing workload
• Quick retrieval for editing and reprocessing

13
OCR/ICR Disadvantages

• Technology is costly
• May require significant manual intervention
• Additional workload to data collectors -ICR has
  severe limitations when it comes to human
  handwriting
• Characters must be hand-printed/machine-printed
  with separate characters in boxes
• ineffective when dealing with cursive characters

14
OMR-OCR/ICR Compared
15
OCR/ICR Challenges/Issues

• Has corresponding issues with OMR
• Algorithm development (Preparation of memory
  dictionary)
• Processing time considerations due to recognition
  engine
• Development costs

16
Definition/Concept of IR

• State of the art recognition technology
• Gives scanning and imaging systems the ability to
  turn images of hand written and cursive
  characters into machine readable characters
• Images of the hand written and cursive characters
  are extracted from a bitmap of the scanned image
• The ability to capture cursive make this method
  unique

17
Definition/Concept of IR

• eight elements that make up the trajectories of
  all cursive letters (figure 1)

Photo Parascript LLC
18
Definition/Concept of IR

• Intelligent Recognition dynamically uses context
• context is used during the recognition process,
  improving the accuracy of results
• Contexts helps to identify letters where the
  symbol segmentation of an image is ambiguous

Photo Parascript LLC
19
Technology Evolution
FORM TYPES
TEXT STYLES
No special form design
No constraining boxes or combs
Condensed strings
Cursive
Dirty Noisy forms
Bad quality paper
Legacy Forms
Bad quality machine print
Unconstrained Handprint
Specially designed for automatic recognition
Constrained Handprint
Constraining boxes or combs
Drop out ink for preprinted text boxes
Machine Print
Intelligent Recognition
OCR
ICR
TECHNOLOGY EVOLUTION
Illustration Conference on Technology Options
for 2011 Census
20
Major Commercial Suppliers

• Top Image Systems (TIS) (http//www.topimagesystem
  s.com)
• ReadSoft (http//www.readsoft.com)
• Teleform (http//www.intelliscan.com/TeleForm1.htm
  )
• Scanner Suppliers
• Fujitsu, Canon, Bell Howell, Kodak

21
THANK YOU!