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Khmer OCR           BarCamp     22nd September, 2012        LONG SeangmengLecturer and researcher, GIC - ITC     seangmeng...
Khmer OCR•   What is OCR?•   Khmer OCR Project•   State of the Art•   Khmer OCR System•   Project status•   Perspectives  ...
Optical Character Recognition (OCR) Text Image                  OCR  Editable Text                                      3
Khmer OCR Project• 2011• Team  –   Dr. SENG Sopheap, ITC  –   Mr. LONG Seangmeng, ITC5th  –   Mr. EN Sovann (doing master)...
State of the ArtAuthor                   Limitation                  ResultCHEY Chanoeurn, KOSIN    10 characters (បបបបប  ...
Khmer OCR System  Text ImagePre processingSegmentation Recognition                  សស ស ស សសស ស ស                      ស ...
Khmer OCR System (cont.)• Pre processing                        Binarization                        Noise removal         ...
Khmer OCR System (cont.)• Segmentation                       Page                   Line 1        Line                   L...
Khmer OCR System (cont.) • Recognition            Blob                              Training images (sample images) with l...
Khmer OCR System (cont.)• Recognition (cont.)   – How to find closest match?   – How to represent the blob image?       • ...
Khmer OCR System (cont.)• Post processing                        ស                                               Assemblin...
Project status• Pre processing   – Binarization and noise removal √   – Skew detection and correction X• Segmentation √• R...
Perspectives•   Joining characters•   Text layout•   Low quality text images•   Curve line                                13
Thanks for your attention! Demo & Questions???                             14
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Khmer OCR

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Khmer OCR

  1. 1. Khmer OCR BarCamp 22nd September, 2012 LONG SeangmengLecturer and researcher, GIC - ITC seangmeng@itc.edu.kh 1
  2. 2. Khmer OCR• What is OCR?• Khmer OCR Project• State of the Art• Khmer OCR System• Project status• Perspectives 2
  3. 3. Optical Character Recognition (OCR) Text Image OCR Editable Text 3
  4. 4. Khmer OCR Project• 2011• Team – Dr. SENG Sopheap, ITC – Mr. LONG Seangmeng, ITC5th – Mr. EN Sovann (doing master) – Ms. PRUM Sophea (doing PhD) – Mr. HAO Jeudi (year)• Develop a Khmer OCR system – Font independent – Size independent 4
  5. 5. State of the ArtAuthor Limitation ResultCHEY Chanoeurn, KOSIN 10 characters (បបបបប បបបប 92%Chamnongthai and PINIT ប)KumhomCHEY Chanoeurn, KOSIN 20 fonts 92.85% (size 22)Chamnongthai and PINIT 91.66% (size 18)Kumhom 89.27% (size 12)ING Leng Ieng and MUAZ Limon R1 22 98.88%AhmedKRUY Vanna Font and size independent 97% (manual preparation for new fonts)EN Sovann Font and size independent 96% (manual preparation for new fonts) 5
  6. 6. Khmer OCR System Text ImagePre processingSegmentation Recognition សស ស ស សសស ស ស ស ស សសPost processing Editable Text ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស 6
  7. 7. Khmer OCR System (cont.)• Pre processing Binarization Noise removal Skew detection and correction 7
  8. 8. Khmer OCR System (cont.)• Segmentation Page Line 1 Line Line 2 Vertical Symbol Blob 8
  9. 9. Khmer OCR System (cont.) • Recognition Blob Training images (sample images) with label Closest matchBlob to be recognized Image: Search for closest Label: ស match … 9
  10. 10. Khmer OCR System (cont.)• Recognition (cont.) – How to find closest match? – How to represent the blob image? • Fourier transform: Any function f(t) with period T can be written as Blob image => 2-D Fourier transform The blob image (B) represented by Fourier coefficients: B[0], B[1], B[2], … City block distance between two blobs B and B’: Distance = |B[0] – B’[0]| + |B[1] – B’[1]| + |B[2] – B’[2]| + … 10
  11. 11. Khmer OCR System (cont.)• Post processing ស Assembling ស Blob ស ស ស ស ស ស ស ស សស សស ស ស ស ស សស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស Reordering ស ស ស ស ស ស ស ស ស សស ស ស ស ស ស សស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស ស Spell Checking ស ស ស ស ស ស ស ស 11
  12. 12. Project status• Pre processing – Binarization and noise removal √ – Skew detection and correction X• Segmentation √• Recognition – Features extraction √ – Automatic generation of training data for new fonts √• Post processing – Assembling and reordering rules • Manual √ • Automatic X – Spell checking X• Performance evaluation X 12
  13. 13. Perspectives• Joining characters• Text layout• Low quality text images• Curve line 13
  14. 14. Thanks for your attention! Demo & Questions??? 14

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