Improving OCR accuracy involves optimizing scanned documents through pre-processing and cleanup. Pre-processing includes using adequate spacing, limiting lines and colors, and OCR-friendly fonts. During scanning, images should be cleaned up through techniques like adaptive thresholding, despeckling, and removing blank pages. Intelligent capture solutions like ImageRamp can enhance images for improved OCR accuracy through settings validation and optimization. Proper document handling and cleanup can be as important as scanning technologies for achieving high OCR accuracy needed in applications like healthcare and legal.

1. Improving OCR Accuracy
Clean UpandEnhance Scanned Images

2. Cleaner Image = More Accurate OCR

3. Your acceptable level of OCR
accuracy may depend on your
application

4. Healthcare and Legal applications have high
OCR accuracy requirements.

5. Pre-
Scanning
During
Scanning
Optimizing for the highest OCR
accuracy generally is divided into two
phases.

6. Form Design
• adequate white
space
• limited lines
Font Selection
• monospace like
Courier or san serif
fonts like Helvetica
• at least 10-13
points
Color Selection
• limited use of color
Set pre-processing standards and
procedures

7. During scanning…
Scan at
at least 300 dpi
and CLEAN.

8. Most capture applications
include basic cleaning features.

9. Go beyond the basics with DocuFi’s

10. Adaptive thresholding assists in cleaning “dirty” documents or documents with
a colored background which interferes with the foreground data.
Adaptive Thresholding

11. Adaptive thresholding assists in cleaning “dirty” documents or documents with
a colored background which interferes with the foreground data.
Adaptive Thresholding
Most scanner and capture software can apply basic thresholding technology.

12. Adaptive Thresholding
ImageRamp uses Adaptive Thresholding with advanced algorithms and
Sensitivity settings allowing you to optimize the thresholding for your
documents.

13. This option smoothes the edging of text. Smoothing text fills small pits in the
edges of a character and removes small bumps on the edges. This improves
legibility and reduce storage needs.
Smooth Text

14. Dither Form Fills
Black and white printed images may use dithering, often called dot shading, to
simulate shades of gray by varying the patterns of dots. The Dither Form Fills
feature removes areas of dot shading from an image. This function is used to
make a black and white TIFF image appear as black and white and not a
grayscale image.

15. This searches and resizes the document based on the outermost located raster
data or pixels.
Reset Margins

16. Using detected text as the basis for alignment, this tool is designed to work with
scanned office documents and eliminate rescans.
Deskew or
Straighten Page

17. This selection detects and removes lines which may interfere with OCR
interpretation.
Remove Lines

18. Whether your scanned image is contaminated or a bad original, this option
removes extraneous black specks and fills in white holes on black areas of an
image.
Remove Noise or
Despeckle

19. Auto Rotate automatically evaluates orientation based on the text and rotates
misoriented pages. Optionally, select a degree of rotation for ImageRamp to
rotate all pages based on the selection.
Auto Rotate and
Rotate Pages

20. This can be used to eliminate unnecessary blank pages in a document and make
the file size smaller. Blank page detection can also play a role in file splitting.
Many users divide documents in a scanning stack with blank pages and
ImageRamp can be set to split the stack of documents into multiple files when
blanks are detected.
Remove Blank
Pages

21. Besides cleaning and enhancing
the image, ImageRamp has other
ways to improve OCR accuracy.

22. OCR with validation during processing is a very powerful way to
eliminate entries not meeting a specific format rule.
For instance if an inventory item should contain three alpha
characters followed by five numbers, all documents with item
numbers that are not identified in the OCR process with that pattern
may be tagged for manual inspection before further processing is
done.
Field Validation Improves Accuracy.
PEN21096
CAP36581
INV98453
PA568793

23. ImageRamp offers
significant preview and
testing options to fine-
tune settings.
Additionally
ImageRamp offers PDF
or TIFF output which
may differ in OCR
accuracy.

24. Set Pre-
Processing
Standards
OCR
Accuracy
Scan at
300+ dpi
Capture with
Clean-up
Wrap up: Ways to
Improve OCR
3

25. Pre-Processing Standards
Encourage accuracy by setting document procedures
and guidelines to:
Good pre-processing can be as important as the scanning technologies.
• Use adequate white space
• Limit lines and gridlines
• Limit the use of color
• Use OCR friendly fonts and sizes

26. Use an Intelligent Capture
Solution such as ImageRamp

27. Learn More about Document Imaging and Capture

28. For more on:
• Clean scans,
• Ways to improve OCR
scanning,
• Cleaning documents for
scanning,
• Enhancing your images for
improved OCR,
• Watching folders,
• Batch Processing,
• Bulk scanning,
• Split files with barcodes,
• Barcode splitting,
• Docufi,
• Imageramp,
• Watch folders,
• Data capture,
• Intelligent Data Capture
Contact Us
DocuFi
30 years’ experience in the Document Imaging market.
Capture Products www.docufi.com
ImageRamp Cleanup and Enhance for OCR
Copyright ©2014
makers of ImageRamp,
Document Management
Capture Solution

29. Image Credits
• Tim Evanson, “Albert V Bryan Federal District
Courthouse - Alexandria Va - 0014 - 2012-03-10”,
http://bit.ly/1iGIBpF
• takacsi75, “Medicine 02”, http://bit.ly/1dtsIxK
• ToastyKen,”New Mophead”, http://bit.ly/1ijjkkD
• mjtmail (tiggy), “Day 307”, http://bit.ly/1g4G3Bw