Determining appropriate image-processing settings

Because image enhancement is completed before page identification, you must set up the image-processing properties for all page types.

About this task

Most Datacap applications must manage multiple page types.
Important: Some special cases are exceptions to this statement. Rules complete multiple passes of image enhancement before or after page identification by using different settings for different page types or based on other criteria. The most common use case is a single pass before page identification. Any image enhancement that is completed before fingerprint matching must be identical to the image enhancement completed on the fingerprint template image when the template was created.

The default image-processing properties are designed to work with typical printed pages that use plain black text on a white background. One of the sample air ticket pages contains white text on a black background, which is the most difficult page to process. This procedure addresses first the page with white text on a black background.

Procedure

  1. In the Fingerprints pane on the Zones tab, expand the Flight class and select the third fingerprint (Airline #3).
  2. In the Image View pane, click Open image processing settings in the upper right.
  3. Click Run image processing to apply the default image-processing properties, as defined in the Properties pane.
  4. Click Reset image to revert to the original image.
  5. In the Properties pane, change the settings as follows:
    Category Property Default setting New setting
    Border Removal Border Removal True False
    Inverse Text Correction Minimum Area Width 300 100
    Line Removal Minimum Length 50 30
  6. Click Save and choose Save settings. Then, click OK.
    Attention: When you save the settings, Datacap saves the new image enhancement properties in the file C:\Datacap\TravelDocs\dco_TravelDocs\imagefix.ini. Datacap uses the same settings file for the image processing that takes place before page identification (ImageFix).
  7. Click Run image processing to apply the new image-processing properties. This time all of the vertical and horizontal lines disappear. The top of the page is not clipped, and the white text on a black background in converted to black text on a white background.
  8. Close the Image Processing window without saving the enhanced image.
  9. Next, in the Fingerprints pane, select the second air ticket fingerprint (Airline #2). There are problems on this page with the default settings, but you can try it with the new settings.
  10. In the Image View pane, click Open image processing settings in the upper right.
  11. Click Run image processing to apply the new image-processing properties.

    The horizontal lines are removed while everything else is intact.

  12. Close the Image Processing window without saving the enhanced image.
Parent topic: TravelDocs: Sample fingerprint image enhancement