User manual

Processing Documents Preprocessing Images 31
Preprocessing Images
To improve OCR results, you can enhance your images before zoning and
recognition using the Image Enhancement tools.
Click the SET - Enhance Image button in the Image T
oolbar to open the Image
Enhancement window. This window has a starting image panel (1) on the left and a
result panel (2) on the right. Choose a tool (see following topics), then move sliders and adjust
controls (3). When the result is good, click Apply (4). Discard last change (5) or Discard all
changes (6) provide emergency exits. When you click Apply, the result image moves to the
left panel to become the new starting image for further enhancement. Changes are listed in the
History panel (7). When all changes are in order, click Page Ready (8) to have the next page
loaded or Document Ready (9) to finish enhancing.
We must distinguish three types of images:
Original image: The image created by your scanner or contained in a file before it enters the
program.
Primary image: The state of the original image after it has been loaded into OmniPage,
possibly modified by automatic or manual pre-processing operations.
OCR image: A black-and-white image derived from the primary image, optimized for good
OCR results.