User manual

Processing Documents Preprocessing Images 32
The input for Image Enhancement is the Primary image
This tool lets you switch between the Primary and the OCR image.
Some tools affect the Primary image, others the OCR image. Be sure you know which image
you are editing.
Good brightness and contrast settings play an important role in OCR accuracy
. Set these in the
Scanner panel of the Options dialog box or in your scanner’s interface. The diagram illustrates
an optimum brightness setting. After loading an image, check its appearance. If characters are
thick and touching, lighten the brightness. If characters are thin and broken, darken it. Use the
OCR Brightness tool to optimize the image.
Unsuitable
Tolerable
Good
Best
Good
Tolerable
Unsuitable
Image Enhancement tools
The Image Enhancement tools can also be used to edit primary images to save and use them as
image files. The following tools are accessible on the toolbar from left to right; their usage is
detailed as follows:
P - affects Primary image only.
O - affects OCR image only.
PO - can be applied to either the Primary or OCR image (or both)
P+O - a single action is applied to both the Primary and OCR image.