Datasheet

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USER'S GUIDE
In some instances, scanning in greyscale is mandatory to obtain good OCR
results! When text was printed on a color background, scanning in greyscale may
create the tone differences that are lacking in black-and-white images. When
there is only limited contrast between the text and the background, the back-
ground can create “noise” in black-and-white images that renders the recognition
difficult or impossible!
Think for instance of black text printed on a dark background: when scanning
such a document in black-and-white, you would not be able to “drop” the back-
ground color without losing the text information as well.
Thanks to its powerful intelligent routines, the IRISPen even solves tough
cases - here’s how our “difficult” image gets binarized!
Please note that the IRISPen handles changes - gradual and other - in the
background beautifully. To cope with varying colors and varying color intensity in
images, the binarization is “adaptive”. The software chooses the optimal black-
and-white threshold locally: a different threshold can apply to each small region
of the image.
3chapter2.p65 2/16/2001, 3:23 PM23