Datasheet

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Furthermore, the scan test window is equipped with advanced imaging fea-
tures to adjust the scanning to the color tones of the document.
Scanning in greyscale is in some instances necessary to obtain good OCR
results. When text is printed on a color background, scanning in color 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 background can
create “noise” that renders the recognition difficult or impossible! Think for in-
stance of black text printed on a dark background: when scanning such a docu-
ment in black-and-white, the user would not be able to “drop” the background
color without losing the text information as well.
Powerful intelligent routines automatically create a black-and-white version
for every greyscale image. Should this be necessary, the user can optimize the
image further for the consecutive OCR process with this command. In doing so,
a much larger range of documents becomes legible.
The recognition is re-executed promptly each time these settings are modi-
fied. The user is recommended to keep the greyscale image visible when he’s
adapting these parameters.
The option "Smoothen Image" renders the greyscale images more homoge-
neous by “flattening”, smoothing out relative differences in intensity. As a result,
a sharper contrast is created between the foreground - the text - and the back-
ground - a color, artwork etc. It is recommended that this option be enabled at all
times.
(A red or yellow background will never be picked up by the pen scanner: red
and yellow are the IRISPen’s “drop out” or invisible colors. This implies that all
text printed in red and yellow is illegible.)
The option "Brightness" influences the black-and-white threshold. The setting
"Automatic" determines the bilevel threshold automatically but with a great deal
of intelligence. The brightness is set automatically for all “normal” documents. A
different threshold is applied when necessary by darkening or lightening the black-
and-white image: when the image is darkened, more pixels become black in the
black-and-white version, when the image is lightened, less pixels become black.
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