Capacitive Touchscreen
User Manual H12 / SCAMAX® 8x1 - Version 2019.12
After increasing the
Contrast
level to 100, only
the darkest shades of gray are interpreted as
foreground information. Everything else is con-
sidered background and removed.
The
Outlining
function is based on edge de-
tection and changes the way filled areas are
treated, during binarization. In order to illustrate the function’s
operation, we’ll use our company logo as an example. The InoTec
logo (
left
) is composed of adjacent white, black and red areas.
The default
Outlining
setting of 50 suppresses all red areas, only
the boundaries around them remain. As a result, the logo’s over-
all appearance is preserved. Please note how the white letters
in the lower logo area have been surrounded with black pixels,
in order to ensure legibility.
When reducing
Outlining
to 0, all solid black areas are removed,
too. This includes the insides of the large black letters, so only
their contour is reproduced. In spite of these drastic changes,
the logo’s shapes and lettering can still be fully recognized.
After increasing the
Outlining
level to 100, the shape on the left
side of the logo is no longer recognizable and the lower logo
area has been solidly filled.
The operation of
Pixel Filter
is very similar to
how a despeckle function works. However, whe-
reas despeckle is used to remove isolated pixels or small clusters of pixels
from bitonal images,
Pixel Filter
is applied to grayscale images, before bi-
narization. This approach improves readability of darker or smudged do-
cuments and also minimizes the risk of destroying any image content
(
letters, numerals
).
As an example, please consider the image
shown to the left. We have chosen a document
with light gray/smudged background and dark
gray (
not black
) lettering. As a result, the co-
lor difference between background and text is
alarmingly small, in some areas of the image.
When converting this image to bitonal with
standard settings and
Pixel Filter
turned off (
No
Filter
), readability is clearly impaired due to the
high amount of noise (
pixels
) appearing in the
text’s background.
Applying a
Light Filter
(default) will improve
conversion quality appreciably, resulting in
much better text readability.
