InoTec SCAMAX H12, Руководство пользователя

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Capacitive Touchscreen User Manual H12 / SCAMAX® 8x1 - Version 2019.12
Page 61 of 136
of images, which would otherwise be rotated according to the front.
4.6.3.5. Deskew
In the Deskew screen
the skewness correction
for the output images is
activated and configu-
red.
In addition to straigh-
tening up images, the
Deskew function will
also perform black bor-
der removal. Furthermo-
re, it will automatically
extend the scan area, if
necessary, in order to avoid cropping document corners when images need to be rotated by larger
degrees. This mechanism ensures that scanning can be performed without image loss at rotation
angles of up to 22°, with the scanning resolution set to 300 dpi. Higher scanning resolutions will
reduce this range. With
Deskew
turned off, the scanning area will be strictly limited to the document
format specified.
4.6.3.5.1. Edge Threshold
Prior to deskewing and black border removal,
the document’s edges need to be detected. This
is done by comparing brightness levels of scan background and document. Use the slider to set the
desired threshold level. The default value of 100 reliably work with most common scan templates.
With unusually dark documents lowering the threshold value and when using Gamma Correction ( see
chapter 4.6.2.1.2. ) increasing the threshold value will help very often.
4.6.3.5.2. Deskew Fill Color
Although the
Deskew
function will automatical-
ly extend the scan area in order to reduce the
chance of lost corners, this might still happen in extreme cases. Resulting empty image areas may be
filled with any desired color. Tapping the color field will open a color picker dialog ( see chapter 4.2.2. )
to define the desired fill color. Please note that this function will not fill areas which were already
missing from the physical document ( such as torn or cut off areas ).
4.6.3.5.3. Advanced Settings
If option
Advanced Settings
remains unchecked,
all its parameters will still be applied, but with
default values. The default
values for the two slide
controls at the top are dy-
namically controlled by the
setting for Edge Threshold
( see chapter 4.3.1.5.1. ) and
will change accordingly.
Brightness specifies the threshold above which edge detection will commence and is set at 50% of
the value for Edge Threshold.
Trend Threshold
specifies the rate of change which the edge detection
value needs to reach, after it has exceeded the Edge Threshold level, before an object is considered to
be an edge. Trend Threshold defaults to 25% above the Edge Threshold value. Under normal circum-