Capacitive Touchscreen
User Manual H12 / SCAMAX® 8x1 - Version 2019.12
4.6.2.2.2. Dropout Setting 1-3
A more flexible method of color replacement is
achieved by processing accurately defined color
ranges. For this purpose, three separate Dropout
Settings are available, which may be configured
individually, but can be used in parallel.
For each of the Dropout
Settings, the applicable
color range is specified
through the configuration
screen shown to the left.
The mask pictured here is
graphically edited, becau-
se it exceeds the display
area of the touchscreen.
The uppermost field is
used to define the actu-
al
Dropout Color
. Besi-
des several pre-defined
hues (
Red
,
Yellow
,
Green
,
etc.) you may also select
Dominant Color
. This setting is helpful for detecting and removing interfering background colors, be-
fore further processing is performed.
Please note
- Should there be no background color, this function
might misinterpret colored text as being dominant - and possibly remove it!
Selecting
All Colors
as dropout color will remove any color from the image and only retain grayscale
information.
Selecting
User Color
will activate the color selec-
tion area, just below. Tapping this field will open
the color picker dialog (
you can use to precisely set a
Dropout Color
.
The slide controls in this section will limit the
function’s range of operation with regard to
color, saturation and brightness. The sliders will
assume different default settings, depending
on the selection made for
Dropout Color
. The
reason for this and the principle of operation is
best explained using the HSV color model. The
scanner processes color information according
to the color’s
hue
(
H
),
saturation
(
S
) and
bright-
ness
values (
V
), resulting in a device dependent
HSV color model. This model is represented by
the cone shown to the left. Any color will correspond to some
point, on or within the cone shaped volume. Whereas hues are
located along the rim of this cone and are represented by some
angle between
0
to
360
, the possible values for saturation and
brightness have finite limits of
0
and
255
. For each of these three
parameters, the Range - and Range + settings determine the
tolerances allowed, with respect to the selected dropout color.
This makes it possible to intentionally include image areas with
blended colors, or frayed border areas. For Saturation, the Ran-
ge - and Range + settings determine whether paler or more saturated shades of the dropout color
