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GETTING STARTED…
4
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8024172/V3-0/2021-01
Subject to change without prior notice.
Operating instructions | LABEL CHECKER P6XX
4.8.4
Thresholding method
Manual threshold
Sets the threshold in selecting the pixels, depending on their intensity (brightness).
According to the option “White on black” or “Black on white”, the lighter/darker pixels
than the threshold will be selected.
Adjusting of hysteresis threshold will filter out any pixels with undesirable intensity.
All pixel of a region fulfills the condition and are kept as potential characters. This method
is not suitable for changing the light condition, only for stable light condition.
Threshold (intensity) – The manual threshold selects the pixels from the input
image, whose gray values are lower than the selected threshold.
Local threshold
The local threshold segments an image to smaller parts according to the set mask size
and adjust the threshold for each segment dynamically. Automatically determines the
threshold for each pixel from OCR/OCV region based on its surroundings:
Mask size x Mask size
Local threshold mask size - Size of neighborhood in which the local threshold is
calculated.
Auto threshold
The auto threshold segments an image determined from its histogram. The threshold
level automatically adjusts the contrast between the characters, the background,
including each character (locally). Threshold computation is based on the entire OCR/OCV
region.
Changing the character surroundings affects the value of the threshold.
Enabling the auto threshold will automatically adjust the settings. You only need to click
the capture image.
You will notice that when the Auto threshold is selected, the threshold slider will be
invisible and you will not be able to adjust the threshold.
The auto threshold can be slower in reading, but highly recommended for inconsistent
image samples and complicated backgrounds.