Panasonic IMAGECHECKER PV230 Manual page 22

Set the minimum and maximum limits so that the target characters for "Segment preprocess filter" can be
extracted checking the segmentation results.
Refer to Chapter 4.6.2 in the PV200 User's Manual for the details of setting procedure.
Auto
A method to automatically binarize based on the brightness in the inspection area.
Use it when unevenness of brightness is less in the inspection area and the brightness of whole image varies
every time the inspection is executed.
1.
Select "Auto" in "Threshold method".
2.
Select "Light" or "Dark" in "Background (Automatic)".
Specify whether the background is lighter or darker than characters.
In case of the right figure, when the upper white characters are inspected,
select "Dark" because the background is darker than the characters.
When the lower black characters are inspected, select "Light" because
the background is lighter than the characters.
3.
Execute Segment with the F2 key, and check the displayed segmentation result.
When the target characters cannot be cut out, also use "Segment pre-process filter" mentioned in the next
page for the adjustment.
Reliable segmentation can be performed when there is a possibility that the brightness of a whole
image will change.
20
Binarized as follows;
Dark parts are characters -> Black
Light parts are backgrounds -> White