Rockwell Automation 5370-OCR2 PAK - Manual (Page 41)

Chapter 5
Creating and Editing Fonts
5–6
The following are descriptions of the buttons on the Define Character panel.
Teach
Teaches the character pattern based on the image of the printed character
within the character box. Green and/or yellow pixels will be placed in the
character pattern, based on the setting of the Pixel Colors (see below).
The green and yellow pixels are placed by ”thinning” the image of the
printed character within the character box. The G+, G-, Y+ and Y- options
(see below) allow you to adjust the degree to which the image is thinned.
Thinning increases the tolerance of the system to variations around the edges
of the printed characters. See page 5–12 for a detailed description of the
thinning process.
Test
Tests the taught character pattern against the printed character(s) within the
OCR Tool window. The location and correlation percentage of each
character that correlates is displayed.
Characters that correlate at or above the set correlation percentage are shown
in green. These would be recognized by the OCR Tool.
Characters that correlate at or above 97.5% of the set correlation percentage
are shown in yellow. These would not be recognized by the OCR Tool,
however they are ”borderline” and minor changes to the image might cause
them to be recognized.
Characters that correlate at or above 95% of the set correlation percentage
are shown in red. These are also ”borderline” characters, but do not match as
closely as those shown in yellow.
Green Correlation
Score of 100% Yellow Correlation
Score of 94%
Red Correlation
Score of 92%
Threshold for E set at 96%