Rockwell Automation 5370-OCR2 PAK - Manual (Page 60)

Chapter 5
Creating and Editing Fonts
5–25
Eliminating Confusion
When a printed character correlates with two or more different taught
character patterns, it is called a confusion character. In general, confusion
between similar characters is reduced by placing more pixels in the areas of
the pattern where the characters differ, and fewer pixels in the areas of the
pattern where the characters are the same. This increases the significance of
the differences.
The following are some examples of pairs of characters that are sometimes
confused because they are similar in shape, and adjustments that may reduce
the confusion. In nearly all cases, large regions filled with yellow pixels
should first be thinned out, so that only the border remains.
•
B and 8
Confusion can be reduced by placing more green pixels in the upper-left
and lower-left corners of the B, as well as in the left-center region. Place
more yellow pixels in the corresponding regions of the 8.
•
C and O
Confusion can be reduced by placing more yellow pixels in the gap on the
right side of the C.
•
E and F
These some times get confused because the lower bar of a printed E may
fall in a region of the F pattern where there are don’t-care pixels. Make
sure that the F pattern has sufficient yellow pixels along the bottom.
•
I and B/D/E/F/H/K/L/M/N/P/R/T/U
In some fonts, the uppercase I is just a vertical line, which easily
correlates with parts of other characters containing vertical lines.
Confusion can be eliminated by placing sufficient yellow pixels to the
sides of the I pattern. It is also often necessary to increase the required
correlation percentage for the I character.
•
O and Q
The difference between O and Q is very minor in some fonts. It is
generally necessary to place as many green pixels as possible in the serif
of the Q, while still allowing for some variation of the character border. It
is also often necessary to reduce the number of green pixels in the circular
portion of the O and Q.
•
V and W
In some fonts, a printed W character may be incorrectly read as two V’s.
This problem can be eliminated by placing sufficient yellow pixels in the
upper-left and upper-right portions of the V pattern.