Microscan EZ Match, User Manual

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EZ Match User’s Manual
Skew Correction
Line Speed
Distortion is corrected by shifting image rows in the direction opposite the symbol’s
movement on the line. The shift value of subsequent image rows is then increased. These
shift values depend on the speed of the line. The faster the line speed, the greater the
required shift values. More data loss is incurred at faster line speeds.
The image shown below was captured at a line speed of 40 inches per second, and it
shows virtually no inherent skew. The black area of the image is unusable, since the
information was lost as the symbol moved through the imager’s field of view.
The amount of data loss can be reduced by decreasing the image height or the row size of
the image, which reduces the amount of travel represented during the image frame
read-out. Note that the amount of distortion will not be changed, because the object will
have traveled the same distance during the read-out of the target area.
Definition: This feature is used to specify the line speed of the application, and it
determines how much distortion correction to apply. When enabled, this
feature will cause the overall decode rate to increase significantly. The timing
information in the table below is for a full megapixel image (1280 x 1024).
Note: Processing time decreases with larger image sizes.
Usage: < K537,line speed ,symbol direction>
Default: 0 (Disabled)
Options: 0 to 80 (inches per second)
Line Speed Additional Processing Time
10” / sec 69.5 ms
20” / sec 65.0 ms
30” / sec 62.5 ms
40” / sec 58.0 ms
60” / sec 55.0 ms
80” / sec 45.5 ms