Axis P1346 Installation Manual page 17

24. High Conf Max: This determines the maximum number of characters that must
be found for the LPR Engine to return as a possible plate. If the LPR Engine
finds a character string longer than this value, it assumes it has a misread. This
includes the space in the middle of the character set. This includes the space in
the middle of the character set. If there is a plate read over this value, it will not
be recorded. Ideal Setting is 9.
25. Use Background Segmentation: This determines whether or not the system use
motion detection to trigger plate reads. If background segmentation is on, motion
is required to wake up the system. This should normally be on unless tuning is
being done with a reference object that is stationary in the camera field of view.
If background segmentation is off, the LPR engine evaluates every image
whether it has motion or not.
26. Scale: For background segmentation, the image can be scaled before it is
processed for motion. Scale of 1 means no scaling. Sometimes for large, high
resolution images, it is necessary to scale the image down to improve
performance. Scale of 0.4 means scale the image to 40% of its original size
before analysis.
27. Box Size: The minimum size of a rectangle in the image which will be returned as
motion. For instance, if motion is detected in a rectangle that is 100 pixels wide
and 50 pixels high, Box Size must be at least 5000 (1000x50) or this area won't
be returned as motion. Larger box sizes increase performance but don't see
objects at a great distance. Ideal setting is 7500.
28. Burn Rate: Determines how quickly an object that comes into the foreground
becomes part of the background and is no longer seen as a foreground object
with motion. Slow burn rates generate lots of motion and analyze the image
more times. High burn rate lets a car come into the field of view and if at a stop
sign, ceases analyzing the vehicle after a short period of time as the car
becomes part of the background (no motion). Ideal setting is 0.1.
29. Threshold: Tuning parameter for increasing contrast between light and dark
pixels. Any pixels with a color value below this are dropped to zero. Ideal setting
is 25.
30. Pre-Erode: Number of iterations to "erode" the image before dialation. Rarely
should this be changed.
31. Dialate: Number of iterations to "dialate" the image. Rarely should this be
changed.
32. Post-Erode: Number of iterations to "erode" the image after dialation. Rarely
should this be changed.
LPR Setup and Field Installation Guide
ipConfigure ESM 5.1
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