Milestone LPR 1.0 - Manual (Page 20)

Milestone XProtect
®
LPR 1.0 Administrator's Manual
www.milestonesys.com 20 LPR servers, sources and lists
o Character height: The height of characters (see "Character Height tab" on page 17) on
the recognized license plate (in percent).
o Confidence: The percent of confidence (see "Processing tab" on page 17) with which the
license plate has been recognized.
o Lists: The license plate list(s) (see "Working with license plate lists" on page 21) used to
recognize the license plate.
3. When done previewing/testing your LPR configuration, click Close to exit the Test Preview
window.
Your can use the previewer as many times as you like and on any LPR camera and with any
configuration you prefer.
Note that this view is only a live preview and only runs for five minutes. Furthermore, the settings used
for the preview are not saved until you exit the LPR camera Information window (see "LPR camera
settings" on page 14) and save them.
How to reduce CPU load in LPR
If your system is not configured correctly, running an LPR setup can easily result in heavy CPU load
on your LPR servers. The following guidelines can help you reduce your CPU load to an acceptable
level.

Set video resolution as low as possible, still keeping license plates clearly visible. Use the
XProtect Corporate or XProtect Enterprise's Management Client or Managemement
Application (the Settings tab of the relevant LPR camera).

Reduce video frame rate to match the traffic speed. This is done by limiting the processing
frame rate in the LPR camera configuration. Use the XProtect Corporate or XProtect
Enterprise's Management Client or Managemement Application (the Settings tab of the
relevant LPR camera).

Set as small a recognition area as possible. And ensure that static high contrast areas
(especially containing text) are not included in the recognition area. Use the the Complex area
option (see "Recognition Area tab" on page 15).

Minimize the difference between minimum and maximum character height. Use the Character
Height (see "Character Height tab" on page 17) tab.

Play around with the processing options and closely follow the effect of what you are doing on
the CPU load of the relevant LPR machines. Use the Processing tab (on page 17).

Try the following to quickly verify your changes:
Run the test preview (see "Test current LPR configuration" on page 19) with, for example:
o leaves moving in the wind
o traffic or people moving
o a parking sign or similar
o complex structures of some kind (a design pattern or similar)visible in the picture. Check
the CPU load of the LPR server(s) with this setup. Next, optimize the setup by eliminating