When you define a read strategy analytic for a Sharp camera, it optimizes how the camera captures license plate reads based on the expected vehicle speed and behavior.
Read strategies for fixed and mobile Sharp cameras
There are several scenarios where ALPR might be required. If vehicles generally pass the Sharp at the same speed, you can enable a read strategy to optimize ALPR performance for that scenario. For example, a mobile unit on a law enforcement vehicle must read license plates at a higher speed and frequency than a fixed unit used to control a gate. The read strategy analytic takes advantage of these differences to minimize duplicated and missed license plate reads. Each read strategy automatically configures the optimal internal values for the scenario.
- Slow-moving vehicle
- Select this strategy for fixed Sharp cameras monitoring parking lots and for mobile Sharp cameras used for parking enforcement. Generally results in better ALPR accuracy, but occasionally misses or duplicates plate reads.
- Fast-moving vehicle
- Select this strategy for fixed Sharp cameras monitoring highways and for mobile Sharp cameras used for law enforcement. This strategy obtains ALPR reads quickly, but often duplicates reads if the plate is in the field of view for a long time.
- Gate control
- Select this when vehicles must come to a stop when the license plates are read. For example, select this option for a SharpV camera that is monitoring a gated parking lot entrance or toll booth.
- Free-Flow
- Select this when AutoVu™
Free-Flow is
enabled on the ALPR Manager. This strategy improves the accuracy of the
parking lot occupancy calculation.NOTE: When using the Free-Flow read strategy, the system waits for the vehicle to exit the field of view before selecting the best plate read. You might notice a delay of a few seconds when monitoring live plate reads. For this reason, we do not recommend using this strategy when the camera outputs are also used to control a physical gates.
ALPR scenario | Slow moving vehicle | Fast moving vehicle | Gate control | Free-Flow |
---|---|---|---|---|
Mobile | ||||
Parking enforcement |
✔ |
|||
Law enforcement |
✔ |
|||
Fixed | ||||
Highways |
✔ |
|||
Parking lots |
✔ |
|||
Parking lots (AutoVu™ Free-Flow) |
✔ |
|||
Gate control |
✔ |
Read strategy characteristics
Characteristic | Slow moving vehicle | Fast moving vehicle | Gate control | Free-Flow |
---|---|---|---|---|
Missed plate reads | More frequent | Less frequent | Less frequent | More frequent |
Duplicated plate reads | More frequent | More frequent if plates are in the field of view for a long time. | Less frequent | Less frequent |
Latency | Medium-low | Low | Medium | High |
ALPR accuracy | Better | Good | Best | Best |