What is intelligent video analysis: border crossing, area intrusion, items left behind

Common algorithms

What the effect depends on

Algorithmic capability is only the basis, and the actual effect is mainly determined by the following factors:

1. Target pixel size: The target must be at least 40×40 pixels in the screen. If it is too small, the detection rate will significantly decrease.
2. Installation Angle: When the depression angle is too large (>45°), the targets will seriously block each other and the detection rate will decrease.
3. Light stability: Frequent light and shadow changes (tree shadows, car lights, water reflections) are the main source of false alarms.
4. Rule area settings: If the area is too large and the boundary is close to the edge of the screen, false alarms will increase.
5. Target density: When the crowd is highly dense, the detection accuracy will decrease significantly.

Deployment recommendations

• First use actual scene recording to verify the algorithm instead of just watching the demonstration video.
• Testing in different time periods: testing during the day, night, backlighting, rainy days, and peak hours.
• The rules area avoids trees, water, billboards and other easily moved areas.
• Link with the business system to clarify the handling process after the alarm, otherwise the alarm will be ignored.
• Reserve a tuning cycle, which usually requires 2 to 4 weeks of on-site iterations.

Reasonable expectations

Intelligent analysis is a auxiliary means rather than a replacement for manual work.Under the premise of standardized installation and sufficient tuning, Controlling false negatives to a low level and reducing false positives to an acceptable range are realistic goals; pursuing "zero false positives and zero false negatives" is not practical.