Camera Trainer: flickering and unstable detector with Bosch camera sensor mode at 30fps

Possible causes and solution(s)

Symptoms

A stability issue has been identified with the Bosch cameras when using a 30fps sensor mode. While the camera operates stably at 25fps, the performance deteriorates at 30fps, particularly in the context of an occupancy detection task using the Camera Trainer.

This behavior occurs specifically at 30fps and is not influenced by platform or firmware versions. Even if no changes in the scene occur, the counter continues to fluctuate.

Steps to reproduce the behavior:

Configure a Camera Trainer detector
Set up an Occupancy Task using the configured detector
At 25fps, the occupancy task provides stable and realistic results
At 30fps, even with the object present in the scene and no change in the environment, the occupancy counter toggles between 0 and 1

Causes

Given that a camera has an IVA image resolution of 640x640, which differs from the typical 640x360 resolution, when the camera operates at 30fps, this higher resolution leads to behaviors such as flickering and inconsistent detector.

Solution

Setting the debounce time for "Delay the alarm" can mitigate false alarms when a trained object is absent from the scene. This adjustment helps stabilize performance in some cases but is not effective for counter tasks, where the flickering of the object (caused by the high-resolution image at 30fps) leads to fluctuating counter values.

Use "Delay the Alarm": Adjusting the debounce time setting can help stabilize the occupancy task and reduce false alarms, but it will not resolve issues with counters. This setting is suitable for occupancy-based tasks but not effective in scenarios where accurate counting is crucial.
Use 25fps Mode: The most effective solution is to configure the camera to operate at 25fps, which provides stable performance for both occupancy detection and counter-based tasks. This frame rate avoids the performance limitations associated with the higher 30fps mode. note: the “Sensor mode“ (frame rate) setting is in the “Initialization“ menu, not in the stream config

Further changes to the camera's firmware to address this behavior would require significant alterations to the camera's architecture, which are currently not planned.

A mention of this limitation will be included in the Release Letter for users' awareness.