Requirements for the operation of the stopped object detector are the following:
| Object images | - The detected object must be clearly distinguishable by the human eye.
- Width and height of objects in the image must not exceed 75% of the frame size.
- The minimum width or height of an object must be at least 5% of the width/height of the frame.
- The image isn't noisy and isn't distorted by the artifacts of the compression algorithm.
- The duration of the object visibility is at least 6 frames.
- Between two neighbor frames, an object must move in the direction of a distance not exceeding its size. This condition is necessary for the correct calculation of the object track.
- The minimum value of pixel density per meter is observed:
| Image resolution | Object type | Minimum pixel density per meter (ratio of |
|---|
|
the | object width in pixels to |
|---|
|
the | object width in meters) | Minimum object size in pixels, width x height | Ratio of |
|---|
|
the the | frame width as a percentage |
|---|
| 1920x1080 | Human | 55 | ~25x105 | ~3% | | 1280x720 | Human | 35 | ~17x70 | ~3% | | 640x360 | Human | 17 | ~10x42 | ~3% | | 1920x1080 | Light vehicle
(2 axles) | 55 | ~354x300 | ~20% | | 1280x720 | Light vehicle
(2 axles) | 35 | ~240x205 | ~20% | | 640x360 | Light vehicle
(2 axles) | 17 | ~132x112 | ~20% |
|
