Yes, what you said is correct. Relying solely on computer vision to measure speed is not accurate. Its results can only be used as a reference.A long time ago I did some work on speed cameras where you didn't need to know the fixed distance between two spots, a purely optical point and shoot speed camera without laser or sonar.
If you look a an approaching vehicle in 1D/2D, the increasing width is non-linear and a known equation, therefore as long as its speed is constant you can work out its approaching speed by taking at least three photos at known time intervals. At the time suitable cameras with high enough resolution or the optics for a line scanner were too expensive so it never got completed. It got as far as measuring rough distances but the accuracy/resolution/consistency was nowhere near enough for measuring speed or vehicle dimensions.
Statistics: Posted by jiahaoli — Tue Dec 30, 2025 1:17 am