4 ms·
Sure, as long as you have reasonably well-calibrated cameras and optics. Back-of-the-envelope calculation: assuming 1920x1080 camera sensors with a 90-degree h
by teraflop 8y ago
Sure, as long as you have reasonably well-calibrated cameras and optics.
Back-of-the-envelope calculation: assuming 1920x1080 camera sensors with a 90-degree horizontal field of view, each pixel covers a visual angle of approximately 0.001 radians. If you have two cameras separated by 5 feet horizontally, and your measurements are accurate to within a pixel, then you can measure the distance to an object 500 feet away with roughly 10% accuracy. That's a reasonably conservative following distance at typical highway speeds.
And that's just from a single parallax measurement. By using other visual cues (e.g. apparent size of an object whose physical dimensions are known) and averaging measurements across multiple frames, you can get a more accurate measurement.
- tomp 8y agoAh, I meant for humans. As in, how much is depth-perception actually necessary for driving... Obviously, humans also use higher-level cues, which IMO are much more important.
- teraflop 8y agoWhoops, my bad for skimming the comments and overlooking the context of your question. I found a page [1] that summarizes the level of visual acuity required to obtain a driver's license in each US state. It appears that all states will potentially issue a license to someone with vision in only one eye. Some states impose additional conditions, such as requiring a favorable report from an ophthalmologist, limiting the maximum speed, or restricting the driver to vehicles with outside rear-view mirrors (to compensate for the loss of peripheral vision on one side). [1]: http://lowvision.preventblindness.org/daily-living-2/state-vision-screening-and-standards-for-license-to-drive/ http://lowvision.preventblindness.org/daily-living-2/state-v...