Is There A Camera That Measures Distance

Question 1

I take the question has been answered fairly (with the obvious caveats of requiring level basis and possible accuracy issues) only for those who don't believe it can be washed or that it needs a video camera, let me explain the low-level math needed to do it....

alt text

The picture above shows me standing outside my firm. The horizontal (d) is the distance I want to measure and the vertical (h) is the height in a higher place the basis at which I'm property the camera. In this example 'h' is a known value when I'g holding the android camera at middle-level (approx 67 inches or 1.7 metres). When I tilt the photographic camera to aim it directly at the point my house meets the ground, all the software needs to practice is piece of work out the angle (a) relative to vertical and it can calculate 'd' using...

                d = h * tan a

Question 2

Well yous should read how ithinkdiff.com "measures" the distance:

Uses the angle of the iPhone to gauge the distance to a signal on the ground. Agree the iPhone in forepart of you, align the point in the camera and get a directly reading of the distance. The altitude tin then be used in the speed tool.

Then basically information technology takes the height of where you agree the phone (eye-level), and so you lot must point the camera to the signal where object touches the footing. Then the phone measures the inclination and with uncomplicated trigonometry it calculates distance.

This is of course not very accurate. It gets less accurate the farther the object is. Also it assumes that the ground is level.

SquonkSquonk 48.3k 18 gold badges 101 silverish badges 135 bronze badges · Accepted Answer · 2011-01-04 00:23:38Z

I take the question has been answered fairly (with the obvious caveats of requiring level basis and possible accuracy issues) only for those who don't believe it can be washed or that it needs a video camera, let me explain the low-level math needed to do it....

alt text

The picture above shows me standing outside my firm. The horizontal (d) is the distance I want to measure and the vertical (h) is the height in a higher place the basis at which I'm property the camera. In this example 'h' is a known value when I'g holding the android camera at middle-level (approx 67 inches or 1.7 metres). When I tilt the photographic camera to aim it directly at the point my house meets the ground, all the software needs to practice is piece of work out the angle (a) relative to vertical and it can calculate 'd' using...

                d = h * tan a

Sextant is a device utilize to summate height of whatever object. May be it help — November 27, 2014 at 6:46
@NicolasTyler the presented draw is correct, if you assume the distance is a straight line. Otherwise you need to conform (add together or subtract) the missing length of the hill from your height. — Nov 23, 2017 at 13:08
@danielpopa Im not saying this is incorrect. Im saying this might non be accurate enough to utilise. — Dec xi, 2017 at 8:34
This solution wont work for object outside ground. For example a hanging light (without knowing the lights altitude) — May 10 at 8:31

Accepted Answer · 2011-01-03 21:42:22Z

Well yous should read how ithinkdiff.com "measures" the distance:

Uses the angle of the iPhone to gauge the distance to a signal on the ground. Agree the iPhone in forepart of you, align the point in the camera and get a directly reading of the distance. The altitude tin then be used in the speed tool.

Then basically information technology takes the height of where you agree the phone (eye-level), and so you lot must point the camera to the signal where object touches the footing. Then the phone measures the inclination and with uncomplicated trigonometry it calculates distance.

This is of course not very accurate. It gets less accurate the farther the object is. Also it assumes that the ground is level.

It IS possible then. Not accurate merely possible :)

Jan three, 2011 at 21:57

Answer 3 · 2011-01-03 21:24:11Z

Nope. The camera can but requite you image information and an paradigm alone doesn't requite you lot enough data to give you depth data. If you lot had multiple images that you had location data for or fifty-fifty video y'all could then process information technology to triangulate the distance, but a single image alone would not exist enough to give you a distance.

answered January 3, 2011 at 21:24

Daniel DiPaoloDaniel DiPaolo

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six

But with videocamera it is? I want to develop application like this on iPhone ithinkdiff.com/…

Jan three, 2011 at 21:29
Well, it'southward not quite equally simple equally "push, get altitude", just information technology would be more likely to be possible. But it'd still require y'all to accept information about the location at various points throughout the video. If you took video of a wall with a i human foot solid white circle painted on information technology, starting at 10 feet away and closing to 5 feet, you lot could use image processing/geometry to figure out how far away that circle was. For your purposes the general answer is "no".

Jan 3, 2011 at 21:31
I added link to video what I want to achieve. If it's possible with iPhone, I think it'south possible with Android. But I need a start, where to brainstorm with.

Jan 3, 2011 at 21:33
Y'all'll note that in the very clarification of that product that they crave you to put in the distance to the object being measured. "Uses the camera to find and analyze motion: Set the altitude to the object you desire to measure ..."

Jan 3, 2011 at 21:35
@Daniel Simply in video they measure the distance.

Jan 3, 2011 at 21:41

Answer 4 · 2016-12-11 20:29:08Z

answered Dec 11, 2016 at twenty:29

ChaseChase 21 one bronze badge · Answer 5 · 2011-12-12 05:22:50Z

You lot have the angle in the telephone'southward accelerometer. If y'all calculate the tangent of this angle and multiply information technology by the height of the camera lens, you get the altitude.

Peter O.

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answered Dec 12, 2011 at 5:22

ChaseChase

21 one bronze badge

intAintA 497 ii gold badges x silverish badges 23 statuary badges · Answer 6 · 2011-12-27 11:49:24Z

I think this App uses the arroyo MisterSquonk mentioned (its free). Lookout the "Trigonometry" technique.

answered December 27, 2011 at xi:49

intAintA

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Answer 7 · 2012-11-21 05:27:07Z

I call back by using FastCV you tin calculate the distance betwixt Camera and the object. In this You dont need to know the angle or the Position of photographic camera that you are belongings above ground Level. take a look at this question here

Answer 8 · 2016-04-25 01:53:37Z

One fashion to achieve this is using the DPI's in your device. Y'all can accept a picture and summate the tiptop. Simply you'll demand another object every bit a reference then yous volition be able to know the problem with this method could be the perspective betwixt the objects

strategaDstrategaD 251 2 silver badges 10 bronze badges · Answer 9 · 2018-05-24 15:28:37Z

I think it could be possible doing that using the phone camera. I know that the modern phones use lenses to focus on a object. If it is possible to know their focal length and their position(displacement) to focus on the chosen object it's also possible to determinate the distance.