I want a code that I can measure the picture of object , and the matlab code tell me the real length of each object , who knows ?

for example , I can measure the length of car in the picture , and mat lab tell me how much cm the length of real car

anyone can help me ????????????????????

Answer 1

[Walter Roberson]

This cannot be done. You need to know at least one real-world distance in the picture.

An object in a picture that is 837 pixels wide might be 837 mm wide and 1 meter away, or it might be 837 cm wide and 10 meter away, or it might be 837 m wide and 1 km away. There is no way to tell without a physical distance.

If you need to go out with a piece of string and a measuring tape and measure the width of the lane, or the height of a stop sign, then do that.

If it helps, the last time I measured a stop sign, it was 2m 14cm from the top of the sign to the ground.

[sara]

do u have codes ? that helps me "?

[Image Analyst]

sara, I gave you code in http://www.mathworks.com/matlabcentral/answers/111945#answer_120468. And we went all over this calibration stuff in that thread, before you started this duplicate one. Apparently "codes" do not help u. But I'm not sure you even have an image. It looks like you have some kind of laser scanner system.