Measuring distance between two points in an image

Hello, I'm working on a MATLAB project at uni and i've been trying to find out how to measure sizes of objects in a given image. For example - Measuring the size of a foot through image proccessing. If you have any knowledge about these kind of analasys, I would be more than happy if you could share it.

[Adam]

What are you actually asking here? What is in the question title or the much wider question in the body which seems to be asking how to do image processing and identify objects before you get anywhere near measuring them?

Answer 1

[Matt J]

imdistline() will probably help.

Answer 2

[Sean]

Check this out:

http://www.ipinlaser.com/content.php?id=4795

Answer 3

[Image Analyst]

See my attached spatial calibration demo.

[AVINASH SURESHRAO DIKKAR 17MMT1022]

i refered your spatial calibration demo code. I'm doing a matlab project for the inspection of chain link for that I have to find out the object position and measurement. While going through your code I didnt understand how you created a boundary around the object and created a line into that. Can you please explain to me and can you explain me the formula for distance which you use in your code. Please explain me code it is very helpfull to me and my project.

[Image Analyst]

You can try imfreehand(). I attach demos.

Or you can use roipoly() or roipolyold().

Here is an explanation for how distance is calculated: Wikipedia on Pythagorean Theorem