@wp, thanks. I suppose that's the math part, but I would also like to know how it would be done programatically with this imaging library.

Let´s say I have an image of an insect and beside the insect I have also an object of know size (a dime , let´s say). So I know the size of the dime, from that size how would I go about calculating the size of the insect. Of course, I´m not looking for exact precision, but a close enough measurement would be good.

I hope that explains somewhat what I´m trying to achieve.

Thanks

Does anyone know how to use this library to get the measurements of an object in an image with a reference scale in the image? For example, I have an object known to be 5 cm wide, so another object's width beside it can be deduced.

Thanks
Javier