I'm looking for a software that could assist me in defining geometric shapes over an existing image, define a scale, and display the length and areas of various elements.
For example, let's say I have this picture:
This is a contrived example, because the scale is already known in this specific case, and I would certainly use a GIS for this, but this serves just as an illustration.
I would like to be able to define the scale using the known dimension of a tennis court, then define a polygon over the pool, then compute its area.