Perhaps my mind isn't mathematically competent enough to do this, but here it goes:
I am using Photoshop. I have 2 images taken from different heights. Both images have the same object in it (so the size of this object remains the same) but I am trying to resize both images so that this object is the same pixel size. That way I can properly measure the difference between other objects in the images with the proper ratio.
My end goal is to measure the differences of scars healing (before and after) using a same-size object in both images as a baseline.
To measure the difference in the photo, I have been counting pixels using the histogram feature:
Even though i changed the pixel width and height to roughly the same size, the 2 images have a drastically different number of pixels. So comparing the red or white from the before to the after won't make sense until I can get these to match.
Can anyone point me in the right direction here? How can I compare apples to apples here?
