the relation between the distance and the number of pixels in the image

Hi guys I am trying to find the relationship between the number of pixels and the distance . I have taken some images for a pole at different distances, and I am trying to count the number of pixels for the width of this object in each image. could you please help me to do this in MATLAB. I am working with color images.

Answer 1

[Walter Roberson]

When the pole is N times further away, it will appear to be 1/N times as long, provided that the lens is linear (e.g., is not something like a fish-eye lens that distorts distance non-linearly with distance from the optical axes.)