Algorithm for measuring the Euclidean distance between pixels in an image?

Question

I have a number of images where I know the focal length, pixel count, dimensions and position (from GPS). They are all in a high oblique manner, taken on the ground with commercially available cameras. ![alt text][1] What would be the best method for calculating the euclidean distances between certain pixels within an image? If it is indeed possible. [1]: http://desmond.yfrog.com/Himg411/scaled.php?tn=0&server=411&filename=mjbm.jpg&xsize=640&ysize=640 "Sample Photograph""

Answer 1

you can reference the following

https://stackoverflow.com/questions/36985718/euclidean-distance-between-images

but any computer might be texed on its performance.