Edge Detection on figure with changed axes

Hi all,

I am performing edge detection on a mp4 file and displaying two figures.

One is displaying the original mp4 file with axes x = [0 720] | y = [0 720]; the other is displaying a specific portion of the original axes; lets say x=[300 400] | y = [350 450].

Right now, edge detection is being performed on the large frames and I am essentially zooming in to display what I want.

For the sake of computation power, I want to only perform edge detection only on the figure with the scaled axes instead of the larger mp4 file.

I am familiar with defining multiple figures, their titles, positions, etc. But I am unfamiliar with using imshow() on a specific figure. Can anyone tell me how to perform edge detection of a figure with scaled axes and display said figure?

Please let me know!

Also, if anyone has suggestions or input, I would appreciate them!