How to calculate a distance between two point in a cercle ?

i have a binary image of cercle and i would calculate a distance between two point

[Jan]

Please post more details, e.g. how the interesting pixels are defined.

Answer 1

[Image Analyst]

Is there any reason why the normal Pythagorean theorem to find the Euclidean distance won't work?

[safa]

I am a beginner user of matlab language I do not know how to translate the theorem of Pythagoras by this language

[Image Analyst]

The same way it looks in virtually every other language:

distance = sqrt((column1-column2)^2+(row1-row2)^2)

where (row1,column1) is the first point and (row2,column2) is your second point.