How to get the first derivative of pixels along of line?

#Here's my code

#it works for one frame when I did 'plot(diff(test))' but I need a way to implement it to the whole images

imshow(M(:,:,1))
[x ,y]= ginput(2);

dif = zeros(size(M,3),1);

for i = 1:size(M,3)
    I = M(:,:,i);
    
    n = ceil(norm([diff(x), diff(y)]));
    
    test = improfile(I,linspace(x(1), x(2),n), linspace(y(1), y(2),n));
end

dif(i) = diff(test);

[Rik]

Are you using this code because you want the derivative in an arbitrary direction?

Also, this code overwrites the test variable each iteration, so only the blue channel is stored.

[BA]

@RikI amtrying to capture pixel differences between to two point using line of rio(see attached pic)

[Rik]

I don't understand what mean. If the solution from KSSV doesn't work for you, you will have to explain what you mean by that.

[Rik]

Why did you flag your question as unclear? The only person who can clarify your question is you. Why don't you do so?

And why did you change your user name?

[BA]

@RikI'd like to do some attempts and then reframe the question.

Answer 1

[KSSV]

REad about gradient