How to plot picese-wise linear transformation graph?

Ig = rgb2gray(imread('example.jpg'));

A = 50;

B = 180;

In = (A < Ig) & (Ig < B);

I want to plot "In" graph like this

So, on the x-axis there are values ​​from 0 to 255, and on the y-axis I want the values ​​between A and B to rise like a peak.

[Dyuman Joshi]

What's the relation of reading of the image to getting this graph/plot? The graph/plot can be obtained without the image data.

Answer 1

[檮杌]

Would this work for you?

X = rgb2gray(imread('peppers.png'));
idx = X > 50 & X < 180;
X_transformed = uint8(double(X).*idx);
montage({X, X_transformed});