compare the intensity of a pixel with the one next to it

I have an Image (grayscale) and i want to compare each Pixel with the one next to it and if the value increases or decreases with more than 300 , i want to store its Location and then plot it with another Color on the picture . can any one help me please ? Thank you

Answer 1

[Takuji Fukumoto]

if 'one next to it' means right side pixcel, you can identify the value increase/decrease more than 300.

I = imread('filename');
r = numel(I(:,1))
ext = zeros(r,1);
I1 = [I ext];
I2 = [ext I];
I3 = I1-I2;
Iout = abs(I3) > 300;

[Walter Roberson]

Better is I3 = double(I1) - double(I2); because images are typically integer data class.

[Yassine Zaafouri]

my image is already double but thank you for this anyway