How can i save the [x,y,intensity] of image if i am running a threshold intensity scan of a picture?

clc
source= imread('testimg.jpg');
[rows,coloumn,channels]=size(source)
% Scanning row & coloumn wise
a=1;
while a>=1 && a<=rows
    [b]=1;
    if b>=1 && b<=coloumn
        if source(a,b,3)>=100
            % Need help in saving this to specific coloumn in form a vector!
            xlswrite("data_oel.xlsx",b,'data','(B2:B169)') 
        end
        b=b+1;
    end
    xlswrite("data_oel.xlsx",a,'data','(A2:A300)')
    a=a+1;
end

Answer 1

[Image Analyst]

See attached demo where I write R, G, B, x, y to a CSV file. Is that what you want?

[Fawad Ali]

how can i figure out the high intensities of R,G,B if i read a matrix out of it

[Image Analyst]

You can use the max function

rgbImage = imread('peppers.png');
[r, g, b] = imsplit(rgbImage);
maxR = max(r(:))

maxR = uint8 255

maxG = max(g(:))

maxG = uint8 255

maxB = max(b(:))

maxB = uint8 255