I am not certain what you mean by ‘intensity’, but this is one possibility for you to experiment with:
Pprs3 = imread('peppers.png'); % Colour Image
Pprs1 = rgb2gray(Pprs3); % Grayscale Image
x = 0:size(Pprs1,2)-1;
y = 0:size(Pprs1,1)-1;
[X,Y] = meshgrid(x,y); % Coordinate Matrices (Not Necessary)
figure(1)
meshc(X, Y, Pprs1) % Mesh Plot
grid on
xlabel('X')
ylabel('Y')
zlabel('Intensity')
colormap(jet) % Set ‘colormap’
The code first reads the image as RGB (3D) matrix of uint8 values, then converts it to a grayscale matrix of uint8 values. It then creates appropriate coordinate matrices (not necessary, but the plots look better with them), and plots them using the meshc function and the jet colormap. You can also use surf (or surfc) and other colormaps.
Experiment with this code and your image to get the result you want.
