How to obtain sum of RGB color values of a pixel?

How to obtain sum of RGB color values of a pixel?

Without using I(:,:,1) ,I(:,:,2),I(:,:,3).

[Stephen23]

It is important to note that the sum of the R, G, and B values is not the same as the grayscale! This is because each of the R, G, and B values contribute unequally to the luminance, so they cannot be simply summed to get the grayscale equivalent of a color pixel. If you want the grayscale value, then the easiest way is to use rgb2gray.

Answer 1

[Titus Edelhofer]

Hi,

something like

sum(I, 3)

?

Titus

[Anushka]

Sir it didnt worked properly

[Titus Edelhofer]

Hi,

what do you mean b "not properly". Was there an error? Result not as expected (see comment by Stephen on grayscale)?

Titus

[John D'Errico]

Probably the image is uint8, so summing the pixels will overflow. Better might be

sum(double(I),3)