how to acess decimal values of grayscale image?

i got figure of grayscale images. i found from the figure that RGB values of all pixels are in decimals.When i tried to access these decimal values, it is showing R value as 3 digit number,not decimal.How to acess decimal value?

[darova]

Try to divide by 255. Color can be stored or (0..1) or (0 .. 255)

[aswathy pavithran]

it is not giving exact value sir. thank you for the reply

Answer 1

[aswathy pavithran]

In gray scale image it is returning index value not the intensity.To get intensity value use code mat2gray();