Image - calculating gradient

Hi all, I have a grayscale image. I need to calculate the gradient from where it's saturated to where it's fading out. Does matlab has a function for that? If not, do you have any ideas on how to do so?

thanks.

Answer 1

[Image Analyst]

Did you look? If you had, you would have seen gradient(). You can also use conv2() or edge() or others. Post your image if you want more help.

[Nima Azar]

So this image is very similar to what I'm dealing with:

http://www.buildtutorial.com/wp-content/uploads/2010/04/02-light-gradient.jpg

I need to select the area first then calculate the gradient on the image. Sorry I'm very new to matlab.

regards,

[Image Analyst]

And how do you want to select an area (before calculating the gradient)? Automatically based on intensity or something? Manually by having user trace some area?