Need help on Image Gradient functions in matlab

I want to calculate the gradient direction of an image.

I would like to know the differences between gradient, imgradient, imgradientxy functions in matlab.

What's the difference between gradient direction and directional gradient?

Please help.

Thanks in Advance.

[.. Vamshi]

I tried hard but couldn't find much. Any help is appreciated.

Answer 1

[Image Analyst]

Did you look in the help? gradient is the slope of an image along a direction. imgradient returns the max gradient and the direction the max slope occurs along. Other functions may give you the vertical, horizontal, or average gradient - depends on the function.

[.. Vamshi]

yeah... I checked. gradient and imgradient also does the same. but could not understand the difference.

[Walter Roberson]

matthew molteno commented

This hasn't been fully answered. Does gradient give the same result as imgradientxy?

[Image Analyst]

gradient uses the Laplacian while imgradient uses Prewitt or Sobel filters to give the gradient.

imgradient gives magnitude and direction while imgradientxy give the derivative in strictly the x and y direction. Kind of like giving x and y instead of sqrt(x^2+y^2) and atan(y/x).