arithmatic functions for gray scale image

i have a gray scale image.my codes are

V=(-1*diff(summ));%%gives the horizontal edges of the image

H=(-1*(diff(summ'))');%%gives the vertical edges of the image 

HV=imadd(H,V);%%i want to see the both edges in same image.
i'm very new for matlab.i dont know these codes are correct or not.is there any operation to convert the arithmatic results into image.thanks.

[Jan]

Now it would be helpful, if you explain what "summ" is. The more details we have to guess, the less matching the answers will be.

[mahesh chathuranga]

summ is the the image of cooccurrence matrix features(contrast and energy)

[Image Analyst]

The cooccurrence matrix is a 2D array and can be displayed as an image, true. But, the edges of the cooccurrence matrix??? I have no idea what that would even represent. I don't think it means anything, at least nothing intuitive that I can think of.

Answer 1

[Image Analyst]

Why not use imgradient() or imgradientxy()?

[mahesh chathuranga]

it gives the error message??? Undefined function or method 'imgradient' for input arguments of type 'double'.

[Image Analyst]

You must be using an old version of MATLAB. Please download the latest version. It's included in your maintenance contract.