Need a code for quaternion fractional differential technique using for color image

Hi Everyone,

I need a matlab code for color image edge detection using quaternion
fractional differential.Its for ma final year project in image processing.
I did some code for above title ,but it's not giving a proper output,please verify that also,

g=imread('cameraman.tif');
f=g);

y=fderiv(1,f,1);

in function

% This function calculates the fractional derivative of order �d� for the
% given function r(t). It is assumed that the vector �r� contains the
% samples of the continuous signal r(t) which we are going to calculate its
% fractional derivative. �h� is a constant and represents the sampling
% period of r(t) (the time period between two samples). �h� must be small
% enough in the sense of Nyquist sampling theorem.
% �y� is the result achieved by applying the fractional differentiation
% operator on the input �r�. This contains the samples of the real output
% y(t) with the same sampling period used for �r�.
% It makes use of the Gr�nwald-Letnikov definition. The first element of
% the vector "r", i.e. r(1), is always zero.
%
% d : the order of fractional differentiation
% r : samples of the signal to be differentiated
% h : sampling poriod


function [y] = fderiv(d,r,h)

temp = 0;
for i=1:length(r)
for j=0:i-1
%
temp = temp+(-1)^j*(gamma(d+1)/(gamma(j+1)*gamma(d-j+1)))*r(i-j);
end
y(i) = temp;
temp = 0;
end
y = y/(h^d);




please help me !

Thanks in advance!!