homofil2Wrapper(image, RGBVHS, d, n, rL, rH)

%
% Wrapper: Raul Correal
% ([e-mail])
% 
% MATLAB code that performs Homomorphic filtering, Using Butterworth
% High Pass Filter for performing filtering.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


function im_e = homofil2Wrapper(image, RGBVHS, d, n, rL, rH)

	if (ndims(image) > 2)

		% RGB image
		if (RGBVHS) == 1

			% Work in RGB space
            R = image(:,:,1);
            G = image(:,:,2);
            B = image(:,:,3);

            im_e(:,:,1) = homofil2(R, d, n, rL, rH);
            im_e(:,:,2) = homofil2(G, d, n, rL, rH);
            im_e(:,:,3) = homofil2(B, d, n, rL, rH);
            
            im_e = uint8(im_e);

		elseif (RGBVHS) == 2

			% Work in HSV space
			B = rgb2hsv(image);
			V = B(:,:,3);
			H = homofil2(V, d, n, rL, rH);
			B(:,:,3) = mat2gray(H);

            im_e = uint8((hsv2rgb(B)).*255);
		end

	else

		% Gray image
		im_e = homofil2(image, d, n, rL, rH);

	end


end

function im_e = homofil2(image, d, n, alphaL, aplhaH)

im = image;

if (ndims(image) > 2)
  im=rgb2gray(im);
end

im=double(im);

[r c]=size(im);

%%%%%%%%%% Butterworth high pass filter %%%%%%%%%%%%%%

A=zeros(r,c);
H=zeros(r,c);

for i=1:r
    for j=1:c
        A(i,j)=(((i-r/2).^2+(j-c/2).^2)).^(.5);
        H(i,j)=1/(1+((d/A(i,j))^(2*n)));
    end
end

%%%%%%%%%%%%%Using it for my application as homomorphic filtering is
%%%%%%%%%%%%%application specific, taking the value of alphaL and alphaH
%%%%%%%%%%%%%values accordingly.
%alphaL=.0999;
%aplhaH=1.01;
H=((aplhaH-alphaL).*H)+alphaL;
H=1-H;
%%%%%log of image
im_l=log2(1+im);
%%%%%DFT of logged image
im_f=fft2(im_l);
%%%%%Filter Applying DFT image
im_nf=H.*im_f;
%%%%Inverse DFT of filtered image
im_n=ifft2(im_nf);

im_a=abs(im_n);

%%%%%Inverse log 
im_e=exp(im_a);

%im_e = mat2gray(im_e);
%im_e = imadjust(im_e, [], [min(min(im)) max(max(im))]);


% subplot(1,2,2);
%subplot(122)
%imshow((im_e),[])

% figure
% imshow(H)

end