function I = gaussianBlur(image,sigma)

     k = gaussianKernel(sigma);

     blurSize = floor(length(k)/2);
     imageSize=  size(image);

%deal with the stupid boundary condition

%duplicate top and bottom edges
image = cat (1, repmat(image(1,:),[blurSize,1]),...
                  image,... 
		  repmat(image(imageSize(1),:),[blurSize,1]));
%duplicate left and right edges
image = cat (2, repmat(image(:,1),[1,blurSize]),...
                  image,...
                  repmat(image(:,imageSize(2)),[1,blurSize]));
									
     
     
     I = conv2(conv2(image,k,'valid'),k','valid');
     %size(I); imagesc(I); axis image;