filter_gaussian.m
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上传日期:2018-05-10
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- %/////////////////////////////////////////////////////////////////////////////////////////////
- % Author : Scott Ettinger
- %
- % filter_gaussian(img, order, sig)
- %
- % The image is first padded with the outer image data enough times to allow for the size of the
- % filter used.
- function image_out = filter_gaussian(img,order,sig)
- img2 = img;
- for i=1:floor(order/2) %pad image borders with enough for filter order
-
- [h,w] = size(img2);
-
- img2 = [img2(1,1) img2(1,:) img2(1,w);
- img2(:,1) img2 img2(:,w);
- img2(h,1) img2(h,:) img2(h,w)];
- end
-
- f = gauss1d(order,sig); %create filter coefficient matrix
-
- image_out = conv2(img2,f,'valid'); % do the filtering
- image_out = conv2(image_out,f','valid'); % do the filtering
- %/////////////////////////////////////////////////////////////////////////////////////////
- function f = gauss1d(order,sig)
- f=0;
- i=0;
- j=0;
- %generate gaussian coefficients
- for x = -fix(order/2):1:fix(order/2)
- i = i + 1;
- f(i) = 1/2/pi*exp(-((x^2)/(2*sig^2)));
- end
- f = f / sum(sum(f)); %normalize filter
- %/////////////////////////////////////////////////////////////////////////////////////////
- function f = gauss2d(order,sig)
- f=0;
- i=0;
- j=0;
- %generate gaussian coefficients
- for x = -fix(order/2):1:fix(order/2)
- j=j+1;
- i=0;
- for y = -fix(order/2):1:fix(order/2)
- i=i+1;
- f(i,j) = 1/2/pi*exp(-((x^2+y^2)/(2*sig^2)));
- end
- end
- f = f / sum(sum(f)); %normalize filter