双边滤波总结 包括代码与注释.docVIP

双边滤波总结 包括代码与注释 双边滤波器： 图像滤波，记载尽量保留图像细节特征的条件下对目标图像的噪声进行抑制。 双边滤波是一种可以保边去噪的滤波器。它的原理是因为滤波器由两个函数构成，一个函数是有几何空间距离决定滤波器系数，另一个有像素差值决定滤波器系数。 function B = bfilter2(A,w,sigma) % Verify that the input image exists and is valid. if ~exist(#39;A#39;,#39;var#39;) || isempty(A) error(#39;Input image A is undefined or invalid.#39;); end if ~isfloat(A) || ~sum([1,3] == size(A,3)) || ... min(A(:)) lt; 0 || max(A(:)) gt; 1 error([#39;Input image A must be a double precision #39;,... #39;matrix of size NxMx1 or NxMx3 on the closed #39;,... #39;interval [0,1].#39;]); end % Verify bilateral filter window size. if ~exist(#39;w#39;,#39;var#39;) || isempty(w) || ... numel(w) ~= 1 || w lt; 1 w = 5; end w = ceil(w); % Verify bilateral filter standard deviations. if ~exist(#39;sigma#39;,#39;var#39;) || isempty(sigma) || ... numel(sigma) ~= 2 || sigma(1) lt;= 0 || sigma(2) lt;= 0 sigma = [3 0.1]; end % Apply either grayscale or color bilateral filtering. if size(A,3) == 1 B = bfltGray(A,w,sigma(1),sigma(2)); else B = bfltColor(A,w,sigma(1),sigma(2)); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Implements bilateral filtering for grayscale images. function B = bfltGray(A,w,sigma_d,sigma_r) % Pre-compute Gaussian distance weights. [X,Y] = meshgrid(-w:w,-w:w); G = exp(-(X.^2+Y.^2)/(2*sigma_d^2)); % Createwaitbar. h = waitbar(0,#39;Applying bilateral filter...#39;); set(h,#39;Name#39;,#39;Bilateral Filter Progress#39;); % Apply bilateral filter. dim = size(A); B = zeros(dim); for i = 1:dim(1) for j = 1:dim(2) % Extract local region. iMin = max(i-w,1); iMax = min(i+w,dim(1)); jMin = max(j-w,1); jMax = min(j+w,dim(2)); I = A(iMin:iMax,jMin:jMax); % Compute Gaussian intensity weights. H = exp(-(I-A(i,j)).^2/(2*sigma_r^2)); % Calculate bilateral filter response. F = H.*G