改进的matlab极值中值滤波程序

以下是改进的Matlab极值中值滤波程序：

function y = medfilt2_extremes(x, w, p)

% x: input image
% w: window size, should be odd
% p: percentage of pixels to be replaced by median or max/min values

if nargin < 3
    p = 0.1;
end

if mod(w, 2) == 0
    error('Window size should be odd.');
end

[xh, xw] = size(x);
y = zeros(xh, xw);

% pad the image with zeros
pad_width = (w - 1) / 2;
x = padarray(x, [pad_width, pad_width], 'symmetric');

for i = 1:xh
    for j = 1:xw
        % get the window
        window = x(i:i+w-1, j:j+w-1);
        % sort the window values
        window_sorted = sort(window(:));
        % get the median value and the max/min values
        mid = window_sorted((w*w+1)/2);
        max_val = window_sorted(w*w - floor(w*w*p/2));
        min_val = window_sorted(floor(w*w*p/2)+1);
        % replace the pixel with the median value if it's an extreme value
        if x(i,j) == max(window(:)) || x(i,j) == min(window(:))
            y(i,j) = mid;
        else
            y(i,j) = x(i,j);
        end
        % replace a percentage of pixels with max/min values
        if rand < p
            if x(i,j) < min_val || x(i,j) > max_val
                y(i,j) = min_val + (max_val - min_val) * rand;
            end
        end
    end
end

y = uint8(y);

这个程序可以进行中值和极值滤波，并且可以选择替换一定比例的像素值为极值。其中，输入参数`x`是要进行滤波的图像，`w`是窗口大小，`p`是替换像素的比例，默认值为0.1。输出参数`y`是滤波后的图像。