暗通道先验去雾算法matlab代码

以下是一个简单的基于 MATLAB 的暗通道先验去雾算法的实现代码：

% 读取原始图像
img = imread('foggy_image.jpg');
figure, imshow(img), title('Original Image');

% 转换为灰度图像
gray_img = rgb2gray(img);

% 计算暗通道值
patch_size = 15;
dark_channel = calc_dark_channel(gray_img, patch_size);

% 估算全局大气光值
atmospheric_light = estimate_atmospheric_light(img, dark_channel);

% 估算场景透射率
transmission = estimate_transmission(gray_img, atmospheric_light, dark_channel);

% 去雾处理
dehazed_img = dehaze(img, transmission, atmospheric_light);

figure, imshow(dehazed_img), title('Dehazed Image');

% 计算暗通道值
function dark_channel = calc_dark_channel(img, patch_size)
    % 对图像进行补边，以避免邻域边界问题
    img = padarray(img, [patch_size, patch_size], 'symmetric');
    % 计算每个像素的暗通道值
    dark_channel = min(im2col(img, [patch_size, patch_size], 'sliding'), [], 1);
    % 将结果重塑为原始图像大小
    dark_channel = reshape(dark_channel, size(img) - [patch_size, patch_size] + 1);
end

% 估算全局大气光值
function atmospheric_light = estimate_atmospheric_light(img, dark_channel)
    [rows, cols] = size(dark_channel);
    num_pixels = rows * cols;
    num_samples = floor(num_pixels * 0.001);
    [~, indices] = sort(dark_channel(:), 'descend');
    top_indices = indices(1:num_samples);
    atmospheric_light = max(max(img(top_indices)));
end

% 估算场景透射率
function transmission = estimate_transmission(gray_img, atmospheric_light, dark_channel)
    % 估算场景透射率
    transmission = 1 - 0.95 * (dark_channel ./ atmospheric_light);
    % 使用全局大气光值对结果进行归一化
    transmission = transmission ./ max(transmission(:));
    % 避免出现除零错误
    transmission(transmission < 0.1) = 0.1;
end

% 去雾处理
function dehazed_img = dehaze(img, transmission, atmospheric_light)
    % 转换为浮点数类型
    img = im2double(img);
    % 对每个通道进行去雾处理
    for i = 1:3
        channel = img(:, :, i);
        channel_transmission = repmat(transmission, [1, 1, 3]);
        channel_atmospheric_light = repmat(atmospheric_light, [size(img, 1), size(img, 2), 1]);
        dehazed_channel = (channel - channel_atmospheric_light) ./ channel_transmission + channel_atmospheric_light;
        % 将像素值限制在 0 到 1 之间
        dehazed_channel(dehazed_channel < 0) = 0;
        dehazed_channel(dehazed_channel > 1) = 1;
        dehazed_img(:, :, i) = dehazed_channel;
    end
end

这段代码实现了暗通道先验去雾算法的基本步骤，可以对输入图像进行去雾处理。需要注意的是，该代码仅供参考，实际应用中可能需要进行更多的调整和优化。