OpenCV C++版圖像去霧技術對比

圖像去霧是一種重要的圖像增強技術，可以有效地提高圖像的清晰度和細節。在OpenCV中，有多種圖像去霧算法可以實現，比較常用的有Dark Channel Prior和Fast Visibility Restoration等算法。

下面我們將分別使用Dark Channel Prior和Fast Visibility Restoration算法對同一張含有霧的圖像進行處理，然后進行對比。

首先是Dark Channel Prior算法的實現代碼：

#include <opencv2/opencv.hpp>

using namespace cv;

Mat dehazeDarkChannelPrior(Mat& src, double w = 0.95, int r = 15) {
    Mat src_gray;
    cvtColor(src, src_gray, COLOR_BGR2GRAY);

    Mat dark_channel = Mat::zeros(src.size(), CV_8UC1);
    for (int i = 0; i < src.rows; ++i) {
        for (int j = 0; j < src.cols; ++j) {
            Vec3b pixel = src.at<Vec3b>(i, j);
            dark_channel.at<uchar>(i, j) = std::min({ pixel[0], pixel[1], pixel[2] });
        }
    }

    Mat dark_channel_blur;
    boxFilter(dark_channel, dark_channel_blur, CV_8UC1, Size(r, r));

    Mat A = Mat::zeros(src.size(), CV_8UC1);
    for (int i = 0; i < src.rows; ++i) {
        for (int j = 0; j < src.cols; ++j) {
            A.at<uchar>(i, j) = dark_channel_blur.at<uchar>(i, j);
        }
    }

    Mat transmission = Mat::zeros(src.size(), CV_64FC1);
    for (int i = 0; i < src.rows; ++i) {
        for (int j = 0; j < src.cols; ++j) {
            transmission.at<double>(i, j) = 1.0 - w * dark_channel.at<uchar>(i, j) / A.at<uchar>(i, j);
        }
    }

    Mat transmission_blur;
    boxFilter(transmission, transmission_blur, CV_64FC1, Size(r, r));

    Mat dehazed = Mat::zeros(src.size(), CV_8UC3);
    for (int i = 0; i < src.rows; ++i) {
        for (int j = 0; j < src.cols; ++j) {
            Vec3b pixel = src.at<Vec3b>(i, j);
            dehazed.at<Vec3b>(i, j) = pixel - (pixel - A.at<uchar>(i, j)) / transmission_blur.at<double>(i, j);
        }
    }

    return dehazed;
}

int main() {
    Mat src = imread("foggy_image.jpg");

    Mat dehazed = dehazeDarkChannelPrior(src);

    imshow("Original", src);
    imshow("Dehazed Dark Channel Prior", dehazed);
    waitKey();

    return 0;
}

然后是Fast Visibility Restoration算法的實現代碼：

#include <opencv2/opencv.hpp>

using namespace cv;

Mat dehazeFastVisibilityRestoration(Mat& src, double beta = 1.0, double omega = 0.95, int r = 60) {
    Mat src_gray;
    cvtColor(src, src_gray, COLOR_BGR2GRAY);

    Mat dark_channel = Mat::zeros(src.size(), CV_8UC1);
    for (int i = 0; i < src.rows; ++i) {
        for (int j = 0; j < src.cols; ++j) {
            Vec3b pixel = src.at<Vec3b>(i, j);
            dark_channel.at<uchar>(i, j) = std::min({ pixel[0], pixel[1], pixel[2] });
        }
    }

    Mat dark_channel_blur;
    boxFilter(dark_channel, dark_channel_blur, CV_8UC1, Size(r, r));

    Mat A = Mat::zeros(src.size(), CV_8UC1);
    for (int i = 0; i < src.rows; ++i) {
        for (int j = 0; j < src.cols; ++j) {
            A.at<uchar>(i, j) = dark_channel_blur.at<uchar>(i, j);
        }
    }

    Mat transmission = Mat::zeros(src.size(), CV_64FC1);
    for (int i = 0; i < src.rows; ++i) {