003——矩阵的掩膜操作

原文链接：OpenCV--矩阵的掩膜操作

参考链接：OpenCV探索之路（十三）：详解掩膜mask

我的实验代码

法1

#include<opencv2/opencv.hpp>
#include<iostream>
#include<math.h>

using namespace cv;
int main(int argc, char **argv)
{
    Mat src, dst;
    src = imread("./girl.jpg");
    if (!src.data)
    {
        std::cout << "Could not load image...
" << std::endl;
        return -1;
    }
    namedWindow("Girl", CV_WINDOW_AUTOSIZE);
    imshow("Girl",src);

    int cols = src.cols*src.channels();
    int offsetx = src.channels();
    int rows = src.rows;
    dst = Mat::zeros(src.size(), src.type());
    double t = getTickCount();
    for (int row=1; row < rows - 1; row++)
    {
        const uchar* current = src.ptr<uchar>(row);
        const uchar* previous = src.ptr<uchar>(row - 1);
        const uchar* nest = src.ptr<uchar>(row + 1);
        uchar* output = dst.ptr<uchar>(row);
        for (int col = offsetx; col < cols; col++)
        {
            output[col] = saturate_cast<uchar>(5 * current[col] - (current[col - offsetx] + current[col + offsetx] + previous[col] + nest[col]));
        }
    }
    double timeconsume = (getTickCount() - t) / getTickFrequency();

    std::cout << "耗时：" << timeconsume << std::endl;
    namedWindow("Girl After", CV_WINDOW_AUTOSIZE);
    imshow("Girl After", dst);
    waitKey(0);
    return 0;
}

法2

#include<opencv2/opencv.hpp>
#include<iostream>
#include<math.h>

using namespace cv;
int main(int argc, char **argv)
{
    Mat src, dst;
    src = imread("./girl.jpg");
    if (!src.data)
    {
        std::cout << "Could not load image...
" << std::endl;
        return -1;
    }
    namedWindow("Girl", CV_WINDOW_AUTOSIZE);
    imshow("Girl",src);

    int cols = src.cols*src.channels();
    int offsetx = src.channels();
    int rows = src.rows;
    dst = Mat::zeros(src.size(), src.type());

    double t = getTickCount();
    Mat kernel = (Mat_<char>(3, 3) << 0, -1, 0, -1, 5, -1, 0, -1, 0);
    filter2D(src, dst, src.depth(), kernel);
    double timeconsume = (getTickCount() - t) / getTickFrequency();

    std::cout << "耗时：" << timeconsume << std::endl;
    namedWindow("Girl After", CV_WINDOW_AUTOSIZE);
    imshow("Girl After", dst);
    waitKey(0);
    return 0;
}