opencv学习笔记（05）——操作相邻区域

下面的例子以灰度图像为例：

#include <opencv2highguihighgui.hpp>
#include <opencv2imgprocimgproc.hpp>
#include <opencv2corecore.hpp>


using namespace cv;

void sharpen(const cv::Mat& img_original, cv::Mat& img_altered);    

void sharpen2D(const cv::Mat& img_original, cv::Mat& img_altered);    

int main()
{

    cv::Mat img_original = cv::imread("F:\images\boldt.jpg", cv::IMREAD_GRAYSCALE );     
    cv::Mat img_altered = img_original.clone();

    // 锐化
    sharpen2D(img_original, img_altered);        

    cv::namedWindow("orignal");
    cv::imshow("orignal", img_original);
    cv::namedWindow("altered");
    cv::imshow("altered", img_altered);

    cv::waitKey();

    return 0;
}

void sharpen(const cv::Mat& img_original, cv::Mat& img_altered)    
{

    int nc = img_original.cols;
    int nl = img_original.rows;
    
    for(int j=1; j<nl-1; j++)
    {
        const uchar* previous = img_original.ptr<const uchar>(j-1); 
        const uchar* current = img_original.ptr<const uchar>(j); 
        const uchar* next = img_original.ptr<const uchar>(j+1); 

        uchar*     output = img_altered.ptr<uchar>(j);    

        for(int i=1; i<nc-1; i++)
        {
            *output++ = saturate_cast<uchar>( 5 * current[i] - previous[i] - next[i] - current[i-1] - current[i+1] );    
        }
    }

    img_altered.row(0).setTo(cv::Scalar(0));
    img_altered.row(nl-1).setTo(cv::Scalar(0));
    img_altered.col(0).setTo(cv::Scalar(0));
    img_altered.col(nc-1).setTo(cv::Scalar(0));

}


void sharpen2D(const cv::Mat& img_original, cv::Mat& img_altered)
{
    Mat kernel(3, 3, CV_32F, cv::Scalar(0));
    kernel.at<float>(0,1) = - 1.0;
    kernel.at<float>(1,0) = - 1.0;
    kernel.at<float>(1,2) = - 1.0;
    kernel.at<float>(2,1) = - 1.0;
    kernel.at<float>(1,1) = 5.0;

    //Mat_<cv::Scalar> kernel2 = kernel;
    //kernel2(0,1) = -1.0;
    //kernel2(1,0) = -1.0;
    //kernel2(1,2) = -1.0;
    //kernel2(2,1) = -1.0;
    //kernel2(1,1) = 5.0;

    cv::filter2D(img_original, img_altered, img_original.depth(), kernel);    

}

下面是彩色图像的例子：