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 <opencv2\highgui\highgui.hpp>

#include <opencv2\imgproc\imgproc.hpp>

#include <opencv2\core\core.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：