掩膜操作

#include <iostream>

#include <opencv2/opencv.hpp>
#include <opencv2/imgproc/types_c.h>
#include <opencv2/highgui.hpp>

using namespace cv;
using namespace std;

int main()
{
//读取图片并进行数据验证
Mat input = imread("E:/Image/yg.jpg");
if (!input.data || input.empty())
{
printf("load image has error!\n");
return 0;
}
namedWindow("input image", 1);
imshow("input image", input);

//手动掩膜操作
double t1 = getTickCount();//记录时间
Mat out1 = Mat::zeros(input.size(), input.type());//初始化图片
int chans = input.channels();//通道数
int cols = input.cols * chans;//列数*通道数
int rows = input.rows;//行数
for (int row = 1; row < rows - 1; row++)
{
const uchar* prev = input.ptr<uchar>(row - 1);//前一行指针
const uchar* current = input.ptr<uchar>(row);//当前行指针
const uchar* next = input.ptr<uchar>(row + 1);//下一行指针
uchar* out_row = out1.ptr<uchar>(row);//输出图片行

for (int col = chans; col < cols - chans; col++)
{
//saturate_cast:设置数据在某一范围内，uchar:[0,255];
out_row[col] = saturate_cast<uchar>(5 * current[col] - (prev[col] + next[col] + current[col - chans] + current[col + chans]));
}
}
double time1 = (getTickCount() - t1) / getTickFrequency();
printf("time1: %.4lf\n", time1);//输出double类型数据

namedWindow("out1 image", WINDOW_AUTOSIZE);
imshow("out1 image", out1);

//API掩膜操作
double t2 = getTickCount();
Mat out2 = Mat::zeros(input.size(), input.type());
Mat kernel = (Mat_<char>(3, 3) << 0, -1, 0, -1, 5, -1, 0, -1, 0); //该掩膜可增加图片对比度
filter2D(input, out2, input.depth(), kernel);
double time2 = (getTickCount() - t2) / getTickFrequency();
printf("time2: %.4f\n", time2);

namedWindow("out2 image", 1);
imshow("out2 image", out2);

waitKey(0);
return 0;

//std::cout << "Hello World!\n";
}