opencv学习笔记（02）——遍历图像（指针法）

#include <opencv2\core\core.hpp>
#include <opencv2\highgui\highgui.hpp>
#include <opencv2\imgproc\imgproc.hpp>
#include <iostream>
 
void colorReduce(cv::Mat& image, int div=)
{
    int nr = image.rows;
    int nc = image.cols * image.channels();
 
    int n = static_cast<int>( cv::log(static_cast<double>(div)) / cv::log(2.0) );
    uchar mask = 0xFF << n;
 
    for(int i=; i<nr; i++)
    {
        uchar* data = image.ptr<uchar>(i);
        for(int j=; j<nc; j++)
        {
            //*data++ = *data - *data % div + div / 2;
            *data++ = (*data & mask) + div / ;
        }
    }
 
}
 
int main(int argc, char** argv)
{
 
    cv::Mat img = cv::imread("F:\\images\\boldt.jpg");
    cv::Mat img2 = img.clone();    
 
    double duration;
    duration = static_cast<double>(cv::getTickCount());
 
    colorReduce(img2);
    duration = static_cast<double>(cv::getTickCount()) - duration;
    duration /= cv::getTickFrequency();
 
    cv::namedWindow("original");
    cv::imshow("original", img);
    cv::namedWindow("altered");
    cv::imshow("altered", img2);
 
    std::cout << duration << std::endl;
 
    cv::waitKey();
    return ;
 
}