新手学习opencv四：Mat和IplImage简单处理图像耗时

清疚 2022-08-20 11:11 11阅读 0赞

#                           新手学习opencv四：Mat和IplImage简单处理图像耗时 #

处理目的：对一张读入的图像，进行灰度值反转，即255减去原始灰度值。

循环200次，取平均耗时。

#include "cv.h"
    #include "highgui.h"
    #include <iostream>
    using namespace cv;
    using namespace std;
    int main()
    {
    	string imageName ="1001.jpg";
    	Mat src = imread(imageName,1);
    	Mat res = Mat::zeros(src.rows,src.cols,src.type());
    
    	long int count = 0;
    	float num = 0;
    	double t1 = (double)getTickCount();
    	for(int n=0;n<200;n++)
    	{
    		for (int i = 0; i < src.rows; i++)
    		{
    			uchar* data= res.ptr<uchar>(i); // 每一行图像的指针
    			uchar* idata= src.ptr<uchar>(i); // 每一行图像的指针
    			for (int j = 0; j < src.cols*src.channels(); j++)
    			{
    				*data++=255-(*idata++);  
    			}
    		}
    	}
    	t1= ((double)getTickCount() - t1)/getTickFrequency()/200;
    	imshow("src",src);
    	imshow("result1",res);
    	///
    	int nl= src.rows; 
    	int nc= src.cols * src.channels(); 
    	if (src.isContinuous()&&res.isContinuous())  
    	{
    		nc= nc*nl; 
    		nl= 1;  
    	}
    	double t2 = (double)getTickCount();
    	for(int n=0;n<200;n++)
    	{
    		for (int i=0; i<nl; i++)
    		{
    			uchar* data= res.ptr<uchar>(i); 
    			uchar* idata= src.ptr<uchar>(i);
    			for (int j=0; j<nc; j++)
    			{
    				*data++=255-(*idata++);  
    			}    
    		}
    	}
    	t2= ((double)getTickCount() - t2)/getTickFrequency()/200; 
    	imshow("src2",src);
    	imshow("result2",res);
    	//IplImage类遍历//
    	IplImage * img = cvLoadImage("1001.jpg");
    	IplImage *res2=cvCreateImage(cvGetSize(img),IPL_DEPTH_8U,img->nChannels);
    	char  *data = img->imageData;
    	int step = img->widthStep;
    	int chanel = img->nChannels;
    	char  *outdata = res2->imageData;
    	double t3= (double)getTickCount();
    	for(int n=0;n<200;n++)
    	{
    		for(int i=0;i<img->height;i++)
    		{
    			for(int j=0;j<img->width;j++)
    			{
    				outdata[i*step + j*chanel] = 255-data[i*step + j*chanel];
    				outdata[i*step + j*chanel+1] = 255-data[i*step + j*chanel + 1];
    				outdata[i*step + j*chanel+2] = 255-data[i*step + j*chanel + 2];
    			}
    		}
    	}
    	t3= ((double)getTickCount() - t3)/getTickFrequency()/200; 
    	cvNamedWindow("yaunshi");
    	cvShowImage("yaunshi",img);
    	cvNamedWindow("result3");
    	cvShowImage("result3",res2);
    	cout <<"Mat类简单处理耗时1：" << t1 << endl;
    	cout <<"Mat类简单处理耗时2：" << t2 << endl;
    	cout <<"IplImage类简单处理耗时："<<t3<< endl;
    	cvWaitKey(0);
    	cvReleaseImage(&img);
    	cvReleaseImage(&res2);
    	cvDestroyWindow("yaunshi");
    	cvDestroyWindow("result3");
    	return 0;
    }

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