OPENCV 3. 图像的加载、保存与显示

a. 加载图像

CVAPI(IplImage*) cvLoadImage( const char* filename, int iscolor CV_DEFAULT(CV_LOAD_IMAGE_COLOR));

第2个参数为加载图像的方式，如灰度图像，原图等；

//enum//{///* 8bit, color or not *///    CV_LOAD_IMAGE_UNCHANGED  =-1,///* 8bit, gray *///    CV_LOAD_IMAGE_GRAYSCALE  =0,///* ?, color *///    CV_LOAD_IMAGE_COLOR      =1,///* any depth, ? *///    CV_LOAD_IMAGE_ANYDEPTH   =2,///* ?, any color *///    CV_LOAD_IMAGE_ANYCOLOR   =4//};

如果想以图像最原始的状态进行加载，则可设该值为：

CV_LOAD_IMAGE_ANYDEPTH|CV_LOAD_IMAGE_ANYCOLOR

b.保存文件

/* save image to file */CVAPI(int) cvSaveImage( const char* filename, const CvArr* image,                        const int* params CV_DEFAULT(0) );

c.显示图像

/* create window */CVAPI(int) cvNamedWindow( const char* name, int flags CV_DEFAULT(CV_WINDOW_AUTOSIZE) );

name:窗口的标志，如果已经有同名窗口，则该函数什么也不干。

/* display image within window (highgui windows remember their content) */CVAPI(void) cvShowImage( const char* name, const CvArr* image );

/* wait for key event infinitely (delay<=0) or for "delay" milliseconds */CVAPI(int) cvWaitKey(int delay CV_DEFAULT(0));

显示一幅图像时，需要等待一定的时间，否则窗口会一闪而过而来不及看清；

下面的例子加载一副图像，并在指定位置插入一幅LOGO的图像：

#include<iostream>  #include <opencv2/core/core.hpp>  #include <opencv2/highgui/highgui.hpp>  using namespace cv;  int main()  {     // 加载两幅图像    IplImage * pData = cvLoadImage("D:\\Image\\Desert.jpg", CV_LOAD_IMAGE_COLOR);    IplImage * pLogo = cvLoadImage("D:\\Image\\Penguins.jpg", CV_LOAD_IMAGE_COLOR);    //显示这两幅图像    cvNamedWindow("Desert",CV_WINDOW_AUTOSIZE );    cvShowImage("Desert", pData);    cvNamedWindow("pLogo",CV_WINDOW_AUTOSIZE );    cvShowImage("pLogo", pData);    // 设置ROI区域，进行拷贝和还原ROI区域    cvSetImageROI(pData, cvRect(10, 10, pLogo->width, pLogo->height));    cvCopy(pLogo, pData);    cvResetImageROI(pData);      // 保存图像    int p[3] = {CV_IMWRITE_JPEG_QUALITY, 100, 0};     cvSaveImage("D:\\Image\\Desert-Penguins.jpg", pData, p);    // 显示图像    cvNamedWindow("desert",CV_WINDOW_AUTOSIZE );        cvShowImage("desert", pData);       cvWaitKey(0);    // 释放内存资源    cvReleaseImage(&pData);    cvReleaseImage(&pLogo);    return 0;}