1、Mat与IplImage之间的相互转换；
//IplImage—>Mat
//EXAMPLE：
//浅拷贝：
IplImage* pBinary=cvLoadImage("c://temp.jpg",0);
Mat Img;
Img=cvarrToMat(pBinary);
//深拷贝只需要再在Mat里创建一个新的Mat对象，然后进行数据的复制，再用上述的函数进行数据头的复制（浅拷贝）：
IplImage* pBinary=cvLoadImage("c://temp.jpg", 0);
Mat ImgTemp;
Img=cvarrToMat(pBinary);
Mat Img = ImgTemp.clone();
//Mat—>IplImage
//EXAMPLE:
//浅拷贝:
Mat Img=imread("1.jpg");
IplImage* pBinary = &IplImage(Img);
//深拷贝只要再加一次复制数据：
IplImage *input = cvCloneImage(pBinary);
2、随机数；
标准库提供了随机函数std::srand,std::rand来生成随机数；
std::srand(unsigned(time(NULL)); std::rand(); //生成随机数；
3、矩阵缩放；
opencv的图像缩放函数为cv::resize();
Resizes an image. C++: void resize(InputArray src, OutputArray dst, Size dsize, double fx=0, double fy=0, int interpolation=INTER_LINEAR ) Python: cv2.resize(src, dsize[, dst[, fx[, fy[, interpolation]]]]) → dst C: void cvResize(const CvArr* src, CvArr* dst, int interpolation=CV_INTER_LINEAR ) Python: cv.Resize(src, dst, interpolation=CV_INTER_LINEAR) → None Parameters: src – Source image. dst – Destination image. It has the size dsize (when it is non-zero) or the size computed from src.size() , fx , and fy . The type of dst is the same as of src . dsize – Destination image size. If it is zero, it is computed as: Either dsize or both fx and fy must be non-zero. fx – Scale factor along the horizontal axis. When it is 0, it is computed as fy – Scale factor along the vertical axis. When it is 0, it is computed as interpolation – Interpolation method: INTER_NEAREST - a nearest-neighbor interpolation INTER_LINEAR - a bilinear interpolation (used by default) INTER_AREA - resampling using pixel area relation. It may be a preferred method for image decimation, as it gives moire’-free results. But when the image is zoomed, it is similar to the INTER_NEAREST method. INTER_CUBIC - a bicubic interpolation over 4x4 pixel neighborhood INTER_LANCZOS4 - a Lanczos interpolation over 8x8 pixel neighborhood：
使用方法：
cv::Mat(srcIMg,dstImg,dstImg.Size,0,0,cv::INTER_CUBIC); //fx,fy，将按照dstImg.size与srcImg的比值来进行设置 或者 cv::Mat(srcImg,dstImg,cv::Size(), 0.5,0.5,cv::INTER_CUBIC);