OpenCV学习之图像的旋转与缩放

//图像的旋转与缩放
#include "cv.h"
#include "highgui.h"
#include "math.h"
int main(int argc, char** argv) {
IplImage* src = cvLoadImage("Lena.tif", 1);
IplImage* dst = cvCloneImage(src);
int delta = 1;
int angle = 0;
int opt = 1;//1旋转加缩放，0旋转
double factor;
cvNamedWindow("src", 1);
cvShowImage("src", src);
while (1) {
float m[6];
CvMat M = cvMat(2, 3, CV_32F, m);
int w = src->width;
int h = src->height;
if (opt)
factor = (cos(angle * CV_PI / 180.) + 1.05) * 2;
else
factor = 1;
m[0] = (float)(factor*cos(-angle * 2 * CV_PI / 180.));
m[1] = (float)(factor*sin(-angle * 2 * CV_PI / 180.));
m[3] = -m[1];
m[4] = m[0];
//将旋转中心移至图像中间
m[2] = w*0.5f;
m[5] = h*0.5f;

//dst = A*src + b
cvGetQuadrangleSubPix(src, dst, &M);//双线性插值，提取像素四边形
cvNamedWindow("dst", 1);
cvShowImage("dst", dst);
if (cvWaitKey(5) == 27)
break;
angle = (int)(angle + delta) % 360;//自动变换角度
}
return 0;
}