#include "cv.h"#include "highgui.h"#include "math.h"

// clockwise 为true则顺时针旋转，否则为逆时针旋转IplImage* rotateImage(IplImage* src, int angle, bool clockwise){    angle = abs(angle) % 180;if (angle > 90)    {        angle = 90 - (angle % 90);    }    IplImage* dst = NULL;int width =            (double)(src->height * sin(angle * CV_PI / 180.0)) +            (double)(src->width * cos(angle * CV_PI / 180.0 )) + 1;int height =            (double)(src->height * cos(angle * CV_PI / 180.0)) +            (double)(src->width * sin(angle * CV_PI / 180.0 )) + 1;int tempLength = sqrt(src->width * src->width + src->height * src->height) + 10;int tempX = (tempLength + 1) / 2 - src->width / 2;int tempY = (tempLength + 1) / 2 - src->height / 2;int flag = -1;

    dst = cvCreateImage(cvSize(width, height), src->depth, src->nChannels);    cvZero(dst);    IplImage* temp = cvCreateImage(cvSize(tempLength, tempLength), src->depth, src->nChannels);    cvZero(temp);

    cvSetImageROI(temp, cvRect(tempX, tempY, src->width, src->height));    cvCopy(src, temp, NULL);    cvResetImageROI(temp);

if (clockwise)        flag = 1;

float m[6];int w = temp->width;int h = temp->height;    m[0] = (float) cos(flag * angle * CV_PI / 180.);    m[1] = (float) sin(flag * angle * 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;//    CvMat M = cvMat(2, 3, CV_32F, m);    cvGetQuadrangleSubPix(temp, dst, &M);    cvReleaseImage(&temp);return dst;}

int main(int argc, char **argv){    IplImage *src = 0;    IplImage *dst = 0;

int angle = 75;

    src = cvLoadImage("test.jpg");

    dst = rotateImage(src, angle, false);    cvNamedWindow("dst", 1);    cvShowImage("dst", dst);    cvWaitKey(0);

    cvReleaseImage(&src);    cvReleaseImage(&dst);return 0;}