OpenCV基础篇——图形图像旋转

以前在做图像处理的时候用到了图像的旋转，opencv自带的flip函数只能180度，因为需要旋转任意角度，顺时针和逆时针的情况，所以去找了些效果比较好的函数来实现。网上有的旋转函数有内存泄露的现象，现在把修改过我用过的无内存泄露的函数分享一下：

一：

void  cvRotate(IplImage* src,int angle)
 
{ 
 
IplImage * dst = 0;
 
 
 
dst = cvCloneImage (src);
 
double delte = 1.0;
 
double factor = 1.0;
 
float m[6];
 

 
CvMat M = cvMat( 2, 3, CV_32F, m );
 
int w = src->width;
 
int h = src->height;
 
 
 
m[0] = (float)(factor*cos(-angle*2*CV_PI/180.));
 
m[1] = (float)(factor*sin(-angle*2*CV_PI/180.));
 
m[2] = w*0.5f;
 
m[3] = -m[1];
 
m[4] = m[0];
 
m[5] = h*0.5f;
 
cvZero (dst);
 
cvGetQuadrangleSubPix( src, dst, &M);
*src = *dst;
}

二：

IplImage*  cvRotate2(IplImage* src,IplImage * dst )
{
	
	double delte = 1.0;
 
	double factor =1.0;

   float m[6];
 

int angle =90;

int tempLength = (int)sqrt(float(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;    
    

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

cvCopy(src, temp, NULL);   

int w = temp->width;   
int h = temp->height;  
 
m[0] = (float) cos( angle * CV_PI / 180.);   
m[1] = (float) sin( angle * CV_PI / 180.);   
 
m[2] = w*0.5f;
 
m[3] = -m[1];
 
m[4] = m[0];
 
m[5] = h*0.5f;
 

 CvMat M = cvMat(2, 3, CV_32F, m);  
cvGetQuadrangleSubPix( temp,dst, &M);

 cvReleaseImage(&temp);
return dst;

}

三：

IplImage *cvRotate(IplImage *imgSrc)
{  
    double degree = 270; // rotate 30 degree  
    double angle = degree  * CV_PI / 180.; // angle in radian  
    double a = sin(angle), b = cos(angle); // sine and cosine of angle  
  
    
    int w_src = imgSrc->width;  
    int h_src = imgSrc->height;  

   
   int w_dst = int(h_src * fabs(a) + w_src * fabs(b));  
   int h_dst = int(w_src * fabs(a) + h_src * fabs(b));  
  
   // map matrix for WarpAffine, stored in statck array  
    double map[6];  
    CvMat map_matrix = cvMat(2, 3, CV_64FC1, map);  
  
    // Rotation center needed for cv2DRotationMatrix  
    CvPoint2D32f pt = cvPoint2D32f(w_src / 2, h_src / 2);  
    cv2DRotationMatrix(pt, degree, 1.0, &map_matrix);  
  
    // Adjust rotation center to dst's center,  
    // otherwise you will get only part of the result  
    map[2] += (w_dst - w_src) / 2;  
    map[5] += (h_dst - h_src) / 2;  
  
  
    // We need a destination image  
  
    IplImage *imgDst = cvCreateImage(cvSize(w_dst, h_dst), 8, 3);  
    cvWarpAffine(  
        imgSrc,   
        imgDst,  
        &map_matrix,  
        CV_INTER_LINEAR | CV_WARP_FILL_OUTLIERS,  
        cvScalarAll(0)  
        );  
   
	
     return imgDst;

}

四：

cvTranspose( const CvArr* src, CvArr* dst );的使用

五：推荐

void  cvRotate(IplImage* img,IplImage *img_rotate,int degree)
{
	
 //旋转中心为图像中心  
    CvPoint2D32f center;    
    center.x=float (img->width/2.0+0.5);  
    center.y=float (img->height/2.0+0.5);  
    //计算二维旋转的仿射变换矩阵  
    float m[6];              
    CvMat M = cvMat( 2, 3, CV_32F, m );  
    cv2DRotationMatrix( center, degree,1, &M);  
    //变换图像，并用黑色填充其余值  
    cvWarpAffine(img,img_rotate, &M,CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS,cvScalarAll(0) );  
}