opencv 拉伸、扭曲、旋转图像-透视变换

 /* Warps image with perspective (projective) transform */

CVAPI(void)  cvWarpPerspective( const CvArr* src, CvArr* dst, const CvMat* map_matrix,
                                int flags CV_DEFAULT(CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS),
                                CvScalar fillval CV_DEFAULT(cvScalarAll(0)) );

参数与cvWarpAffine()相同，有一个小的但很重要的区别是所采用的映射矩阵必须是3x3的

CvMat* cvGetPerspectiveTransform(
	const CvPoint2D32f* pts_src,
	const CvPoint2D32f* pts_dst,
	CvMat* map_matrix
	);

这里的pts_src和pts_dst是四个点的数组

void imageRotationP(void)
{
	CvPoint2D32f srcQuad[4], dstQuad[4];
	CvMat* warp_matrix = cvCreateMat(3, 3, CV_32FC1);
	IplImage *src, *dst;

	src=cvLoadImage("lena.jpg");
	dst=cvCloneImage(src);
	dst->origin = src->origin;
	cvZero(dst);

	srcQuad[0].x=0;//src Top left
	srcQuad[0].y=0;
	srcQuad[1].x=src->width-1;//src Top right
	srcQuad[1].y=0;
	srcQuad[2].x=0;//src Bottom left
	srcQuad[2].y=src->height-1;
	srcQuad[3].x=src->width-1;//src Bottom right
	srcQuad[3].y=src->height-1;

	dstQuad[0].x=src->width*0.05;//dst Top left
	dstQuad[0].y=src->height*0.33;
	dstQuad[1].x=src->width*0.9;//dst Top right
	dstQuad[1].y=src->height*0.25;
	dstQuad[2].x=src->width*0.2;//dst Bottom left
	dstQuad[2].y=src->height*0.7;
	dstQuad[3].x=src->width*0.9;//dst Bottom right
	dstQuad[3].y=src->height*0.9;

	cvGetPerspectiveTransform(
		srcQuad, dstQuad, warp_matrix
		);

	cvWarpPerspective(src, dst, warp_matrix);
	cvNamedWindow("Perspective_Warp", 1);
	cvShowImage("Perspective_Warp", dst);
	cvWaitKey(0);
	cvReleaseImage(&src);
	cvReleaseImage(&dst);
	cvReleaseMat(&warp_matrix);
}

opencv 拉伸、扭曲、旋转图像-仿射变换

http://blog.csdn.net/u012005313/article/details/46714637