检索从扭曲图像中获取的像素的原始坐标

时间:2013-01-15 17:33:52

标签: image-processing opencv distortion 3d-reconstruction perspectivecamera

我从 sourceImage 中提取了四个角:

src_vertices[0] = corners[upperLeft];
src_vertices[1] = corners[upperRight];   
src_vertices[2] = corners[downLeft];
src_vertices[3] = corners[downRight];

这四个角被扭曲为 destinationImage ,如:

dst_vertices[0] = Point(0,0);
dst_vertices[1] = Point(width, 0); 
dst_vertices[2] = Point(0, height);
dst_vertices[3] = Point(width, height);

Mat warpPerspectiveMatrix = getPerspectiveTransform(src_vertices, dst_vertices);
cv::Size size_d =  Size(width, height);
cv::Mat DestinationImage(width,height,CV_8UC3);
warpPerspective(sourceImage, destinationImage, warpPerspectiveMatrix, size_d, INTER_LINEAR, BORDER_CONSTANT);

现在我的问题是:

我有从 destinationImage 取得的点p(x,y)如何在原始sourceImage中检索此点的坐标

换句话说,我想使用warpPerspectiveMatrix来完成getPerspectiveTransform的相反工作

1 个答案:

答案 0 :(得分:5)

您想要逆透视变换。如果您的原始变换是S-> S',则需要变换矩阵S' - > S

Mat InversewarpPerspectiveMatrix = getPerspectiveTransform(dst_vertices, src_vertices);

然后你制作一个SPARSE矩阵

Mat PerspectiveCoordinates containing the vector x,y.

最后你想打电话

PerspectiveTransform(PerspectiveCoordinates,OriginalCoordinates,InversewarpPerspectiveMatrix)