Currently I still finding any similar OpenCV Cuda function which can replace cv::distanceTransform. As I know distancetransform has no direct counterpart to OpenCV cuda.
IIRC you need two passes horizontal/vertical, two passes vertical/horizontal, for L2/euclidean distance.
seems implementable, if you can do your own cuda kernels.
that’s the “worst case”. cudawarped probably has a better idea 
Not that I know of. Have you looked at NVIDIA 2D Image And Signal Performance Primitives (NPP): FilterDistanceTransform to see if it can be of any help?
There is some information using cuda programming to implement the distance Transform but its hard for me which need to take time to learn new language. Btw thanks for the reply.
I try to find from OpenCV Cuda for the implementation. Cuda programming may need some time to learn. Thanks for the reply.