o oi @sjddlZddlZddlmZddlmZddlmZddejded e d ejfd d Z Gd ddej Z dS)N)nn)filter2d)create_meshgridffffff?image kernel_sizehreturnc Cst|tjstdt|t|jdkstd|j|ddkr(tdt t |jd|jdt |d}t ||d|j |jd }|t |d8}t|dd d d d df|dd d d d d f}t|| d}t|}|}t|}t|D]A} t||d d } | t| } tj| dd} t| dkdd} | dkr|S| |d} || | | 7}t| d k||}q|S)aApproximates the Manhattan distance transform of images using cascaded convolution operations. The value at each pixel in the output represents the distance to the nearest non-zero pixel in the image image. It uses the method described in :cite:`pham2021dtlayer`. The transformation is applied independently across the channel dimension of the images. Args: image: Image with shape :math:`(B,C,H,W)`. kernel_size: size of the convolution kernel. h: value that influence the approximation of the min function. Returns: tensor with shape :math:`(B,C,H,W)`. Example: >>> tensor = torch.zeros(1, 1, 5, 5) >>> tensor[:,:, 1, 2] = 1 >>> dt = kornia.contrib.distance_transform(tensor) z&image type is not a torch.Tensor. Got z-Invalid image shape, we expect BxCxHxW. Got: rz"Kernel size must be an odd number.rF)normalized_coordinatesdevicedtypeN replicate) border_typeg)posinfg?) isinstancetorchTensor TypeErrortypelenshape ValueErrormathceilmaxfloorrrrhypotexp unsqueeze zeros_likeclone ones_likerangerlog nan_to_numwheresum) rrr n_itersgridkerneloutboundary signal_onesicdtmaskoffsetr5U/home/ubuntu/.local/lib/python3.10/site-packages/kornia/contrib/distance_transform.pydistance_transforms8  *4     r7csFeZdZdZd dededdffdd Zd ejdejfd d Z Z S)DistanceTransformzModule that approximates the Manhattan (city block) distance transform of images using convolutions. Args: kernel_size: size of the convolution kernel. h: value that influence the approximation of the min function. rrrr r Ncst||_||_dS)N)super__init__rr )selfrr  __class__r5r6r:es  zDistanceTransform.__init__rcCsF|jddkr|dd|jd|jd}n|}t||j|j|S)Nr)rviewr7rr view_as)r;rimage_inr5r5r6forwardjszDistanceTransform.forwardrr) __name__ __module__ __qualname____doc__intfloatr:rrrC __classcell__r5r5r<r6r8\sr8rD) rrrkornia.filtersr kornia.utilsrrrIrJr7Moduler8r5r5r5r6s    A