o V h @sddlmZddlZddlmmZddlmZddedededee fd d Z dd e d e de defddZ ddeede fddZ dS))OptionalN)Tensorbilinearimg absolute_gridmode align_cornersc Cs||jdd\}}|jddgdd\}}d||dd}|dkr,d||dd}tj||gdd}tj||||dS)z_Same as torch's grid_sample, with absolute pixel coordinates instead of normalized coordinates.Ndim)rr)shapesplittorchcatF grid_sample) rrrrhwxgridygridnormalized_gridrZ/var/www/vscode/kcb/lib/python3.10/site-packages/torchvision/models/optical_flow/_utils.pyrsrcpu batch_sizerrdevicecCs^t|}tjtj||dtj||ddd}tj|ddddd}|d|dddS)N)rij)indexingr rr r )rrmeshgridarangestackfloatrepeat)rrrrcoordsrrrmake_coords_grids $r'up_maskfactorc Cs|j\}}}}||||}}|dur!|tj|||fdddS||dd||||}tj|dd}tj||d dd ||ddd||} tj|| dd} | d dd dd d  ||||S)a,Upsample flow by the input factor (default 8). If up_mask is None we just interpolate. If up_mask is specified, we upsample using a convex combination of its weights. See paper page 8 and appendix B. Note that in appendix B the picture assumes a downsample factor of 4 instead of 8. NrT)sizerrr rr ) kernel_sizepaddingr) rr interpolateviewrsoftmaxunfoldsumpermutereshape) flowr)r*r num_channelsrrnew_hnew_wupsampled_flowrrr upsample_flows& r>)rN)r)Nr()typingrrtorch.nn.functionalnn functionalrrstrboolrintr'r>rrrrs