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32 lines
1013 B
32 lines
1013 B
3 years ago
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import torch
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import torch.nn.functional as F
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import numpy as np
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#Ref: https://github.com/princeton-vl/RAFT/blob/master/core/utils/utils.py
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def bilinear_sampler(img, coords, mode='bilinear', mask=False):
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""" Wrapper for grid_sample, uses pixel coordinates """
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H, W = img.shape[-2:]
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xgrid, ygrid = coords.split([1,1], dim=-1)
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xgrid = 2*xgrid/(W-1) - 1
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ygrid = 2*ygrid/(H-1) - 1
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grid = torch.cat([xgrid, ygrid], dim=-1)
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img = F.grid_sample(img, grid, align_corners=True)
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if mask:
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mask = (xgrid > -1) & (ygrid > -1) & (xgrid < 1) & (ygrid < 1)
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return img, mask.float()
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return img
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def coords_grid(batch, ht, wd, device):
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coords = torch.meshgrid(torch.arange(ht, device=device), torch.arange(wd, device=device), indexing='ij')
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coords = torch.stack(coords[::-1], dim=0).float()
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return coords[None].repeat(batch, 1, 1, 1)
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def manual_pad(x, pady, padx):
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pad = (padx, padx, pady, pady)
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return F.pad(x.clone().detach(), pad, "replicate")
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