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import torch |
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import torch.nn as nn |
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device = torch.device("cuda" if torch.cuda.is_available() else "cpu") |
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backwarp_tenGrid = {} |
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def warp(tenInput, tenFlow): |
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k = (str(tenFlow.device), str(tenFlow.size())) |
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if k not in backwarp_tenGrid: |
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tenHorizontal = torch.linspace(-1.0, 1.0, tenFlow.shape[3], device=device).view( |
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1, 1, 1, tenFlow.shape[3]).expand(tenFlow.shape[0], -1, tenFlow.shape[2], -1) |
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tenVertical = torch.linspace(-1.0, 1.0, tenFlow.shape[2], device=device).view( |
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1, 1, tenFlow.shape[2], 1).expand(tenFlow.shape[0], -1, -1, tenFlow.shape[3]) |
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backwarp_tenGrid[k] = torch.cat( |
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[tenHorizontal, tenVertical], 1).to(device) |
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tenFlow = torch.cat([tenFlow[:, 0:1, :, :] / ((tenInput.shape[3] - 1.0) / 2.0), |
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tenFlow[:, 1:2, :, :] / ((tenInput.shape[2] - 1.0) / 2.0)], 1) |
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g = (backwarp_tenGrid[k] + tenFlow).permute(0, 2, 3, 1) |
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return torch.nn.functional.grid_sample(input=tenInput, grid=g, mode='bilinear', padding_mode='border', align_corners=True) |
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