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rot[:, 1, 1] = torch.squeeze(y * yC + ca)
rot[:, 1, 2] = torch.squeeze(yzC - xs)
rot[:, 2, 0] = torch.squeeze(zxC - ys)
rot[:, 2, 1] = torch.squeeze(yzC + xs)
rot[:, 2, 2] = torch.squeeze(z * zC + ca)
rot[:, 3, 3] = 1
return rot
class ConvBlock(nn.Module):
"""Layer to perform a convolution followed by ELU"""
def __init__(self, in_channels, out_channels):
super(ConvBlock, self).__init__()
self.conv = Conv3x3(in_channels, out_channels)
self.nonlin = nn.ELU(inplace=True)
def forward(self, x):
out = self.conv(x)
out = self.nonlin(out)
return out
class Conv3x3(nn.Module):
"""Layer to pad and convolve input"""
def __init__(self, in_channels, out_channels, use_refl=True):
super(Conv3x3, self).__init__()
if use_refl:
self.pad = nn.ReflectionPad2d(1)
else:
self.pad = nn.ZeroPad2d(1)
self.conv = nn.Conv2d(int(in_channels), int(out_channels), 3)
def forward(self, x):
out = self.pad(x)
out = self.conv(out)
return out
class BackprojectDepth(nn.Module):
"""Layer to transform a depth image into a point cloud"""
def __init__(self, batch_size, height, width):
super(BackprojectDepth, self).__init__()
self.batch_size = batch_size
self.height = height
self.width = width
meshgrid = np.meshgrid(range(self.width), range(self.height), indexing='xy')
self.id_coords = np.stack(meshgrid, axis=0).astype(np.float32)
self.id_coords = nn.Parameter(torch.from_numpy(self.id_coords), requires_grad=False)
self.ones = nn.Parameter(torch.ones(self.batch_size, 1, self.height * self.width), requires_grad=False)
self.pix_coords = torch.unsqueeze(torch.stack([self.id_coords[0].view(-1), self.id_coords[1].view(-1)], 0), 0)
self.pix_coords = self.pix_coords.repeat(batch_size, 1, 1)
self.pix_coords = nn.Parameter(torch.cat([self.pix_coords, self.ones], 1), requires_grad=False)
def forward(self, depth, inv_K):
cam_points = torch.matmul(inv_K[:, :3, :3], self.pix_coords)
cam_points = depth.view(self.batch_size, 1, -1) * cam_points
cam_points = torch.cat([cam_points, self.ones], 1)
return cam_points
class Project3D(nn.Module):
"""Layer which projects 3D points into a camera with intrinsics K and at position T"""
def __init__(self, batch_size, height, width, eps=1e-7):
super(Project3D, self).__init__()
self.batch_size = batch_size
self.height = height
self.width = width
self.eps = eps
def forward(self, points, K, T):
P = torch.matmul(K, T)[:, :3, :]
cam_points = torch.matmul(P, points)
pix_coords = cam_points[:, :2, :] / (cam_points[:, 2, :].unsqueeze(1) + self.eps)
pix_coords = pix_coords.view(self.batch_size, 2, self.height, self.width)
pix_coords = pix_coords.permute(0, 2, 3, 1)
pix_coords[..., 0] /= self.width - 1
pix_coords[..., 1] /= self.height - 1
pix_coords = (pix_coords - 0.5) * 2
return pix_coords
def upsample(x):
"""Upsample input tensor by a factor of 2"""
return F.interpolate(x, scale_factor=2, mode="nearest")
def get_smooth_loss(disp, img):
"""Computes the smoothness loss for a disparity image
The color image is used for edge-aware smoothness