Registration

nanodrr.registration ¶

Registration ¶

Registration(
    subject: Subject,
    rt_inv: Float[Tensor, "B 4 4"],
    k_inv: Float[Tensor, "B 3 3"],
    sdd: Float[Tensor, B],
    height: int,
    width: int,
    eps: float = 1e-08,
)

Differentiable 2D/3D registration module.

Optimize poses in SE(3) by aligning rendered X-rays with real target X-ray images. Initial intrinsic and extrinsic matrices are fixed at construction. Optimizable parameters are parameterized as perturbations.

PARAMETER	DESCRIPTION
`subject`	The volume to render DRRs from during optimization. TYPE: `Subject`
`rt_inv`	Initial inverse extrinsic (camera-to-world) matrix. TYPE: `Float[Tensor, 'B 4 4']`
`k_inv`	Inverse intrinsic camera matrix. TYPE: `Float[Tensor, 'B 3 3']`
`sdd`	Source-to-detector distance. TYPE: `Float[Tensor, B]`
`height`	Output image height in pixels. TYPE: `int`
`width`	Output image width in pixels. TYPE: `int`
`eps`	Small constant for numerical stability. TYPE: `float` DEFAULT: `1e-08`

Source code in src/nanodrr/registration/registration.py

def __init__(
    self,
    subject: Subject,
    rt_inv: Float[torch.Tensor, "B 4 4"],
    k_inv: Float[torch.Tensor, "B 3 3"],
    sdd: Float[torch.Tensor, "B"],
    height: int,
    width: int,
    eps: float = 1e-8,
) -> None:
    super().__init__()
    self.subject = subject
    self.register_buffer("rt_inv", rt_inv)
    self.register_buffer("k_inv", k_inv)
    self.register_buffer("sdd", sdd)
    self.height = height
    self.width = width

    # Parameterize the perturbation about the isocenter rather than the world origin
    c = transform_point(rt_inv.inverse(), subject.isocenter[None])
    self.register_buffer("pivot", self._make_translation(c))
    self.register_buffer("pivot_inv", self._make_translation(-c))

    # Parameterization of the perturbation
    self._rot = torch.nn.Parameter(eps * torch.randn(1, 3, device=c.device))
    self._xyz = torch.nn.Parameter(eps * torch.randn(1, 3, device=c.device))

pose `property` ¶

pose: Float[Tensor, 'B 4 4']

Change of basis about the volume's isocenter.

rescale_ ¶

rescale_(scale: float) -> None

Change the rendering resolution by rescaling the camera's intrinsics.