detector

Set up the 7 degrees-of-freedom parameters for the C-arm

Tip

The Detector is usually initialized in the DRR module and shouldn’t need to be called directly.

Detector

 Detector (sdd:float, height:int, width:int, delx:float, dely:float,
           x0:float, y0:float, reorient:torch.Tensor,
           n_subsample:int|None=None, reverse_x_axis:bool=False)

Construct a 6 DoF X-ray detector system. This model is based on a C-Arm.

	Type	Default	Details
sdd	float		Source-to-detector distance (in units length)
height	int		Y-direction length (in units pixels)
width	int		X-direction length (in units pixels)
delx	float		X-direction spacing (in units length / pixel)
dely	float		Y-direction spacing (in units length / pixel)
x0	float		Principal point x-coordinate (in units length)
y0	float		Principal point y-coordinate (in units length)
reorient	Tensor		Frame-of-reference change matrix
n_subsample	int \| None	None	Number of target points to randomly sample
reverse_x_axis	bool	False	If pose includes reflection (in E(3) not SE(3)), reverse x-axis

source

Detector.forward

 Detector.forward (extrinsic:diffdrr.pose.RigidTransform,
                   calibration:diffdrr.pose.RigidTransform)

Create source and target points for X-rays to trace through the volume.

Intrinsic matrix parsing

From a calibrated camera’s intrinsic matrix, calculate the following properties:

Focal length (in units length)
Principal point (in units length)

source

get_focal_length

 get_focal_length (intrinsic, delx:float, dely:float)

	Type	Details
intrinsic		Intrinsic matrix (3 x 3 tensor)
delx	float	X-direction spacing (in units length)
dely	float	Y-direction spacing (in units length)
Returns	float	Focal length (in units length)

source

get_principal_point

 get_principal_point (intrinsic, height:int, width:int, delx:float,
                      dely:float)

	Type	Details
intrinsic		Intrinsic matrix (3 x 3 tensor)
height	int	Y-direction length (in units pixels)
width	int	X-direction length (in units pixels)
delx	float	X-direction spacing (in units length)
dely	float	Y-direction spacing (in units length)

source

parse_intrinsic_matrix

 parse_intrinsic_matrix (intrinsic, height:int, width:int, delx:float,
                         dely:float)

	Type	Details
intrinsic		Intrinsic matrix (3 x 3 tensor)
height	int	Y-direction length (in units pixels)
width	int	X-direction length (in units pixels)
delx	float	X-direction spacing (in units length)
dely	float	Y-direction spacing (in units length)

source

make_intrinsic_matrix

 make_intrinsic_matrix (detector:__main__.Detector)