API

parallelproj.backend.calc_chunks(nLORs: int, num_chunks: int) → list[int][source]

calculate indices to split an array of length nLORs into num_chunks chunks

example: splitting an array of length 10 into 3 chunks returns [0,4,7,10]

parallelproj.backend.get_array_module(array) → module[source]

return module of a cupy or numpy array

Parameters:

array (cupy or numpy array) –

Return type:

cupy or numpy module

parallelproj.backend.joseph3d_back(xstart: ndarray[Any, dtype[float32]], xend: ndarray[Any, dtype[float32]], back_img: ndarray[Any, dtype[float32]], img_origin: ndarray[Any, dtype[float32]], voxsize: ndarray[Any, dtype[float32]], sino: ndarray[Any, dtype[float32]], threadsperblock: int = 32, num_chunks: int = 1) → None[source]

Non-TOF Joseph 3D forward projector

Parameters:

  • xstart (XPFloat32Array (float32 numpy or cupy array)) – start world coordinates of the LORs, shape (nLORs, 3)

  • xend (XPFloat32Array (float32 numpy or cupy array)) – end world coordinates of the LORs, shape (nLORs, 3)

  • back_img (XPFloat32Array (float32 numpy or cupy array)) – output array for the back projection

  • img_origin (XPFloat32Array (float32 numpy or cupy array)) – containing the world coordinates of the image origin (voxel [0,0,0])

  • voxsize (XPFloat32Array (float32 numpy or cupy array)) – array containing the voxel size

  • sino (XPFloat32Array (float32 numpy or cupy array)) – array of length nLORs containing the values to be back projected

  • threadsperblock (int, optional) – by default 32

  • num_chunks (int, optional) – break down the back projection in hybrid mode into chunks to save memory on the GPU, by default 1

parallelproj.backend.joseph3d_back_tof_lm(xstart: ndarray[Any, dtype[float32]], xend: ndarray[Any, dtype[float32]], back_img: ndarray[Any, dtype[float32]], img_origin: ndarray[Any, dtype[float32]], voxsize: ndarray[Any, dtype[float32]], lst: ndarray[Any, dtype[float32]], tofbin_width: float, sigma_tof: ndarray[Any, dtype[float32]], tofcenter_offset: ndarray[Any, dtype[float32]], nsigmas: float, tofbin: ndarray[Any, dtype[int16]], threadsperblock: int = 32, num_chunks: int = 1) → None[source]

TOF Joseph 3D listmode back projector

Parameters:

  • xstart (XPFloat32Array (float32 numpy or cupy array)) – start world coordinates of the LORs, shape (nLORs, 3)

  • xend (XPFloat32Array (float32 numpy or cupy array)) – end world coordinates of the LORs, shape (nLORs, 3)

  • back_img (XPFloat32Array (float32 numpy or cupy array)) – output array to be back projected

  • img_origin (XPFloat32Array (float32 numpy or cupy array)) – containing the world coordinates of the image origin (voxel [0,0,0])

  • voxsize (XPFloat32Array (float32 numpy or cupy array)) – array containing the voxel size

  • lst (XPFloat32Array (float32 numpy or cupy array)) – “list” of values to be projected

  • threadsperblock (int, optional) – by default 32

  • sigma_tof (XPFloat32Array (float32 numpy or cupy array)) – sigma of Gaussian TOF kernel in spatial units (same units as xstart) can be an array of length 1 -> same sigma for all LORs or an array of length nLORs -> LOR dependent sigma

  • tofcenter_offset (XPFloat32Array (float32 numpy or cupy array)) – center offset of the central TOF bin in spatial units (same units as xstart) can be an array of length 1 -> same offset for all LORs or an array of length nLORs -> LOR dependent offset

  • nsigmas (float) – number of sigmas to consider when Gaussian kernel is evaluated (truncated)

  • tofbin (XPShortArray) – array containing the tof bin of the events

  • num_chunks (int, optional) – break down the projection in hybrid mode into chunks to save memory on the GPU, by default 1

  • tofbin_width (float) – width of the TOF bin in spatial units (same units as xstart)

parallelproj.backend.joseph3d_back_tof_sino(xstart: ndarray[Any, dtype[float32]], xend: ndarray[Any, dtype[float32]], back_img: ndarray[Any, dtype[float32]], img_origin: ndarray[Any, dtype[float32]], voxsize: ndarray[Any, dtype[float32]], sino: ndarray[Any, dtype[float32]], tofbin_width: float, sigma_tof: ndarray[Any, dtype[float32]], tofcenter_offset: ndarray[Any, dtype[float32]], nsigmas: float, ntofbins: int, threadsperblock: int = 32, num_chunks: int = 1) → None[source]

TOF Joseph 3D sinogram forward projector

Parameters:

  • xstart (XPFloat32Array (float32 numpy or cupy array)) – start world coordinates of the LORs, shape (nLORs, 3)

  • xend (XPFloat32Array (float32 numpy or cupy array)) – end world coordinates of the LORs, shape (nLORs, 3)

  • back_img (XPFloat32Array (float32 numpy or cupy array)) – output array to be back projected

  • img_origin (XPFloat32Array (float32 numpy or cupy array)) – containing the world coordinates of the image origin (voxel [0,0,0])

  • voxsize (XPFloat32Array (float32 numpy or cupy array)) – array containing the voxel size

  • sino (XPFloat32Array (float32 numpy or cupy array)) – TOF sinogram of size (nLORs*ntofbins) to be back projected

  • threadsperblock (int, optional) – by default 32

  • sigma_tof (XPFloat32Array (float32 numpy or cupy array)) – sigma of Gaussian TOF kernel in spatial units (same units as xstart) can be an array of length 1 -> same sigma for all LORs or an array of length nLORs -> LOR dependent sigma

  • tofcenter_offset (XPFloat32Array (float32 numpy or cupy array)) – center offset of the central TOF bin in spatial units (same units as xstart) can be an array of length 1 -> same offset for all LORs or an array of length nLORs -> LOR dependent offset

  • nsigmas (float) – number of sigmas to consider when Gaussian kernel is evaluated (truncated)

  • ntofbins (int) – total number of TOF bins

  • num_chunks (int, optional) – break down the projection in hybrid mode into chunks to save memory on the GPU, by default 1

  • tofbin_width (float) – width of the TOF bin in spatial units (same units as xstart)

parallelproj.backend.joseph3d_fwd(xstart: ndarray[Any, dtype[float32]], xend: ndarray[Any, dtype[float32]], img: ndarray[Any, dtype[float32]], img_origin: ndarray[Any, dtype[float32]], voxsize: ndarray[Any, dtype[float32]], img_fwd: ndarray[Any, dtype[float32]], threadsperblock: int = 32, num_chunks: int = 1) → None[source]

Non-TOF Joseph 3D forward projector

Parameters:

  • xstart (XPFloat32Array (float32 numpy or cupy array)) – start world coordinates of the LORs, shape (nLORs, 3)

  • xend (XPFloat32Array (float32 numpy or cupy array)) – end world coordinates of the LORs, shape (nLORs, 3)

  • img (XPFloat32Array (float32 numpy or cupy array)) – containing the 3D image to be projected

  • img_origin (XPFloat32Array (float32 numpy or cupy array)) – containing the world coordinates of the image origin (voxel [0,0,0])

  • voxsize (XPFloat32Array (float32 numpy or cupy array)) – array containing the voxel size

  • img_fwd (XPFloat32Array (float32 numpy or cupy array)) – output array of length nLORs for storing the forward projection

  • threadsperblock (int, optional) – by default 32

  • num_chunks (int, optional) – break down the projection in hybrid mode into chunks to save memory on the GPU, by default 1

parallelproj.backend.joseph3d_fwd_tof_lm(xstart: ndarray[Any, dtype[float32]], xend: ndarray[Any, dtype[float32]], img: ndarray[Any, dtype[float32]], img_origin: ndarray[Any, dtype[float32]], voxsize: ndarray[Any, dtype[float32]], img_fwd: ndarray[Any, dtype[float32]], tofbin_width: float, sigma_tof: ndarray[Any, dtype[float32]], tofcenter_offset: ndarray[Any, dtype[float32]], nsigmas: float, tofbin: ndarray[Any, dtype[int16]], threadsperblock: int = 32, num_chunks: int = 1) → None[source]

TOF Joseph 3D listmode forward projector

Parameters:

  • xstart (XPFloat32Array (float32 numpy or cupy array)) – start world coordinates of the LORs, shape (nLORs, 3)

  • xend (XPFloat32Array (float32 numpy or cupy array)) – end world coordinates of the LORs, shape (nLORs, 3)

  • img (XPFloat32Array (float32 numpy or cupy array)) – containing the 3D image to be projected

  • img_origin (XPFloat32Array (float32 numpy or cupy array)) – containing the world coordinates of the image origin (voxel [0,0,0])

  • voxsize (XPFloat32Array (float32 numpy or cupy array)) – array containing the voxel size

  • img_fwd (XPFloat32Array (float32 numpy or cupy array)) – output array of size (xstart.shape[0] / nevents) for storing the forward projection

  • tofbin_width (float) – width of the TOF bin in spatial units (same units as xstart)

  • sigma_tof (XPFloat32Array (float32 numpy or cupy array)) – sigma of Gaussian TOF kernel in spatial units (same units as xstart) can be an array of length 1 -> same sigma for all LORs or an array of length nLORs -> LOR dependent sigma

  • tofcenter_offset (XPFloat32Array (float32 numpy or cupy array)) – center offset of the central TOF bin in spatial units (same units as xstart) can be an array of length 1 -> same offset for all LORs or an array of length nLORs -> LOR dependent offset

  • nsigmas (float) – number of sigmas to consider when Gaussian kernel is evaluated (truncated)

  • tofbin (XPShortArray) – array containing the tof bin of the events

  • threadsperblock (int, optional) – by default 32

  • num_chunks (int, optional) – break down the projection in hybrid mode into chunks to save memory on the GPU, by default 1

parallelproj.backend.joseph3d_fwd_tof_sino(xstart: ndarray[Any, dtype[float32]], xend: ndarray[Any, dtype[float32]], img: ndarray[Any, dtype[float32]], img_origin: ndarray[Any, dtype[float32]], voxsize: ndarray[Any, dtype[float32]], img_fwd: ndarray[Any, dtype[float32]], tofbin_width: float, sigma_tof: ndarray[Any, dtype[float32]], tofcenter_offset: ndarray[Any, dtype[float32]], nsigmas: float, ntofbins: int, threadsperblock: int = 32, num_chunks: int = 1) → None[source]

TOF Joseph 3D sinogram forward projector

Parameters:

  • xstart (XPFloat32Array (float32 numpy or cupy array)) – start world coordinates of the LORs, shape (nLORs, 3)

  • xend (XPFloat32Array (float32 numpy or cupy array)) – end world coordinates of the LORs, shape (nLORs, 3)

  • img (XPFloat32Array (float32 numpy or cupy array)) – containing the 3D image to be projected

  • img_origin (XPFloat32Array (float32 numpy or cupy array)) – containing the world coordinates of the image origin (voxel [0,0,0])

  • voxsize (XPFloat32Array (float32 numpy or cupy array)) – array containing the voxel size

  • img_fwd (XPFloat32Array (float32 numpy or cupy array)) – output array of size (nLORs*ntofbins) for storing the forward projection

  • tofbin_width (float) – width of the TOF bin in spatial units (same units as xstart)

  • sigma_tof (XPFloat32Array (float32 numpy or cupy array)) – sigma of Gaussian TOF kernel in spatial units (same units as xstart) can be an array of length 1 -> same sigma for all LORs or an array of length nLORs -> LOR dependent sigma

  • tofcenter_offset (XPFloat32Array (float32 numpy or cupy array)) – center offset of the central TOF bin in spatial units (same units as xstart) can be an array of length 1 -> same offset for all LORs or an array of length nLORs -> LOR dependent offset

  • nsigmas (float) – number of sigmas to consider when Gaussian kernel is evaluated (truncated)

  • ntofbins (int) – total number of TOF bins

  • threadsperblock (int, optional) – by default 32

  • num_chunks (int, optional) – break down the projection in hybrid mode into chunks to save memory on the GPU, by default 1