astra_cuda_bp_scaling_factor

odl.tomo.backends.astra_cuda.astra_cuda_bp_scaling_factor(proj_space, vol_space, geometry)

Volume scaling accounting for differing adjoint definitions.

ASTRA defines the adjoint operator in terms of a fully discrete setting (transposed "projection matrix") without any relation to physical dimensions, which makes a re-scaling necessary to translate it to spaces with physical dimensions.

Behavior of ASTRA changes slightly between versions, so we keep track of it and adapt the scaling accordingly.