Projective Spatial Transformer: preliminary code explore

[msrepo]

Quick setup and run https://github.com/gaocong13/Projective-Spatial-Transformers

RuntimeError: Subtraction, the - operator, with a bool tensor is not supported. If you are trying to invert a mask, use the ~ or logical_not() operator instead.
from https://stackoverflow.com/questions/65637222/runtimeerror-subtraction-the-operator-with-a-bool-tensor-is-not-supported
replace

    mask_c0 = mask_d2 * mask_d0_d1
    mask_c1 = mask_d2 * (1 - mask_d0_d1)
    mask_c2 = (1 - mask_d2) * mask_d0_nd1
    mask_c3 = (1 - mask_d2) * (1 - mask_d0_nd1)

with

    mask_c0 = mask_d2 * mask_d0_d1
    mask_c1 = mask_d2 * ~(mask_d0_d1)
    mask_c2 = ~(mask_d2) * mask_d0_nd1
    mask_c3 = ~(mask_d2) * ~(mask_d0_nd1) 

[msrepo]

Tasks

• Apply ProST to obtain X-ray from CT

[msrepo]

Understand these predefined hard-coded geometry

    # Pre-defined hard coded geometry
    src_det = 1020
    iso_center = 400
    det_size = 128
    pix_spacing = 0.73 * 512 / det_size #0.194*1536 / det_size
    step_size = 1.75
    vol_size = CT_vol.shape[0]

    norm_factor = (vol_size * vol_spacing / 2)
    src = (src_det - iso_center) / norm_factor
    det = -iso_center / norm_factor
    pix_spacing = pix_spacing / norm_factor
    step_size = step_size / norm_factor

Normalizing factor: normalizes the input volume such that it occupies the normalized physical space (-1,1)

[msrepo]

Expected:

Got:

Using Camera Parameters: