/*
* ( AT A + lambda I) x = b
*/
static void maps_apply_pinverse(const void* _data, float lambda, complex float* dst, const complex float* src)
{
struct maps_data* data = (struct maps_data*)_data;
maps_init_normal(data);
md_zsadd(DIMS, data->img_dims, data->norm, data->norm, lambda);
md_zdiv(DIMS, data->img_dims, dst, src, data->norm);
md_zsadd(DIMS, data->img_dims, data->norm, data->norm, -lambda);
}
/**
* 1/2 || Ax - b ||^2 + rho/2 || x - y ||^2
*
* x = (ATA + lI)^-1 b
*
* X = 1 / (pat^2 + l) B
*
*/
static void ufft_apply_pinverse(const linop_data_t* _data, float rho, complex float* dst, const complex float* src)
{
const struct ufft_data* data = CONTAINER_OF(_data, const struct ufft_data, base);
md_zsadd(DIMS, data->pat_dims, data->pat, data->pat, rho);
linop_forward(data->fft_op, DIMS, data->ksp_dims, dst, DIMS, data->ksp_dims, src);
md_zdiv2(DIMS, data->ksp_dims, data->ksp_strs, dst, data->ksp_strs, dst, data->pat_strs, data->pat);
linop_adjoint(data->fft_op, DIMS, data->ksp_dims, dst, DIMS, data->ksp_dims, dst);
md_zsadd(DIMS, data->pat_dims, data->pat, data->pat, -rho);
}
/**
* Compute Strang's circulant preconditioner
*
* Strang's reconditioner is simply the cropped psf in the image domain
*
*/
static complex float* compute_precond(unsigned int N, const long* pre_dims, const long* pre_strs, const long* psf_dims, const long* psf_strs, const complex float* psf, const complex float* linphase)
{
int ND = N + 1;
unsigned long flags = FFT_FLAGS;
complex float* pre = md_alloc(ND, pre_dims, CFL_SIZE);
complex float* psft = md_alloc(ND, psf_dims, CFL_SIZE);
// Transform psf to image domain
ifftuc(ND, psf_dims, flags, psft, psf);
// Compensate for linear phase to get cropped psf
md_clear(ND, pre_dims, pre, CFL_SIZE);
md_zfmacc2(ND, psf_dims, pre_strs, pre, psf_strs, psft, psf_strs, linphase);
md_free(psft);
// Transform to Fourier domain
fftuc(N, pre_dims, flags, pre, pre);
md_zabs(N, pre_dims, pre, pre);
md_zsadd(N, pre_dims, pre, pre, 1e-3);
return pre;
}
static void noir_calc_weights(const long dims[3], complex float* dst)
{
unsigned int flags = 0;
for (int i = 0; i < 3; i++)
if (1 != dims[i])
flags = MD_SET(flags, i);
klaplace(3, dims, flags, dst);
md_zsmul(3, dims, dst, dst, 220.);
md_zsadd(3, dims, dst, dst, 1.);
md_zspow(3, dims, dst, dst, -16.); // 1 + 222. \Laplace^16
}
