nfft_radon: Radon transform using NFFT

In gzt/rNFFT: Fast Fourier Transform at Nonequispaced Nodes

Description

A radon transformation using the non-equispaced fast Fourier transform (NFFT). Requires a square image.

Usage

nfft_radon(
  image,
  theta = 181,
  rho = 2 * round(sqrt(sum((dim(image))^2))/2) + 1,
  fn = "polar"
)

nfft_inv_radon(image, n, iter = 10, fn = "polar")

Arguments

image	square image
theta	Number of theta slices
rho	Number of rho slices
fn	Whether to use polar or linotype (polar by default)
n	size of image
iter	number of iterations for inverse

Functions

• nfft_inv_radon: Inverse Radon Transform using NFFT

Examples

data(phantom_example)
image(phantom_example)
P_radon <- nfft_radon(phantom_example, 514, 514, fn = "polar")
image(P_radon)
P_inv <- nfft_inv_radon((P_radon), n = 257, iter = 2, fn = "polar")
image(P_inv)

gzt/rNFFT documentation built on April 15, 2020, 6:07 p.m.