pjrec(1)

reconstruction from projections

Section 1 ctsim bookworm source

Description

pjrec

NAME

pjrec - reconstruction from projections

SYNOPSIS

pjrec projection-file image-file nx-image ny-image [OPTIONS]

DESCRIPTION

pjrec takes projection data from raysum-fileP and produces an (IF) image file image-file, of size nx-image by ny-image pixels, containing the reconstructed image.

OPTIONS

pjrec accepts the following options, which control the reconstruction algorithm:

--interp

Interpolation method during backprojection

nearest

Nearest neighbor interpolation

linear

Linear interpolation

--preinterpolate

Preinterpolation factor (default = 1). Used only with frequency-based filtering

--filter

Filter name

abs_bandlimit

			Abs * Bandlimiting (default)
	abs_sinc		Abs * Sinc
	abs_cosine		Abs * Cosine
	abs_hamming		Abs * Hamming
	shepp		Shepp-Logan
	bandlimit		Bandlimiting
	sinc		Sinc
	cosine		Cosine
	triangle		Triangle
	hamming		Hamming

--filter-method

Filter method before backprojections

	convolution		Spatial filtering (default)
	fourier		Frequency filtering with discete fourier
	fourier_table		Frequency filtering with table lookup fourier
	fft		Fast Fourier Transform

--zeropad n

Set zeropad level (default = 0). set n to number of powers to two to pad

--filter-generation

Filter Generation mode

direct

Use direct filter in spatial or frequency domain (default)

inverse_fourier

Use inverse fourier transform of inverse filter

--backproj

Backprojection Method

trig

			Trigometric functions at every point
	table		Trigometric functions with precalculated table
	diff		Difference method
	diff2		Optimized difference method (default)

idiff2

Optimized difference method with integer math

idiff3

Highly-optimized difference method with integer math

--filter-param

Alpha level for Hamming filter

--trace

Set tracing to level:

none

			No tracing (default)
	console		Text level tracing

--verbose Turn on verbose mode
--debug Turn on debug mode
--version Print version
--help Print a terse help message

AUTHORS

Kevin Rosenberg, M.D. <kevin@ctsim.org>

HISTORY

CTSim was begun in 1983 using MS-DOS and an EGA display adapter. In 1999 it was ported to GNU/Linux and later ported to Microsoft Windows.