Method, apparatus and program for restoring phase information

A method of restoring phase information on a radiation transmitted through an object on the basis of detection data obtained by detecting intensity of the radiation emitted from a radiation source having a focal spot size σ in a position at a distance R from the object and transmitted through the object, said method comprising the steps of:

• (a) acquiring plural sets of first detection data respectively representing plural kinds of radiation image information on plural detection planes at different distances zi from the object, said plural sets of first detection data being obtained by detecting intensity of the radiation on said plural detection planes;
• (b) respectively generating plural sets of second detection data by suppressing spatial frequency components larger than 3R/2πσz with respect to said plural sets of first detection data, where z is a maximum value of zi;
• and
• (c) restoring phase information on the radiation transmitted through the object on the basis of said plural sets of second detection data so as to obtain phase data.

An apparatus for restoring phase information on radiations transmitted through an object on the basis of detection data obtained by detecting intensity of the radiations transmitted through the object, said apparatus comprising:

• a radiation source for emitting each of plural radiations having different wavelengths with energy from 16 keV to 30 keV;
• detecting means for detecting intensity of the radiation emitted from said radiation source and transmitted through the object so as to obtain detection data representing radiation image information;
• and
• phase data calculating means for restoring phase information on the radiations having different wavelengths and transmitted through the object on the basis of plural sets of detection data obtained by detecting intensity of the plural radiations so as to obtain phase data.

An apparatus for restoring phase information on a radiation transmitted through an object on the basis of detection data obtained by detecting intensity of the radiation transmitted through the object, said apparatus comprising:

• a radiation source for emitting a radiation having a predetermined wavelength with energy from 16 keV to 30 keV;
• detecting means for detecting intensity of the radiation emitted from said radiation source and transmitted through the object so as to obtain detection data representing radiation image information;
• driving means to be used for changing a distance between the object and said detecting means;
• and
• phase data calculating means for restoring phase information on the radiation transmitted through the object on the basis of plural sets of detection data obtained by detecting intensity of the radiation at different distances so as to obtain phase data.

A program for restoring phase information on radiations transmitted through an object on the basis of detection data obtained by emitting the radiations from a radiation source and detecting intensity of the radiation transmitted through the object, said program actuating a CPU to execute the procedures of:

• controlling said radiation source to emit each of radiations having different wavelengths with energy from 16 keV to 30 keV;
• obtaining a Laplacian of phase on the basis of plural sets of detection data obtained by detecting intensity of the radiations having different wavelengths;
• and
• obtaining phase data of the radiation by performing inverse Laplacian computation on the Laplacian of phase.

A program for restoring phase information on a radiation transmitted through an object on the basis of detection data obtained by emitting the radiation from a radiation source and detecting intensity of the radiation transmitted through the object, said program actuating a CPU to execute the procedures of:

• controlling said radiation source to emit a radiation having a predetermined wavelength with energy from 16 keV to 30 keV;
• obtaining a Laplacian of phase on the basis of plural sets of detection data obtained by detecting intensity of the radiation at different distances;
• and
• obtaining phase data of the radiation by performing inverse Laplacian computation on the Laplacian of phase.

A program for restoring phase information on a radiation transmitted through an object on the basis of detection data obtained by detecting intensity of the radiation emitted from a radiation source having a focal spot size σ in a position at a distance R from the object and transmitted through the object, said program actuating a CPU to execute the procedures of:

• obtaining plural sets of detection data respectively representing plural kinds of radiation image information on plural detection planes at different distances zi from the object by using a radiation detector for detecting intensity of applied radiation on the plural detection planes to generate a detection signal representing radiation image information in which a pixel size is not less than πσz/3R, where z is a maximum value of zi;
• and
• obtaining a Laplacian of phase on the basis of said plural sets of detection data;
• and
• obtaining phase data of the radiation by performing inverse Laplacian computation on the Laplacian of phase.

A program for restoring phase information on a radiation transmitted through an object on the basis of detection data obtained by detecting intensity of the radiation emitted from a radiation source having a focal spot size σ in a position at a distance R from the object and transmitted through the object, said program actuating a CPU to execute the procedures of:

• acquiring plural sets of first detection data obtained by detecting intensity of the radiation on plural detection planes at different distances zi from the object;
• respectively generating plural sets of second detection data by suppressing spatial frequency components larger than 3R/2πσz with respect to said plural sets of first detection data, where z is a maximum value of zi;
• obtaining a Laplacian of phase on the basis of said plural sets of second detection data;
• and
• obtaining phase data of the radiation by performing inverse Laplacian computation on the Laplacian of phase.