Method and apparatus for minimizing blurring and generating a high resolution image in a radiation imaging system

Claim 3

The method according to claim 1 wherein the combined frequency response of the filter is given by: ##EQU5## wherein: H(v r )=combined frequency response H inv (v r )=inverse filter frequency response H reg (v r )=regulation frequency response ##EQU6## v x , v y =spatial frequencies in x and y directions α=transition frequency between inversion and regularization portions.

Claim 4

The method according to claim 2 further comprising selecting a regularization function of the filter as an n th order polynomial wherein: H reg (α)=H inv (α) H inv =inverse filter frequency response H reg =regularization frequency response α=transition frequency between inverse filter frequency response portion and noise regularization frequency response portion.

Claim 5

The method according to claim 2 further comprising selecting a regularization function of the filter as an n th order polynomial wherein: ##EQU7## H reg =regularization frequency response H inv =inverse filter frequency response ##EQU8## v x , v y =spatial frequencies in x and y directions α=transition frequency between inverse filter frequency response portion and noise regularization frequency response portion.

Claim 6

The method according to claim 1 wherein image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero response at the oversampled Nyquist frequency wherein: H reg (v NYQUIST )=0 where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency.

Claim 7

The method according to claim 1 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero slope at the Nyquist frequency wherein: ##EQU9## where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency ##EQU10## v x , v y =spatial frequency in x and y directions.

Claim 8

The method according to claim 1 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and, a frequency α at the transition between the inverse frequency response portion and the noise regularization frequency response portion, and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having: a) continuity at α; b) a continuous slope at α; c) zero response at the oversampled Nyquist frequency; and d) zero slope at the oversampled Nyquist frequency.

Claim 9

The method according to claim 2 wherein image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero response at the oversampled Nyquist frequency wherein: H reg (v NYQUIST )=0 where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency.

Claim 10

The method according to claim 2 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero slope at the Nyquist frequency wherein: ##EQU11## where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency ##EQU12## v x , v y =spatial frequency in x and y directions.

Claim 11

The method according to claim 2 wherein the image data s signals produced by the radiation imaging system have an oversampled Nyquist frequency and, a frequency α at the transition between the inverse frequency response portion and the noise regularization n frequency response portion, and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having: a) continuity at α; b) a continuous slope at α; c) zero response at the oversampled Nyquist frequency; and d) zero slope at the oversampled Nyquist frequency.

Claim 14

The method according to claim 11 wherein the combined frequency response of the filter is given by: ##EQU13## wherein: H(v r )=combined frequency response H inv (v r )=inverse filter frequency response H reg (v r )=regulation frequency response ##EQU14## v x , v y =spatial frequencies in x and y directions α=transition frequency between inversion and regularization portions.

Claim 15

The method according to claim 12 further comprising selecting a regularization function of the filter as an n th order polynomial wherein: H reg (α)=H inv (α) H inv =inverse filter frequency response H reg =regularization frequency response α=transition frequency between inverse filter frequency response portion and noise regularization frequency response portion.

Claim 16

The method according to claim 12 further comprising selecting a regularization function of the filter as an n th order polynomial wherein: ##EQU15## H reg =regularization frequency response H inv =inverse filter frequency response ##EQU16## v x , v y =spatial frequencies in x and y directions α=transition frequency between inverse filter frequency response portion and noise regularization frequency response portion.

Claim 17

The method according to claim 11 wherein image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero response at the oversampled Nyquist frequency wherein: H reg (v NYQUIST )=0 where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency.

Claim 18

The method according to claim 11 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero slope at the Nyquist frequency wherein: ##EQU17## where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency ##EQU18## vx, v y =spatial frequency in x and y directions.

Claim 19

The method according to claim 11 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and, a frequency α at the transition between the inverse frequency response portion and the noise regularization frequency response portion, and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having: a) continuity at α; b) a continuous slope at α; c) zero response at the oversampled Nyquist frequency; and d) zero slope at the oversampled Nyquist frequency.

Claim 20

The method according to claim 12 wherein image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero response at the oversampled Nyquist frequency wherein: H reg (v NYQUIST )=0 where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency.

Claim 21

The method according to claim 12 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having zero slope at the Nyquist frequency wherein: ##EQU19## where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency ##EQU20## v x , v y =spatial frequency in x and y directions.

Claim 22

The method according to claim 12 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and, a frequency α at the transition between the inverse frequency response portion and the noise regularization frequency response portion, and further comprising selecting the noise regularization frequency response portion of the filter as an n th order polynomial having: a) continuity at α; b) a continuous slope at α; c) zero response at the oversampled Nyquist frequency; and d) zero slope at the oversampled Nyquist frequency.

Claim 23

The method of claim 11 wherein the step of sequentially positioning said array of photosensor pixels further comprises the step of displacing said photosensor pixel array in a selected sequence so that said array is respectively disposed at each of four imaging positions during said imaging cycle.

Claim 24

The method of claim 21 wherein the step of displacing said array further comprises sequentially translating said array along a first axis and a second axis, said first and second axes being orthogonal.

Claim 25

The method of claim 22 wherein the distance along said first and second axes between respective ones of said four imaging positions correspond to one-half of photosensor pixel pitch.

Claim 26

The method of claim 23 further comprising the step of driving a display and analysis module to present said high resolution data.

Claim 27

A radiation imaging system comprising: a photosensor pixel array, said array adapted to generate an image data signal being sequentially disposed in selected ones of a plurality of sequential imaging positions pursuant to a predetermined imaging cycle, each of said sequential imaging positions being selected so as to oversample the imaged area; and an image processor coupled to said photosensor pixel array so as to receive the respective image data signals generated, said image processor being adapted to store said respective image data signals generated during an imaging cycle in each of said respective sequential imaging positions as an unfiltered data set, said image processor further comprising a finite impulse response deblurring filter adapted to selectively filter said data set to generate a non-aliased fine resolution data set having spatial resolution greater than the imaging system Nyquist frequency determined by pixel pitch of said photosensor, array, said deblurring filter having a combined frequency response comprising an inverse filter frequency response portion and a noise regularization frequency response portion wherein the noise regularization decreases the frequency response of the filter as the frequency of the signal increases.

Claim 28

A radiation imaging system comprising: a photosensor pixel array, said array adapted to generate an image data signal being sequentially disposed in selected ones of a plurality of sequential imaging positions pursuant to a predetermined imaging cycle, each of said sequential imaging positions being selected so as to oversample the imaged area; and an image processor coupled to said photosensor pixel array so as to receive the respective image data signals generated, said image processor being adapted to store said respective image data signals generated during an imaging cycle in each of said respective sequential imaging positions as an unfiltered data set, said image processor further comprising a finite impulse response deblurring filter adapted to selectively filter said data set to generate a non-aliased fine resolution data set having spatial resolution greater than the imaging system Nyquist frequency determined by pixel pitch of said photosensor, array, said deblurring filter having a combined frequency response comprising an inverse filter frequency response portion and a noise regularization frequency response portion wherein the noise regularization decreases the frequency response of the filter as the frequency of the signal increases.

Claim 29

An imaging system according to claim 25 wherein the combined frequency response of the filter is given by: ##EQU21## wherein: H(v r )=combined frequency response H inv (v r )=inverse filter frequency response H reg (v r )=regulation frequency response ##EQU22## v x , v y =spatial frequencies in x and y directions α=transition frequency between inversion and regulariztion portions.

Claim 30

An imaging system according to claim 26 wherein the regularization function of the filter in an n th order polynomial wherein: H reg (α)=H inv (α) H inv =inverse filter frequency response H reg =regularization frequency response α=transition frequency between inverse filter frequency response portion and noise regularization frequency response portion.

Claim 31

In imagine system according to claim 26 wherein the regularization function of the filter is an nt order polynomial wherein: ##EQU23## H reg =regularization frequency response H inv =inverse filter frequency response ##EQU24## v x , v y =spatial frequencies in x and y directions α=transition frequency between inverse filter frequency response portion and noise regularization frequency response portion.

Claim 32

An imaging system according to claim 25 wherein the noise regularization frequency response portion of the filter is an n th order polynomial having zero response at the oversampled Nyquist frequency wherein: H reg (v NYOUIST )=0 where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency.

Claim 33

An imaging system according to claim 25 wherein he image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and wherein the noise regularization frequency response portion of the filter is an n th order polynomial having zero slope at the Nyquist frequency wherein: ##EQU25## where: H reg (v NYQUIST )=noise regularization frequency response at Nquist frequency ##EQU26## v x , v y =spatial frequency in x and y directions.

Claim 34

An imaging system according to claim 25 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and, a frequency α at the transition between the inverse frequency response portion and the noise regularization frequency response portion of the combined frequency response of the filter and the noise regularization frequency response portion of the filter is an n th order polynomial having: a) continuity at α; b) a continuous slope at α; c) zero response at the oversampled Nyquist frequency; and d) zero slope at the oversampled Nyquist frequency.

Claim 35

An imaging system according to claim 26 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and wherein the noise regularization frequency response portion of the filter as an n th order polynomial having zero response at the oversampled Nyquist frequency wherein: H reg (v NYQUIST )=0 where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency.

Claim 36

An imaging system according to claim 26 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and wherein the noise regularization frequency response portion of the filter is an n th order polynomial having zero slope at the Nyquist frequency wherein: ##EQU27## where: H reg (v NYQUIST )=noise regularization frequency response at Nyquist frequency ##EQU28## v x , v y =spatial frequency in x and y directions.

Claim 37

An imaging system according to claim 26 wherein the image data signals produced by the radiation imaging system have an oversampled Nyquist frequency and, a frequency α at the transition between the inverse frequency response portion and the noise regularization frequency response portion, and wherein the noise regularization frequency response portion of the filter is an n th order polynomial having: a) continuity at α; b) a continuous slope at α; c) zero response at the oversampled Nyquist frequency; and d) zero slope at the oversampled Nyquist frequency.