Imaging apparatuses and methods

Claim 2

An imaging apparatus comprising: a first image memory means (U) for storing an electronic pixel value for each pixel of a first image representation; a second image memory means (V) for storing an electronic pixel value for each pixel of a second image representation; a first filter means (44,46) for operating on each pixel value of the first image representation from the first memory means (U) with a first filter function (K) and for operating on each pixel value of the second image representation from the second memory means (V) with the first filter function (K); a first transform means (48) for transforming filtered pixel values from the first and second memory means (U,V) into a first composite image; and a first composite image memory means (42) for storing the first composite image.

Claim 3

An apparatus according to Claim 1 further comprising a first filter function altering means (C) for selectively altering the first filter function (K) in accordance with a statistical probability that the pixel to be filtered is free from noise degradation.

Claim 4

An apparatus according to Claim 2 wherein the filter function altering means (C) includes at least one look-up table (84,86) which is operatively connected with at least one of the first and second image memory means (U,V) to be addressed by the pixel value of at least one of each corresponding pair of pixels to be filtered, the look-up table (84,86) retrieving kernal matrix (K) values (A,B) of a filter function (K) in accordance with the addressing pixel value and wherein the first filter means (44,46) includes a convoling means (44,46) for convolving the first and second image memory means (U,V) pixel values with the kernal matrix (K).

Claim 5

An apparatus according to Claim 1 further comprising: a second filter means (54,56) for operating on each pixel value of the first image representation from the first memory means (U) with a second filter function (K) and for operating on each pixel value of the second image representation from the second memory means (V) with the second filter function (K); a second transform means (58) for transforming filtered pixel values from the first and second memory means (U,V) into a second composite image; and a second composite image memory means (52) for storing the second composite image.

Claim 6

An apparatus according to Claim 4 wherein the first and second image representations are radiation energy specific and the first and second composite images are irradiated material specific.

Claim 7

An apparatus according to Claim 4 or Claim 5 further comprising a filter function altering means (C,C) for selectively altering the first and second filter functions (K,K), the filter function altering means (C,C) being operatively connected with one of the first and second image memory means (U,V) for altering the first and second filter functions (K,K) in accordance with each pixel value to be filtered by the first and second filter means (44,46,54,56).

Claim 8

An imaging apparatus comprising: a radiation source (10) for producing at least higher energy and lower energy radiation; a radiation detection means (18,20) for separately detecting the higher and lower energy radiation traversing a selected region of interest of a subject and for producing digital electronic pixel values indicative of the intensity of higher and lower energy radiation received thereby; a higher energy image memory means (V) operatively connected with the detector means (20) for storing the higher energy radiation intensity indicative digital electronic pixel values for each pixel for a higher energy image representation of the region of interest; a lower energy image memory means (U) operatively connected with the detector means (18) for storing the lower energy radiation intensity indicative digital electronic pixel values for each pixel for a lower energy image representation of the region of interest; a first convolver means (44,46) for convolving a first filter function (K) pixel by pixel with the digital values of the higher energy image representation and for convolving the first filter function (K) pixel by pixel with the digital values of the lower energy image representation; a first filter function altering means (C) for correspondingly adjusting a characteristic of the first filter function (K) in accordance with the digital value of each pixel of at least one of the higher and lower energy image representations; a first transform means (48) for transforming convolved values of corresponding pixels of the higher and lower energy representations into digital gray scale values of corresponding pixels of a soft tissue specific basis image; a soft tissue image memory means (42) operatively connected with the first transform means (48) for storing the gray scale values of the soft tissue basis image; a second convolver means (54,46) for convolving a second filter function (K) with the digital values of the higher energy image representation and convolving the second filter function (K) with the digital values of the lower energy image representation; a second filter function altering means (C) for correspondingly adjusting a characteristic of the second filter function (K) in accordance with the digital value of each pixel of at least one of the higher and lower energy image representations; a second transform means (58) for transforming convolved values of corresponding pixels of the higher and lower energy image representations from the second convolver means (54,46) into digital gray scale values of corresponding pixels of a bone specific basis image; and a bone image memory means (52) operatively connected with the second transform means (58) for storing the gray scale values of the bone specific basis image.

Claim 9

An imaging apparatus comprising: a radiation source (10) for producing at least higher energy and lower energy radiation; a radiation detection means (18,20) for separately detecting the higher and lower energy radiation traversing a selected region of interest of a subject and for producing digital electronic pixel values indicative of the intensity of higher and lower energy radiation received thereby; a higher energy image memory means (V) operatively connected with the detector means (20) for storing the higher energy radiation intensity indicative digital electronic pixel values for each pixel for a higher energy image representation of the region of interest; a lower energy image memory means (U) operatively connected with the detector means (18) for storing the lower energy radiation intensity indicative digital electronic pixel values for each pixel for a lower energy image representation of the region of interest; a first convolver means (44,46) for convolving a first filter function (K) pixel by pixel with the digital values of the higher energy image representation and for convolving the first filter function (K) pixel by pixel with the digital values of the lower energy image representation; a first filter function altering means (C) for correspondingly adjusting a characteristic of the first filter function (K) in accordance with the digital value of each pixel of at least one of the higher and lower energy image representations; a first transform means (48) for transforming convolved values of corresponding pixels of the higher and lower energy representations into digital gray scale values of corresponding pixels of a soft tissue specific basis image; a soft tissue image memory means (42) operatively connected with the first transform means (48) for storing the gray scale values of the soft tissue basis image; a second convolver means (54,46) for convolving a second filter function (K) with the digital values of the higher energy image representation and convolving the second filter function (K) with the digital values of the lower energy image representation; a second filter function altering means (C) for correspondingly adjusting a characteristic of the second filter function (K) in accordance with the digital value of each pixel of at least one of the higher and lower energy image representations; a second transform means (58) for transforming convolved values of corresponding pixels of the higher and lower energy image representations from the second convolver means (54,46) into digital gray scale values of corresponding pixels of a bone specific basis image; and a bone image memory means (52) operatively connected with the second transform means (58) for storing the gray scale values of the bone specific basis image.

Claim 10

An imaging apparatus comprising: a first image memory (104) which stores a plurality of pixel values, each pixel value corresponding to a pixel of a first image representation; a filter function altering means (C,C) for selecting characteristics (A,B) of a filter function (K,K) in accordance with the pixel value of each pixel to be filtered, the filter function altering means (C,C) being operatively connected with the first image memory (104); a first filtering means (112,114) for operating on the pixel values of each selected pixel and pixels thereadjacent with the selectively altered filter function (K,K), whereby the filter function (K,K) with which each pixel is filtered varies in accordance with its pixel value.

Claim 11

An imaging apparatus comprising: a first image memory (104) which stores a plurality of pixel values, each pixel value corresponding to a pixel of a first image representation; a filter function altering means (C,C) for selecting characteristics (A,B) of a filter function (K,K) in accordance with the pixel value of each pixel to be filtered, the filter function altering means (C,C) being operatively connected with the first image memory (104); a first filtering means (112,114) for operating on the pixel values of each selected pixel and pixels thereadjacent with the selectively altered filter function (K,K), whereby the filter function (K,K) with which each pixel is filtered varies in accordance with its pixel value.

Claim 12

An apparatus according to Claim 8 further comprising: a second image memory (102) for storing pixel values of a second image representation; a second filtering means (110,116) for operating on the pixel values from the second image memory (102) for each selected pixel and pixels thereadjacent with the selectively altered filter function (K,K) whereby the filter function (K,K) with which each second image memory (102) pixel is filtered varies in accordance with the pixel value of the corresponding pixel of the first image memory (104); a first filtered image memory means (122,124) operatively connected with the first filtering means (112,114) for receiving filtered first image pixel values therefrom; a second filtered image memory means (120,126) operatively connected with the second filtering means (110,116) for receiving filtered second image pixel values therefrom; a transform means (130) operatively connected with the first and second filtered image memory means (120,122,124,126) for transforming the filtered first and second image pixel values into corresponding pixel values of a composite image representation; and a composite image memory means (134) operatively concentrated with the transform means (130) for storing the composite image pixel values.

Claim 13

An apparatus according to Claim 9 further comprising a transform altering means (132) for selectively altering the transform applied by the transform means (130), the transform altering means (130) being operatively connected with at least one of the first and second filtered image memory means (120,122,124,126) for selectively altering the transform in accordance with the pixel values thereof.

Claim 16

A method acording to Claim 11 further comprising the steps of: filtering the first and second image representations with a second filter function (K) to produce second filter function filtered first and second image representations; and transforming the second filter function filtered first and second image representations with a second transform function (G) into a second composite image.

Claim 17

A method according to Claim 12 wherein: the first and second image representations represent high and low energy specific radiograph images respectively; and the first and second transform functions (F,G) transform the filtered image representations into images representative of a first material and a second material such that the first composite image is a first material specific image and the second composite image is a second material specific image.

Claim 18

A method according to Claim 11 or Claim 12 or Claim 13 wherein: the first and second image representations are each defined by a plurality of pixels, each pixel of the first image representation having a corresponding pixel in the second image representation which represents the same subregion of an imaged region of interest, each image representation having a plurality of pixel values, each pixel value corresponding to one of the pixels, and said method further comprises the step of altering the first filter function (K) in accordance with a characteristic of each pixel value to be filtered such that the first fitler function (K) is varied in accordance with the pixel value of each pixel to be filtered.

Claim 21

A method according to Claim 15 wherein: each filter function (K) includes a matrix (K); the filter function selecting step includes selecting the values (A,B) of matrix elements; and the filtering step includes convolving pixel values of the image representation with the mnatrix (K).

Claim 22

A method according to Claim 15 or Claim 16 further comprising the steps of: repeating the five steps for a second image representation such that a second filtered image representation is generated; and transforming the first and second filtered image representations into a plurality of composite images.

Claim 23

A method according to Claim 17 wherein: the steps of generating first and second image representations include irradiating a common region of interest of a subject with radiation of first and second energy levels respectively and measuring the intensity of radiation of each of the first and second level traversing the region of interest: and the composite images include a first material basis image and a second material basis image.

Claim 26

A method according to Claim 18 wherein: the image representation generating step includes irradiating the subject with radiation of a first energy level to generate the first image representation and irradiating the subject with radiation of a second energy level to generate the second image representation; and the transform functions (F,G) are selected such that the first composite image is material specific to a first material and the second composite image is material specific to a second material.

Claim 27

A method according to Claim 19 or Claim 20 further comprising the step of altering at least one of the first filter (K) and first transform (F) functions and altering at least one of the second filter (K) and second transform (G) functions in accordance with characteristics of at least one of the first and second image representations.