EP0424912A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Region extracting method and three-dimensional display method
Assignee: Hitachi Ltd
•
Filing: 1990-10-24
•
Granted: —
•
Expires: 2010-10-24
Abstract
Abstract In order to ensure that region extraction for extracting a specified internal organ can be effected with high reliability a region expansion method is applied by using an expansion condition (equation (1)) taking the local density change into consideration and an expansion condition (equation (4)) taking the global density change into consideration in combination.
Inventors
- 👤 Hiroyuki Sekiguchi
- 👤 Koichi Sano
- 👤 Tetsuo Yokoyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 10:37
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/20
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
93 words
A region extracting method comprising the steps of: preparing (100) a multi-dimensional image data by combining two or more two-dimensional tomography image data sheets; detecting (102) at least two kinds of features representative of a local change and a global change in a pixel value by using the prepared data; calculating (102) a composite feature which is a combination of said features; performing (103) a region expansion by using said composite feature as the condition for expansion; and adding to data (A₀) prepared through said region expansion a region (A′) surrounding said data.
Claim 2
Dependent Claim
93 words
A region extracting method comprising the steps of: preparing (100) a multi-dimensional image data by combining two or more two-dimensional tomography image data sheets; detecting (102) at least two kinds of features representative of a local change and a global change in a pixel value by using the prepared data; calculating (102) a composite feature which is a combination of said features; performing (103) a region expansion by using said composite feature as the condition for expansion; and adding to data (A₀) prepared through said region expansion a region (A′) surrounding said data.
Claim 3
Dependent Claim
56 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes selecting a pixel acting as a representative point of a region of interest, and sequentially expanding the region toward a pixel adjacent to said representative pixel by using said representative pixel as a start point (f₀) of region expansion.
Claim 4
Dependent Claim
48 words
A region extracting method according to Claim 1, wherein said step of calculating a composite feature includes determining features of a region of interest, weighting (a, b) said two kinds of features in accordance with the features of said region of interest, and adding together the weighted features.
Claim 5
Dependent Claim
73 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes defining, as said global change, a difference between an average of values of pixels in the vicinity of said start point and a value of a pixel subject to region expansion, and using, as one of feature expansion conditions, the fact that the difference falls within a range defined by a predeterminedly designated set value (β).
Claim 6
Dependent Claim
68 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes defining, as said local change, a change in value of a pixel inside a region in the vicinity of a point subject to region expansion, and using, as one of region expansion conditions, the fact that said change value falls within a range defined by a predeterminedly designated set value (α).
Claim 7
Dependent Claim
45 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes looking up features of individual internal organs to automatically set coordinates of said start point and setting values (f₀) in accordance with an internal organ to be extracted.
Claim 8
Dependent Claim
42 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes performing the region expansion by changing the local and global constraint conditions in accordance with imaging conditions and features of a region to be extracted.
Claim 9
Dependent Claim
73 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes executing extraction of a region of interest a plurality of times in respect of the same image data by using at least two or more different local and global constraint conditions and calculating the number by which each pixel is extracted, and determining the ultimate range of region extraction on the basis of the calculated number.
Claim 10
Dependent Claim
50 words
A region extracting method according to Claim 1, wherein said step of performing a region expansion includes adding a region (A′) of one or more dots around the extracted region (A₀) obtained through said region expansion, and weighting said added region in accordance with the distance from the region boundary.
Claim 11
Dependent Claim
101 words
A region extracting method according to Claim 9, wherein said steps of adding dots and weighting said added region are effected by repeating a processing indicated by the following formulas when n-dimensional data is used: g₁(x₁,x₂, ..., x n ) = 1 ... when g (x₁,x₂, ..., x n ) = 1 (inside the region) ... when g₀(x₁,x₂, ..., x n ) = 0 (outside the region) where g₀ (x₁, x₂, ..., x n ) is image data obtained through region expansion and is 1 (one) for the interior of the region and 0 (zero) for the exterior of the region.
Claim 12
Dependent Claim
38 words
A region extracting method according to Claim 10, wherein said weighted region extraction data is multiplied by said multi-dimensional image data in respect of individual pixels to reflect the density of the original image on the extraction region.
Claim 13
Dependent Claim
51 words
A region extracting method comprising the steps of: applying extraction of internal organ based on region expansion to a plurality of organs to obtain region extraction data in respect of individual internal organs; and storing the region extraction data in part of three-dimensional image data or in a three-dimensional array (910).
Claim 14
Dependent Claim
51 words
A region extracting method comprising the steps of: applying extraction of internal organ based on region expansion to a plurality of organs to obtain region extraction data in respect of individual internal organs; and storing the region extraction data in part of three-dimensional image data or in a three-dimensional array (910).
Claim 15
Dependent Claim
65 words
A region extracting method according to Claim 12, wherein said step of storing the region extraction data includes storing the region extraction data for each internal organ in the form of any one of a code (912) corresponding to each internal organ, a bit string (915) containing bits corresponding to individual internal organs and the probability (916 - 919) of existence of each internal organ.
Claim 16
Dependent Claim
35 words
A three-dimensional display method comprising the steps of: extracting a specified region through region expansion; and applying a three-dimensional image preparing method based on volume rendering to said specified region to construct a three-dimensional image.
Claim 17
Dependent Claim
35 words
A three-dimensional display method comprising the steps of: extracting a specified region through region expansion; and applying a three-dimensional image preparing method based on volume rendering to said specified region to construct a three-dimensional image.
Claim 18
Dependent Claim
43 words
A three-dimensional display method according to Claim 14, wherein said step of extracting a specified region includes changing pixel values in a region to be displayed and in a region not to be displayed within an original image by using region extraction data.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.