Generation of a display data set with volume rendering

Patent metadata

Field	Value
Publication number	US-9646409-B2
Application number	US-201514972283-A
Country	US
Kind code	B2
Filing date	Dec 17, 2015
Priority date	Dec 17, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A display data set depicting a three-dimensional source data set of display parameters is generated through volume rendering. Integration distance is subdivided based on a fixed predetermined target sampling distance independent of a desired sampling distance. The number of subsections minus one correspond to integrations over different subsections with front and back values of the display parameter as a target sampling distance opacity. A contribution of the volume-rendering integral and a target sampling distance color coefficient are based on the target sampling distance opacity. Target sampling distance opacities and target sampling distance color coefficients are determined based on pre-integration tables for contributions of the volume-rendering integral. Third opacities are calculated and converted to the desired sampling distance from target sampling distance opacities and the ratio of desired sampling distance to target sampling distance. Third color coefficients are calculated, and the volume-rendering integral is determined from the contributions.

First claim

I claim:

1. A method for generating a display data set for depicting a three dimensional source data set of at least one display parameter through volume rendering, wherein a volume-rendering integral with an integrand and with an extinction function that assigns one extinction value for each distance to a value of the display parameter, and a color function that assigns at least one chromaticity for each path to the value of the display parameter is evaluated to determine the display data set and wherein the volume-rendering integral is broken down into contributions from third opacities as integrals dependent upon the extinction function and third color coefficients as integrals dependent upon the color function and the extinction function, wherein the color function and the extinction function are described by a front value and a back value of the display parameter and a desired sampling distance describing a interval used for integration, the method comprising, at least the following acts for the evaluation of the volume-rendering integral:
subdividing a integration distance into at least two subsections based on at least one subdivision parameter, wherein the integration distance is based on a fixed predetermined target sampling distance independent of the desired sampling distance;
providing a subsection number corresponding to a number of subsections of pre-integration tables, wherein the subsection number minus one corresponds to integrations over different subsections wherein the front value and the back value of the display parameter are assigned a target sampling distance opacity, wherein a contribution of the volume-rendering integral and at least one target sampling distance color coefficient are based on the target sampling distance opacity;
determining target sampling distance opacities and target sampling distance color coefficients based on pre-integration tables for each contribution of a plurality of contributions of the volume-rendering integral; calculating third opacities converted to the desired sampling distance from target sampling distance opacities and the ratio of desired sampling distance to target sampling distance;
calculating third color coefficients from target sampling distance opacities, target sampling distance color coefficients, and the ratio of desired sampling distance to target sampling distance; and
determining the volume-rendering integral from the contributions.

2. The method of claim 1 , further comprising:
calculating third opacities as 1−α′(0,1)=(1−α(0,1)) d′/d; and
calculating the third color coefficients as

C
′

⁡

(

0
,
1

)

=

∑

i
=
0

n

⁢

⁢

C
⁡

(

λ
i

,

λ

i
+
1

)

⁢

1
-

T
⁡

(

λ
i

,

λ

i
+
1

)

x

1
-

T
⁡

(

λ
i

,

λ

i
+
1

)

⁢

∏

j
=
0

i
-
1

⁢

⁢

T
⁡

(

λ
j

,

λ

j
+
1

)

x

,

wherein
α′(0,1) designates the third opacity over the entire integration distance of 0 to 1,
α(0,1) designates the opacity also optionally available as the target sampling distance opacity for the entire integration distance of 0 to 1 for the target sampling distance,
C′(0,1) designates the third color coefficients over the entire integration distance of 0 to 1, λ i designates numbers ordered as subdivision parameters satisfying 0≦λ i ≦λ 2 ≦ . . . ≦λ n ≦1 with the convention that λ

Assignees

• Schneider Robert
• Siemens Healthcare Gmbh

Inventors

• Schneider Robert

Classifications

• G06T17/20

  Finite element generation, e.g. wire-frame surface description, {tesselation} · CPC title

• G06T15/20

  Perspective computation · CPC title

• G06T17/00

  Three-dimensional [3D] modelling for computer graphics · CPC title

• G06T15/00

  Three-dimensional [3D] image rendering · CPC title

• G06T15/08 Primary

  Volume rendering · CPC title