Image space-based particle generation modeling
View Patent ↗Volume rendering is performed by a method, comprising: obtaining an original volume data, transforming the original volume data based on a distance from a viewpoint to the original volume data, to generate transformed volume data, generating particles from the transformed volume data, and projecting the particles on an image plane to obtain a 2D image corresponding to the original volume data.
1. A method comprising:
obtaining original volume data, wherein the original volume data comprises a plurality of voxels;
transforming each voxel of the plurality of voxels of the original volume data to generate a transformed volume data using:
(
x
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wherein:
(x,y,z) represent the coordinates of each voxel of the plurality of voxels of the original volume data,
(x′, y′, z′) represent the coordinates of each voxel of a second plurality of voxels of the transformed volume data,
d o represents a first distance from a viewpoint to an image plane, and
z o represents a second distance from the viewpoint to a center of the original volume data;
generating particles from the transformed volume data to produce generated particles; and
projecting the particles on the image plane to obtain a 2D image corresponding to the original volume data.
2. The method of claim 1 , wherein:
the second distance is from the viewpoint to a cross-sectional plane of the original volume data; and
the cross-sectional plane is parallel to the image plane.
3. The method of claim 2 , wherein transforming is performed such that a first length between a surface face of the original volume data furthest from the viewpoint and a surface face of the original volume data closest to the viewpoint when the original volume data is projected on to the image plane is equal to a second length of the transformed volume data along a gaze direction of the viewpoint.
4. The method of claim 1 , wherein generating particles comprises generating a particle for each voxel of the plurality of voxels.
5. The method of claim 4 , wherein:
the original volume data includes an opacity for each voxel; and
generating particles further comprises generating a particle for each voxel with a probability corresponding to the opacity of each voxel, wherein the probability corresponds to: −log(1−the opacity of each voxel).
6. The method of claim 5 , wherein each generated particle includes color information.
7. The method of claim 4 , wherein:
the 2D image includes a plurality of pixels; and
a shape of each particle of the particles projected on the image plane is identical to a shape of each pixel of the 2D image.
8. The method of claim 4 , wherein a size of each particle projected on the image plane is identical to a size of each pixel in the 2D image.
9. The method of claim 1 , wherein a normal vector of the image plane is parallel to a direction of the projection of the particles.
10. The method of claim 9 , wherein projecting the particles on the image plane comprises projecting particles that are nearest the image plane.
11. The method of claim 1 , further comprising:
generating a plurality of the 2D images corresponding to the original volume data; and
averaging the plurality of the 2D images to generate an ensemble 2D image.
12. An apparatus comprising:
a processor or programmable circuitry; and
one or more computer readable storage media collectively including instructions that, when executed by the processor or the programmable circuitry, cause the processor or the programmable circuitry to:
obtain original volume data, wherein the original volume data comprises a plurality of voxels;
transform each voxel of the plurality of voxels of the original volume data to generate a transformed volume data using:
(
x
′
,
y
′
,
z
′
)
=
(
do
z
0
0
0
do
z
0
0
0
do
zo
)
(
x
,
y
,
z
)
,
wherein:
(x,y,z) represent the coordinates of each voxel of the plurality of voxels of the original volume data,
(x′, y′, z′) represent the coordinates of each voxel of a second plurality of voxels of the transformed volume data,
d o represents a first distance from a viewpoint to an image plane, and
z o represents a second distance from the viewpoint to a center of the original volume data;
generate particles from the transformed volume data to produce generated particles; and
project the particles on the image plane to obtain a 2D image corresponding to the original volume data.
13. The apparatus of claim 12 , wherein:
the second distance is from the viewpoint to a cross-sectional plane of the original volume data; and
the cross-sectional plane is parallel to the image plane.
14. The apparatus of claim 13 , wherein transforming is performed such that a first length between a surface face of the original volume data furthest from the viewpoint and a surface face of the original volume data closest to the viewpoint when the original volume data is projected on to the image plane is equal to a second length of the transformed volume data along a gaze direction of the viewpoint.
15. The apparatus of claim 12 , wherein the instructions to generate particles comprise instructions to generate a particle for each voxel of the plurality of voxels.
16. A computer program product having instructions embodied on a computer-readable storage medium or programmable circuitry, the instructions executable by a processor or the programmable circuitry, respectively, to cause the processor or the programmable circuitry to perform operations comprising:
obtain original volume data, wherein the original volume data comprises a plurality of voxels;
transform each voxel of the plurality of voxels of the original volume data to generate a transformed volume data using:
(
x
′
,
y
′
,
z
′
)
=
(
do
z
0
0
0
do
z
0
0
0
do
zo
)
(
x
,
y
,
z
)
,
wherein:
(x,y,z) represent the coordinates of each voxel of the plurality of voxels of the original volume data,
(x′, y′, z′) represent the coordinates of each voxel of a second plurality of voxels of the transformed volume data,
d o represents a first distance from a viewpoint to an image plane, and
z o represents a second distance from the viewpoint to a center of the original volume data;
generate particles from the transformed volume data to produce generated particles; and
project the particles on the image plane to obtain a 2D image corresponding to the original volume data.
17. The computer program product of claim 16 , wherein:
the second distance is from the viewpoint to a cross-sectional plane of the original volume data; and
the cross-sectional plane is parallel to the image plane.
18. The computer program product of claim 17 , wherein the processor or the programmable circuitry performs transforming such that a first length between a surface face of the original volume data furthest from the viewpoint and a surface face of the original volume data closest to the viewpoint when the original volume data is projected on to the image plane is equal to a second length of the transformed volume data along a gaze direction of the viewpoint.
19. The computer program product of claim 16 , wherein the instructions to generate particles comprise instructions to generate a particle for each voxel of the plurality of voxels.