Brick-based Fusion Renderer

• US 20070247459A1
• Filed: 05/24/2007
• Published: 10/25/2007
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens Corporate Research Incorporated (Siemens AG)
• Inventors: Li, Wei
• Granted Patent: US 7,961,186 B2
• Time in Patent Office: Days
• US Class Current: 345/424
• CPC Class Codes: G06T 15/08 Volume rendering
• CPC Class Codes: G06T 17/005 Tree description, e.g. octree, quadtree
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics

Abstract

A method for combining at image data sets to generate a composite image. The method divides each of the data sets into a plurality of bricks along three mutually orthogonal axes. The method includes (a) building a hierarchical structure for each one of the at least two data sets, each structure comprising higher level blocks of voxels and lower level blocks of voxels, the higher level blocks having a larger number of voxels than the lower level blocks; (b) expanding boundaries of each one of the structures into corresponding expanded hierarchical structures, such boundary expanding comprising adding additional virtual processing bricks to the initial processing bricks, such virtual processing bricks comprising semi-unbounded blocks to provide the expanded boundaries of the expanded hierarchical structures; and (c) rendering each one of the bricks in each one of the expanded hierarchical structures into a two dimension image.

Claims

1. A method for combining at least two three-dimensional image data sets to generate a composite image from the data sets, comprising:

dividing each one of the data sets into a plurality of bricks along three mutually orthogonal axes.

2. A method for combining at image data sets to generate a composite image comprising:

(a) building a hierarchical structure for each one of the at least two data sets, each structure comprising higher level blocks of voxels and lower level blocks of voxels, the higher level blocks having a larger number of voxels than the lower level blocks;

(b) expanding boundaries of each one of the structures into corresponding expanded hierarchical structures, such boundary expanding comprising adding additional virtual processing bricks to the initial processing bricks, such virtual processing bricks comprising semi-unbounded blocks to provide the expanded boundaries of the expanded hierarchical structures; and

(c) rendering each one of the bricks in each one of the expanded hierarchical structures into a two dimension image.

3. The method recited in claim 2 wherein the rendering comprises:

(i) processing the bricks each one of the expanded hierarchical structures in order of relative visibility, such visibility order being related to distance from a viewing camera including setting flags for invisible ones of the initial processing bricks and for the virtual processing bricks with visible bricks remaining un-flagged and wherein at any time a current brick is being rendered, cut planes defining the boundary the current brick being inserted and wherein the cut planes are removed when the current brick is no longer being rendered;

(ii) dividing each of the expanded hierarchical structures having therein the current un-flagged brick into stacks of parallel slices along the cut planes with flagged bricks being excluded from the parallel slices and sorting the parallel slices by the visibility order;

(iii) choosing a next slice in the sorted parallel slices, the next slice belonging to a currently rendered one of the bricks;

(iv) finding all blocks in each of the currently bricks intersecting a plane of the next slice chosen in the (iii);

(v) fetching voxels from the founds blocks;

(vi) rendering the fetched voxels into the two dimensional image;

(vi) repeating (iii) through (v) until all of the sorted parallel slices are rendered; and

(vii) resetting the current brick.

4. The method recited in claim 3 including repeating (i) through (vii) until all brick combinations are rendered.

5. The method recited in claim 4 wherein the parallel slices are chosen independently for each of the expanded hierarchical structures to render interleaved slices.

6. The method recited in claim 3 wherein the parallel slices are of the expanded hierarchical structures are chosen to share a common set of the parallel slices to generate fused slices;

the invisible flags being passed to the rendering function, so that fetching from an invisible brick is avoid and 0 is assigned as the value of voxel sample.

7. The method recited in claim 4 wherein the parallel slices are of the expanded hierarchical structures are chosen to share a common set of the parallel slices to generate fused slices;

the invisible flags being passed to the rendering function, so that fetching from an invisible brick is avoid and 0 is assigned as the value of voxel sample.