Resample and composite engine for real-time volume rendering
AssigneeRutgers, The State University of NJ
InventorsHarvey Ray, Deborah Silver
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Abstract
The present invention is a digital electronic system for rendering a volume image in real time. The system accelerators the processing of voxels through early ray termination and space leaping techniques in the projection guided ray casting of the voxels. Predictable and regular voxel access from high-speed internal memory further accelerates the volume rendering. Through the acceleration techniques and devices of the present invention real-time rendering of parallel and perspective views, including those for stereoscopic viewing, are achieved.
Claims19
A digital electronic system for real-time volume rendering of a 3D volume dataset comprising:
- a data-processing accelerator for reducing a number of voxels for rendering an image in real-time by selecting image-forming voxels that are non-transparent and non-occluded from a projection and by rejecting non-image-forming voxels that are transparent or occluded from the projection, wherein the voxels are a volume dataset of the image to be rendered contained in memory external to the system;
- a control unit for forward projecting the 3D volume dataset at regularly spaced voxel positions to determine number of rays to be casted wherein said 3D volume dataset is divided into a plurality of voxel access blocks having a cubic array of voxel;
- a processor for ray casting the rays of the image-forming voxels in a front-to-back order to form 2D representation of image planes;
- a hardware engine for accelerating the real-time volume rendering by having the image-forming voxels available for processing without having to refetch a substantial number of the voxels from the external memory;
- wherein the real-time image is rendered from the image-planes formed from the selected voxels.
A method for rendering a real-time image comprising:
- retrieving a volume dataset from external memory;
- subdividing the volume dataset into a plurality of voxel access blocks, wherein said voxel access blocks are a cubic array of voxels;
- storing the voxel access blocks in high-speed internal memory;
- forward projecting the voxels located at the corners of the block to determine number of rays to be casted, wherein said corner voxels correspond to a position of said block;
- ray casting the rays in a front-to-back order to form a two-dimensional representation therefrom;
- reducing a number of the voxels for rendering an image in real-time by selecting non-transparent voxels and non-occluded voxels and by rejecting transparent voxels or occluded voxels wherein the voxels are the volume dataset of the image to be rendered contained in said external memory;
- processing the selected voxels to form pixels in a plurality of processors having interleaved memories for processing and distributing the voxels thereamong without having to refetch the voxels from the external memory;
- and
- rendering a real-time image therefrom.
A method for rendering a real-time image comprising:
- retrieving a volume dataset from external memory;
- forward projecting the volume dataset at regularly spaced voxel positions to compute number of rays/pixels to be casted, wherein the dataset is divided into plurality of voxel access blocks having cubic array of voxels;
- ray casting the rays/pixels in front-to-back order visiting all voxel access blocks except for transparent or occluded blocks without having to refetch the voxels from the external memory to form a 2D representation of image planes, wherein said image planes is a calculation of color, opacity and position of the rays/pixels.
Dependencies are inferred from the claim text.