Abstract: A method generates a histogram of a volume data set in a rendering pipeline. The volume data set includes a plurality of samples stored in a memory. Each sample is partitioned in parallel into a plurality of field according to a plurality of format registers, there is one format register for each field. Entries of a plurality of tables are indexed in parallel with the plurality of fields, there is one entry indexed in each table by each field. The indexed entries are incremented to accumulate a histogram of the fields of the samples of the volume data set.

Abstract: A method maps samples in a rendering pipelines. The samples are stored in a sample memory. Each sample has a plurality of fields. A descriptor is stored for each field in a field format register. Each sample is read from the memory into a mapping unit. The fields are extracted from each sample according to the corresponding descriptor, and forwarded in parallel to the rendering pipeline.

Abstract: A volume rendering pipeline includes a plurality of processing stages such as a gradient estimation stage, an interpolation stage, a classification stage, an illumination stage, and a compositing stage. The stages are connected to each other by multiplexers. A first multiplexer connects an output of a first stage to an input of a second stage. A second multiplexer connects an output of the second stage to an input of the first stage. A third multiplexer has inputs connected to the output of the first stage and the output of the second stage, the first, second, and third multiplexers are responsive to a select signal to configure the stages of the rendering pipeline for processing the volume data set.

Abstract: A low-cost, real-time volume rendering system including a three-dimensional cursor for interactively identifying and marking positions within a three-dimensional volume data set during display is disclosed. The cursor appearance is configurable such that it may appear as cross hairs, cross planes, or some combination thereof, with each cursor dimension being selectively enabled. Each cursor dimension is configurable in terms of color and level of opacity. The shape of the edges and the appearance of the intersection of the dimensions is configurable, and the colors of the individual cursor components may alternately blend or obscure the colors of the objects behind them. The cursor is realized through use of a comparison circuit operating in conjunction with a parallel pipeline processor optimized for volume rendering using a ray-casting technique.