Volume Visualization - Abhijeet Ghosh


HDR Display CT head
  Volume Rendering for High Dynamic Range Displays
Dynamic range restrictions of conventional displays limit the amount of detail that can be represented in volume rendering applications. However, high dynamic range displays with contrast ratios larger than 50,000:1 have recently been developed. We explore how these increased capabilities can be exploited for common volume
rendering algorithms such as direct volume rendering and maximum projection rendering. In particular, we discuss distribution of intensities across the range of the display contrast and a mapping of the transfer function to a perceptually linear space over the range of intensities that the display can produce. This allows us to reserve
several just noticeable difference steps of intensities for spatial context apart from clearly depicting the main regions of interest. We also propose generating automatic transfer functions for order independent operators through histogram-equalization of data in perceptually linear space.


 
Hardware Assisted Multichannel Volume Rendering

We explore real time volume rendering of multichannel data for volumes with color and multi-modal information. We demonstrate volume rendering of the Visible Human Male color dataset and photo-realistic rendering of voxelized terrains, and achieve high quality visualizations. We render multi-modal volumes utilizing hardware programmability for accumulation level mixing, and use CT and MRI information as examples. We also use multi-board parallel/distributed rendering schemes for large datasets and investigate scalability issues. We employ the Volume-Pro 1000 for real time multichannel volume rendering. Our approach, however, is not hardware-specific and can use commodity texture hardware instead.   

 mutichannel volumerendering
 
object partitioned rendering
 Master's Project - Parallel Volume Rendering using Multiple VolumePro Boards

We implement distributed volume rendering using multiple VolumePro 500 boards over a high-speed Myrinet interconnect and parallel rendering using multiple VolumePro 1000 boards on a single PC.