Volume rendering based on sorted volumetric data.
OBJECTIVE
To describe a spatial data structure called sorted volumetric data structure which speeds up the volume rendering and will not affect image quality.


METHODS
Before volume rendering we transfer each slice of volume into an array indexed by the value of voxels, element in which stores the position of each voxel. According to the opacity transfer function, we can affirm the value ranges of voxels that are non-transparent. Therefore we translate, resample and composite only the voxels in the value ranges. By marching through the sorted arrays, we locate the non-transparent voxels rapidly and skip all voxels that are transparent. The sorted data structures need not recompute whenever the opacity transfer function changes and are not restricted on the opacity transfer function.


RESULTS
The method presented in this paper has been implemented in a standard personal computer. The rendering time for CT head volume data is less than 1 s that is satisfied with the diagnostic purpose.


CONCLUSIONS
The concept of proposed algorithm is simple, easy to realize and it is not recomputed whenever the opacity transfer function changes. By using the sorted volumetric data structure, we speed up the volume rendering without affecting image quality.
Institute of Biomedical Engineering, University of Science & Technology of China, Hefi Anhui.
Bin
B
Zhuge
Huan-qing
HQ
Feng
He-qin
HQ
Zhou
D000465:Algorithms; D001842:Bone and Bones / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006257:Head / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D012867:Skin / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed