Visualization using histogram based transfer functions for 3D cardiac volume data set

A key process in the application of volume rendering is to design an appropriate transfer function according to the needs of visualization. In this paper, the design of 1D histogram based transfer function is firstly introduced to make full use of the gray levels of 3D cardiac volume data. Opacity modulation based on statistics of the specific gray level is then presented to observe the interior subtle cardiac tissues clearly. Furthermore, 2D histogram based transfer function using gray level and gradient magnitude is also proposed to enhance boundaries of cardiac tissues. Experimental results validate that our proposed transfer functions are effective and efficient in volume rendering for cardiac volume data set.