A new two-dimensional transfer functions for volume rendering

Most direct volume rendering produced today still employ one-dimensional (1D) transfer function. The 1D transfer function is very convenient, but their capability for extracting specific material boundaries is not entirely satisfactory. The two-dimensional (2D) transfer functions are known as a very effective way to extract specific material boundaries and convey subtle surface properties, though they are not convenient enough for operators. That makes the 2D transfer functions not been wildly used yet. This paper demonstrates a new 2D transfer functions which based on 1D transfer function and combined with methods of traditional 2D transfer functions. That means this new 2D transfer functions are convenient as the 1D function and capable as the traditional 2D transfer functions.