Early TU decision method for fast video encoding in high efficiency video coding

Proposed is an early transform unit (TU) decision method for high efficiency video coding (HEVC) by early determination of the TU sizes based on coding tree pruning. Although the coding efficiency in HEVC can be improved by using various transform block sizes, the computational complexity increased dramatically in terms of the transform kernel size and the transform coding structure. A simple TU decision algorithm is proposed that can prune a residual quadtree in the early stages based on the number of nonzero DCT coefficients. Experimental results show that the proposed method achieves a 61 reduction in TU processing time compared to the HEVC test model 3.0 encoder with a little gain in coding performance.