Low complexity transform competition for HEVC

The use of multiple transforms in video coding can lead to substantial bit-rate savings. However, these savings come at the expense of increased coding complexity and storage requirements, which challenge the usability of this approach. In this paper, a systematic procedure is proposed to design low complexity systems making use of transform competition. Multiple trade-offs accommodating the complexity are unveiled and it is demonstrated that they can keep a certain level of performance. Compared to the HEVC standard, some of them provide bit-rate savings around 2% with a 50% increase in the encoding time, using less than 4 kB of extra ROM and no added decoding complexity.