Standard compliant light field lenslet image coding model using enhanced screen content coding framework

Abstract

With the recent advances in high computing capabilities and reliable delivery networks, it is realistic to expect emerging immersive media applications such as virtual reality (VR) and 360-deg video. ISO/IEC Motion Picture Experts Group (MPEG) has launched an MPEG-I project that focuses on not just the current but also the next-generation immersive media applications. Light field (LF) is one of the candidates under consideration by MPEG-I. A LF lenslet image contains plentiful repeating patterns since each microlens captures the same scene. On the other hand, intrablock copy (IBC) in screen content coding (SCC) increases the coding efficiency of screen content (SC) by finding the repeating patterns. SCC can be an efficient encoder for LF image compression. However, SCC is not optimized for compressing lenslet images. Therefore, we propose an efficient lenslet image coding (LIC) model using SCC to encode lenslet images based on the lenslet image characteristics. Experimental results show that our LIC model further improves the coding efficiency of SCC on lenslet images by 3.72% on average and up to 7.77% in bitrate reduction. For fast approach, LIC is faster than SCC by 44.12%. With our proposed LIC model, the encoded bitstreams are compliant with the SCC standard with an even faster decoding time.