Adaptive Content Frame Skipping for Wyner–Ziv-Based Light Field Image Compression

Abstract

Light field (LF) imaging introduces attractive possibilities for digital imaging, such as digital focusing, post-capture changing of the focal plane or view point, and scene depth estimation, by capturing both spatial and angular information of incident light rays. However, LF image compression is still a great challenge, not only due to light field imagery requiring a large amount of storage space and a large transmission bandwidth, but also due to the complexity requirements of various applications. In this paper, we propose a novel LF adaptive content frame skipping compression solution by following a Wyner–Ziv (WZ) coding approach. In the proposed coding approach, the LF image is firstly converted into a four-dimensional LF (4D-LF) data format. To achieve good compression performance, we select an efficient scanning mechanism to generate a 4D-LF pseudo-sequence by analyzing the content of the LF image with different scanning methods. In addition, to further explore the high frame correlation of the 4D-LF pseudo-sequence, we introduce an adaptive frame skipping algorithm followed by decision tree techniques based on the LF characteristics, e.g., the depth of field and angular information. The experimental results show that the proposed WZ-LF coding solution achieves outstanding rate distortion (RD) performance while having less computational complexity. Notably, a bit rate saving of 53% is achieved compared to the standard high-efficiency video coding (HEVC) Intra codec.

Improved Deep Distributed Light Field Coding

“…The approach can be adapted for light field structures by substituting one angular dimension in place of temporal dimension [12]. PhiCong et al [14] utilize an adaptive strategy to skip WZ decoding process if the synthesized view at the decoder is estimated to have a minimum quality to avoid transmitting bits for that particular view. In order to use existing DVC tools, in [14] the LF views are first downsampled to QCIF resolution and then converted to a pseudo video sequence by utilizing a so-called Hybrid scanning order.…”

“…PhiCong et al [14] utilize an adaptive strategy to skip WZ decoding process if the synthesized view at the decoder is estimated to have a minimum quality to avoid transmitting bits for that particular view. In order to use existing DVC tools, in [14] the LF views are first downsampled to QCIF resolution and then converted to a pseudo video sequence by utilizing a so-called Hybrid scanning order. Mukati et al [12] propose to use a view synthesis-based approach to synthesize light field views at the decoder utilizing only four key views picked from the four corners of the LF in order to reduce the encoding complexity radically.…”