A 4D DCT-Based Lenslet Light Field Codec

Light fields aim to represent visual information in 3D space. They are 4D structures that contain the images of a given scene from a sampled 2D range of viewpoints. When acquired using a lenslet camera, in addition to the ordinary intra-view redundancy, these views have a great deal of inter-view redundancy. In this work we propose a light field codec that fully exploits the 4D redundancy of light fields by using a 4D transform and hexadeca-trees. It initially divides the light field into 4D blocks and computes a 4D Discrete Cosine Transform of each one. Then the transform coefficients of the 4D block are grouped using hexadeca-trees on a bitplane-by-bitplane basis, and the generated stream is encoded using an adaptive arithmetic coder. The proposed codec has been employed to encode the JPEG Pleno lenslet light fields. The rate-distortion results have been assessed using test conditions comparable to the ones presented at the ICIP 2017 Light Field Coding Grand Challenge. The proposed codec, despite being conceptually simple, achieves competitive rate-distortion performance.