Authors: Cristian Perra; Daniele D. Giusto
Addresses: Department of Electrical and Electronic Engineering, University of Cagliari, Italy ' Department of Electrical and Electronic Engineering, University of Cagliari, Italy
Abstract: Recent advances in light field technologies is fostering the research and development of novel imaging applications. Such applications perform processing of the light field information to create new visual effects such as, for example, refocusing, perspective change, colour adjustment. Light field imaging is very data intensive compared with usual digital photographic imaging, and novel compression algorithms are needed for addressing the problem of light field storage and transmission. Raw digital light field images exhibit low spatial correlation if compared to regular images and hence the performance in terms of rate-distortion of current state-of-the-art image encoders can be superseded by devising novel image compression architectures. In this paper, an architecture for lossy compression of unfocused light field images is proposed. Raw light fields are preprocessed by demosaicing, devignetting and slicing of the raw lenslet array image. The slices are then compressed with the JPEG 2000 image coding standard. The performance of the proposed method is compared against direct application of JPEG 2000 compression on the 4D light field. The experimental analysis has been conducted under a set of different compression ratios and the obtained results show that the proposed method outperforms direct application of the reference architecture.
Keywords: light field compression; raw light field; plenoptic image; sliced lenslet array; sub-aperture image; JPEG2000 compression; wavelet compression; light field interpolation; objective quality evaluation; peak signal-to-noise ratio; PSNR; structural similarity index; SSIM.
International Journal of Internet Technology and Secured Transactions, 2018 Vol.8 No.1, pp.48 - 61
Received: 28 Feb 2017
Accepted: 12 Jul 2017
Published online: 23 May 2018 *