Disparity compensation of light fields for improved efficiency in 4D transform-based encoders

Santos, Joao M.; Thomaz, Lucas A.; Assuncao, Pedro A. A.; Cruz, Luis A. da Silva; Tavora, Luis M. N.; Faria, Sergio M. M. de

http://hdl.handle.net/10400.8/13672

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Disparity compensation of light fields for improved efficiency in 4D transform-based encoders.pdf	Efficient light field en coders take advantage of the inherent 4D data structures to achieve high compression performance. This is accomplished by exploiting the redundancy of co-located pixels in different sub-aperture images (SAIs) through prediction and/or transform schemes to find a m ore compact representation of the signal. However, in image regions with higher disparity between SAIs, such scheme's performance tends to decrease, thus reducing the compression efficiency. This paper introduces a reversible pre-processing algorithm for disparity compensation that operates on the SAI domain of light field data. The proposed method contributes to improve the transform efficiency of the encoder, since the disparity-compensated data presents higher correlation between co-located image blocks. The experimental results show significant improvements in the compression performance of 4D light fields, achieving Bjontegaard delta rate gains of about 44% on average for MuLE codec using the 4D discrete cosine transform, when encoding High Density Camera Arrays (HDCA) light field images.	5.02 MB	Adobe PDF	Download

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Authors

Santos, Joao M.

Thomaz, Lucas A.

Assuncao, Pedro A. A.

Cruz, Luis A. da Silva

Tavora, Luis M. N.

Faria, Sergio M. M. de

Abstract(s)

Efficient light field en coders take advantage of the inherent 4D data structures to achieve high compression performance. This is accomplished by exploiting the redundancy of co-located pixels in different sub-aperture images (SAIs) through prediction and/or transform schemes to find a m ore compact representation of the signal. However, in image regions with higher disparity between SAIs, such scheme's performance tends to decrease, thus reducing the compression efficiency. This paper introduces a reversible pre-processing algorithm for disparity compensation that operates on the SAI domain of light field data. The proposed method contributes to improve the transform efficiency of the encoder, since the disparity-compensated data presents higher correlation between co-located image blocks. The experimental results show significant improvements in the compression performance of 4D light fields, achieving Bjontegaard delta rate gains of about 44% on average for MuLE codec using the 4D discrete cosine transform, when encoding High Density Camera Arrays (HDCA) light field images.

Description

EISBN - 978-1-7281-8068-7
Article number - 9301829; Conference date - 1 December 2020 - 4 December 2020; Conference code - 166231

Keywords

4D light field codecs disparity compensation Light field compression

URI

http://hdl.handle.net/10400.8/13672

Citation

J. M. Santos, L. A. Thomaz, P. A. A. Assuncao, L. A. da Silva Cruz, L. M. N. Tavora and S. M. M. Faria, "Disparity compensation of light fields for improved efficiency in 4D transform-based encoders," 2020 IEEE International Conference on Visual Communications and Image Processing (VCIP), Macau, China, 2020, pp. 112-115, doi: https://doi.org/10.1109/VCIP49819.2020.9301829.