Ultra Low-Complexity 4-D IIR Hyperfan Filter for Light Field Denoising

• Published in: Moratuwa Engineering Research Conference pp. 736 - 741
• Main Authors: Satheeskanth, Navaratnam, Wijenayake, Chamith, Edussooriya, Chamira U. S.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 08.08.2024
• Subjects: 4-D filters; Computational complexity; Denoising; Frequency-domain analysis; IIR filters; Light fields; low complexity; Maximum likelihood detection; Noise reduction; Nonlinear filters; Passband; Real-time systems
• ISSN: 2691-364X
• DOI: 10.1109/MERCon63886.2024.10688959

Denoising of four-dimensional (4-D) light fields (LFs) is a fundamental preprocessing step before employing LFs for downstream tasks. Most of LF denoising methods have higher computational complexities despite excellent performance. Denoising of LFs using 4-D linear filters is a low-complexity approach that can achieve near real-time or real-time processing. We propose an ultra low-complexity LF denoising methods using 4-D infinite-extent impulse response (IIR) hyperfan filters in this paper. Our approach exploits the sparsity of an LF in the 4-D frequency domain, and employ a set of one-dimensional and two-dimensional first-order IIR filters to approximate the 4-D hyperfan-shaped passband. On average, the proposed 4-D IIR hyperfan filter needs only 2.56 multiplications and 21.06 additions to process a LF sample leading to more than 92% and 64% savings in the number of multiplications and additions to process a LF sample compared previously proposed LF denoising methods based on 4-D linear filters with a \sim 1 \mathrm{~dB} deterioration in the peak-signal-to-noise ratio.