基于频谱集中程度的重参数化在光场去噪中的应用  

Spectrum Concentration Based Reparameterization for Light Field Denoising

作　　者：王甜甜[1] 何迪 刘畅[1] 邱钧[1] Wang Tiantian;He Di;Liu Chang;Qiu Jun(Institute of Applied Mathematics,Beijing Information Science and Technology University,Beijing 100101,China)

机构地区：[1]北京信息科技大学应用数学研究所,北京100101

出　　处：《光学学报》2023年第20期241-255,共15页Acta Optica Sinica

基　　金：国家自然科学基金(62001036,61931003,62171044)。

摘　　要：从频谱支集对称程度及夹角两个结构特点出发,分析频谱支集结构变化对于去噪效果的影响,提出光场频谱支集集中程度的概念,并设计相应的度量函数。通过极小化集中程度度量函数,计算合适的光场双平面间距,按照此间距在去噪前对光场数据进行重参数化可以提高滤波去噪效果。HCI模拟光场数据和斯坦福实测光场数据实验结果表明,引入重参数化的光场滤波去噪方法能够优化去噪结果。从视觉上看,在滤除更多噪点的同时保留场景更多的结构和纹理信息;从定量评价上看,峰值信噪比和结构相似度指标也有所提高。Objective Different noise types may be introduced into light field data during acquisition,transmission and processing,due to low light conditions,corrupted pixel values,the statistical nature of electromagnetic waves,faulty memory space in storage,and hardware damage.Data noise seriously affects the accuracy of subsequent light field imaging techniques like depth estimation and post-capture refocusing.Therefore,light field denoising is important in light field imaging.4D dual fan,4D hypercone,and 4D hyperfan are classical filters designed based on the structure of the light field spectrum support.These filters can achieve light field denoising by passing the light field signal on the spectrum support while eliminating a significant amount of noise energy that lies outside the spectrum support.However,the noise suppression effect of the filter is poor for the noise located on the spectrum support,and the aliasing effect on the spectrum support also seriously affects the denoising quality.To further improve the denoising effect of the filters,we explore the structural characteristics of the spectrum support conducive to denoising effect improvement for determining the light field reparameterization.Both the quantitative indicator and the visual effect of the denoising results are improved by reparameterizing the noisy light field properly before denoising.Moreover,the idea of determining the light field reparameterization based on structure characteristics of the spectrum support provides a new perspective for improving the processing effect of light field data.Methods We consider two structural characteristics of the light field spectrum support,including the symmetry degree and the angle between two boundaries of the spectrum support.Analysis of how the two characteristics affect the denoising effect shows that the smaller angle and higher symmetry degree of the spectrum support are beneficial for enhancing the denoising effect.Based on the two structural characteristics,the concentration concept of the light fi

关 键 词：物理光学 光场 重参数化 频谱结构 去噪 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]