系统仿真学报 ›› 2022, Vol. 34 ›› Issue (6): 1259-1266.doi: 10.16182/j.issn1004731x.joss.20-1037

• 仿真建模理论与方法 • 上一篇    下一篇

蒙卡渲染画面多特征非局部均值滤波降噪算法

杨凯(), 陈纯毅(), 胡小娟, 于海洋   

  1. 长春理工大学 计算机科学技术学院,吉林 长春 130022
  • 收稿日期:2020-12-23 修回日期:2021-01-28 出版日期:2022-06-30 发布日期:2022-06-16
  • 通讯作者: 陈纯毅 E-mail:741910453@qq.com;chenchunyi@hotmail.com
  • 作者简介:杨凯(1997-),男,硕士生,研究方向为计算机图形学。E-mail:741910453@qq.com
  • 基金资助:
    国家自然科学基金(U19A2063);吉林省科技发展计划(20190302113GX);吉林省教育厅“十三五”科学技术研究项目(JJKH20200792KJ)

Denoising Algorithm Based on Multi-feature Non-local Mean Filtering for Monte Carlo Rendered Images

Kai Yang(), Chunyi Chen(), Xiaojuan Hu, Haiyang Yu   

  1. School of Computer Science and Technology, Changchun University of Science and Technology, Changchun 130022, China
  • Received:2020-12-23 Revised:2021-01-28 Online:2022-06-30 Published:2022-06-16
  • Contact: Chunyi Chen E-mail:741910453@qq.com;chenchunyi@hotmail.com

摘要:

针对蒙特卡罗渲染在低光线路径采样率下绘制的图像容易出现噪点的问题,提出一种蒙特卡罗渲染画面多特征非局部均值降噪算法。使用canny算法对场景反射率图进行梯度化以反射率梯度图为引导图利用引导滤波器对法向量图预滤波求出预滤波后法向量图中图像块之间的结构相似性,利用结构相似性倒数的对数值对非局部均值滤波器权值进行改进;利用改进后的非局部均值滤波器对噪点图像进行滤波重构。实验结果表明:该算法能在典型场景中有效降低渲染画面的噪声,改善均方误差和峰值信噪比质量指标。

关键词: 蒙特卡罗, 渲染, 引导滤波器, 非局部均值滤波器, 结构相似性

Abstract:

Aiming at the rendering noise in Monte Carlo synthesized images induced by the low light-path sampling rate, a denoising algorithm based on the multi-feature non-local-mean filtering is proposed. The gradient image of the scene's albedo information is calculatedwith the canny operator, and a guided filter together with the said gradient image is employed to prefilter the normal vector image. The structural similarity of the sub-blocks in the prefiltered normal vector image is calculated and the improved weights of the non-local mean filter are computed according to the logarithmic value of the reciprocal of the structural similarity. The improved non-local mean filter is used to implement the reconstruction of the noisy image. The experimental results show that the proposed algorithm can effectively reduce the level of Monte Carlo rendering noise in typical scenes, and can improve the metrics of mean square error and peak signal-to-noise ratio.

Key words: Monte Carlo, rendering, guide filter, non-local mean filter, structural similarity

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