# A Color- and Geometric-Feature-Based Approach for Denoising Three-Dimensional Cultural Relic Point Clouds

## TL;DR

This paper introduces a new method to clean up 3D scans of cultural relics by combining color and shape features, resulting in better quality models.

## Contribution

A novel denoising approach for 3D cultural relic point clouds using graph signal processing with color and geometric features.

## Key findings

- The proposed method outperforms five existing denoising techniques in both quality and speed.
- It preserves fine-scale features like texture and ornamentation while removing noise.
- The approach requires fewer iterations and is robust for real-world cultural relic scans.

## Abstract

In the acquisition process of 3D cultural relics, it is common to encounter noise. To facilitate the generation of high-quality 3D models, we propose an approach based on graph signal processing that combines color and geometric features to denoise the point cloud. We divide the 3D point cloud into patches based on self-similarity theory and create an appropriate underlying graph with a Markov property. The features of the vertices in the graph are represented using 3D coordinates, normal vectors, and color. We formulate the point cloud denoising problem as a maximum a posteriori (MAP) estimation problem and use a graph Laplacian regularization (GLR) prior to identifying the most probable noise-free point cloud. In the denoising process, we moderately simplify the 3D point to reduce the running time of the denoising algorithm. The experimental results demonstrate that our proposed approach outperforms five competing methods in both subjective and objective assessments. It requires fewer iterations and exhibits strong robustness, effectively removing noise from the surface of cultural relic point clouds while preserving fine-scale 3D features such as texture and ornamentation. This results in more realistic 3D representations of cultural relics.