基于点云数据的瘢痕长度测量方案

Scar length measurement scheme based on point cloud data

瘢痕鉴定是法医工作中重要的一项任务,对瘢痕的纹理、位置和长度等信息都有着细致的规定和要求。通过三维扫描仪可以便捷地获取点云数据,还原瘢痕区域的具体结构,为瘢痕鉴定提供新的工具。本文基于三维点云数据,提取瘢痕的趋势线,进行瘢痕长度测量。该方案首先对三维瘢痕数据进行投影,在二维平面上提取瘢痕的端点和关键点。然后在三维曲面上通过近邻搜索和向量内积的方法,依次连接所有关键点得到沿瘢痕表面的趋势线,计算瘢痕的长度。本文实验中使用的三维瘢痕点云来自某法医司法鉴定中心的工作内容,通过三维扫描仪提取。在实验数据上的应用结果显示,提取的趋势线在瘢痕表面贴合程度较好,可以跟随曲面进行弯折,可靠性很高。以点为核心的计算方法,在后续测量功能改进中也有较大的空间。

Scar identification is an important task in forensic work. There are detailed regulations and requirements for the texture, location and length of scars. The three-dimensional scanner can easily obtain point cloud data, restore the specific structure of the scar area. These facts provide a new tool for scar identification. Based on the 3 D point cloud data, this paper extracts the trend line of the scar and measures the length of the scar. This program first projects the 3 D scar data, and extracts the endpoints and key points of the scar on a 2 D plane. Then on the 3 D surface, through the method of nearest neighbor search and vector inner product, all the key points are connected in turn to obtain the trend line along the scar surface, and the length of the scar is calculated. The 3 D scar point cloud used in the experiment in this article comes from the work of a forensic appraisal center, and is extracted by a 3 D scanner. The application results on the experimental data show that the extracted trend line fits well on the surface of the scar and can be bent following the curved surface with high reliability. The point-based calculation method also has more room for improvement in subsequent measurement functions.