3D扫描及颜色测量技术在珍珠分选的应用

Application of 3D Scanning Technique and Colour Measurement on Pearl Sorting

基于3D扫描技术及色度测量CIEL^*a^*b^*技术,提出了珍珠的数字化分选方法,从而可以有效克服传统人工筛选的弊端。通过非接触式3D扫描技术获取珍珠的点云数据,并对数据进行拼接处理,得到完整的珍珠三维模型以及珍珠的大小、形状、光洁度对应数据。分光光度计可对珍珠颜色及光泽度进行测量并且进行基于标准色空间CIEL^*a^*b^*的转换,获得可量化指标。利用该技术,企业可根据实际情况并结合国家分级标准GB/T 18781-2008对不同等级珍珠标准品的大小、形状、光洁度、颜色及光泽度进行测量及数据录入,运用算法对样品的测量数据与标准品的数据进行阈值判别,从而实现数字化分选。本文通过实验验证了3D扫描及颜色测量技术在珍珠分选上具有较高的可行性,且未来二者的结合对于珍珠企业实行批量化机械分选,实现自动化生产,缩减生产成本具有巨大潜力。

An original method for automatic pearl sorting is proposed based on 3D scanning technique and CIE L ^*a^*b^* colorimetry, which is able to overcome the shortcomings of manual pearl sorting. The point cloud data of pearl will be extracted by non-contact 3D scanner and processed to splicing module to obtain a three-dimensional (3D) pearl model. The information of size, shape and surface perfection has been involved in the 3D model. The numerical colour as well as luster data of pearl is measured and converted by the colorimeter base on the standard colour space CIE L^*a^*b^*. Pearl companies are able to test and record the standard samples from various detection ranges on the five factors mentioned above based on the judgement index of national pearls grading standard GB/T 18781-2008, and then calculate the threshold between the standard samples and other samples using corresponding algorithm to achieve automatic sorting. The authors verified the high feasibility for automatic pearl sorting using 3D scanning and colour measurement technology based on experiments. Furthermore, the integration of the two technologies has great potential for pearl companies to implement mechanical sorting, realize automatic production and reduce production costs in the future.