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The technique of dealing with point clouds can be applied in a wide range of fields. In archaeological and historical research, some of the methods are very useful to analyze three-dimensional features of point clouds obtained by three-dimensional measurement of artifacts excavated from ruins. Jomon potteries have various shapes depending on the areas and ages of production. In order to investigate the characteristics of the potteries, analysis methods of the rim parts and surface patterns are required. Generally, rubbing is a technique for copying patterns by applying ink to the paper placed on the surface of the pottery. This is a popular but manual method to copy the patterns of pottery surfaces. On the other hand, if the surface patterns of Jomon potteries can be extracted as digital 3D point clouds, the risk of breakage or soiling of potteries can be reduced. In addition, 3D coordinate point clouds have the advantage that they can be segmented for analyzing necessary parts. Photogrammetry can obtain a 3D coordinate point cloud without contact to an object. Photogrammetry is a technique that can obtain a three-dimensional point set from many photographs of an object taken from various angles and by calculating camera parameters. If earthenware is photographed, not only earthenware surfaces but also its inside and rim can be converted into 3D data at the same time. Introducing photogrammetry avoids manual creation and adjustment of 3D models of the earthenware. However, to use the measured point cloud in the later process such as pattern extraction, it is necessary to segment the surface, mouth rim edge, and inside. In this paper, we propose a method for segmenting an earthenware point cloud obtained by photogrammetry into outer and inner parts, an as an application, we examine a method for extracting the surface pattern in the segmented outer point cloud.
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