Abstract: The accuracy of real estate area surveying and mapping results is of great significance to safeguarding the rights and interests of both parties in real estate transactions. For buildings with complex and irregular indoor spaces, it is difficult to obtain the indoor effective area efficiently and accurately using traditional measurement methods such as laser rangefinders and tape measures. Taking the indoor area surveying and mapping project of a loft building with a special-shaped internal space as an example, a handheld 3D laser scanner is used to quickly obtain massive indoor point cloud data, and a region growing algorithm is proposed to automatically extract the indoor floor model of the building based on the ground model. It can solve the outline of the internal space with a height greater than 2.2 m, and then extract the outline point cloud of the effective indoor building area of the building. Use the point cloud to draw the outline of the effective area through human-computer interaction and other methods, and finally calculate the effective indoor real estate area of the building. Compared with traditional real estate measurement methods, the use of handheld 3D laser scanners for on-site operations is not only highly efficient, but the massive point cloud data obtained can also more comprehensively reflect the indoor spatial structure of special-shaped buildings, and the calculated property area is also more accurate.

Key words: 3D laser scanning, property area, alien building, SLAM, point cloud