A technique for facilitating understanding of a stereoscopic structure of an object in a 3-D image of point cloud data is provided. An image processing device includes a point cloud data display controlling unit, a marker display controlling unit, and a specified point cloud display controlling unit. The point cloud data display controlling unit displays a 3-D image of point cloud data on a screen. The marker display controlling unit displays a marker to specify a cut section of the 3-D image of the point cloud data. The specified point cloud display controlling unit displays a point cloud that constitutes the cut section among the point cloud data, as another image.