3-D object recognition from shadow shape curves

The 3-D object recognition can be normally done by collecting 2-D projections taken at various viewing angles, which requires a large size of database. In this paper we present the 3-D object-recognition approach by analyzing the shadow shape curve of 2-D from horizontal 360/spl deg/ viewing angles, projections which depend on typical characters of objects. The process starts from shooting the subject with the light source behind the subject or a subject with a light background while the subject is being turned around in various viewing angles. The process is independent of the size of the shadow shape curves or position of the subject taken. This process shows the shadow shape curves which are then converted to patterns of slope scores and later matched with the standard slope score patterns in the database. By comparing the sequential aspects of the figure members in the slope patterns with the standard ones, this process can recognize 3-D objects with better than 92 percent of accuracy.