The wavefront reconstruction of hologram and holographic stereogram are analyzed to compare their imaging properties, and 'phase added stereogram' (PAS) is proposed as a technique for the calculation of computer generated hologram (CGH). Applying PAS, computer graphics techniques, for example, surface shading and hidden surface removal are easily applied in CGH generation process. The amount of computation is reduced compared with actual hologram calculation, and the quality of reconstructed image is superior to that of holographic stereogram. The theoretical expression of PAS is presented, and experimental results are also demonstrated.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.