We propose an efficient computational method to acquire diffuse and specular normal map with three types of illumination patterns by removing the redundancy of the conventional method. By analyzing the relationship between four reflectances under  XY Z -gradient and constant patterns, the number of patterns needed is reduced to three patterns.
['Byeongjoo Ahn', 'Junghyun Cho', 'Taekyung Yoo', 'Ig-Jae Kim']
Reduced illumination patterns for acquisition of specular and diffuse normal maps