Antipodal gray codes for structured light

A Gray code and its variants are popular code-patterns for a structured light system. An n-bit Gray code is a kind of binary code whose adjacent code-strings differ only in one bit position. We introduce a specified Gray code, called an 'antipodal Gray code.' Since the n-bit antipodal Gray code has the additional property that the complement of any code-string appears exactly n steps away in the list, the spatial frequency (the width between the white and black stripes) of the antipodal Gray code-pattern is similar along frames. In this paper, we describe the limitations of structured light and the criteria for robust codes. We evaluate the original and antipodal Gray codes, and the experimental results show that the antipodal Gray code provides more robust and accurate results than original Gray codes.