User-friendly inter-pupillary distance calibration method using a single camera for autostereoscopic 3D displays

Abstract

The accurate inter-pupillary distance (IPD) of a user plays an important role and is a prerequisite for eye-tracking-based autostereoscopic three-dimensional (3D) display systems by calculating the precise 3D eye position of the users. We aimed to develop a robust computer-aided algorithm for each user-specific IPD calibration using a single camera in a user-friendly manner. Our algorithm consists of eye tracking, pattern rendering, user pattern selection, and IPD adjustment according to the selected patterns. Two stereo patterns were designed to clearly show the IPD differences: a 3D stereo registration pattern and a complimentary stereo pattern. We applied this algorithm to 21 users. The reference standard was provided by a commercial pupilometer. The IPD values obtained by the proposed method and the reference standard IPD values were not statistically different (64.9 ± 4.1 mm from the algorithm and 64.2 ± 3.4 mm from the reference standard, p = 6.64) from the students' t-test. A good agreement was observed among the 21 users in using the IPD calibration software with an agreement of 94.8% (kappa 0.89, 95% confidence interval from 0.83 to 0.96, and p < 0.0001). Our algorithm shows promising results in IPD calibration using a single camera in a user-friendly manner.