Jorissen Lode, Jackin Boaz Jessie, Oi Ryutaro, Wakunami Koki, Okui Makoto, Ichihashi Yasuyuki, Lafruit Gauthier, Yamamoto Kenji, Bekaert Philippe
Appl Opt. 2019 Feb 1;58(4):1200-1209. doi: 10.1364/AO.58.001200.
Recent advances in the creation of microlens arrays as holographic optical elements allow the creation of projector-based see-through light field displays suitable for augmented reality. These systems require an accurate calibration of the projector with relation to the microlens array, as any small misalignment causes the 3D reconstruction to fail. The methods reported so far require precise placement of the calibration camera w.r.t. the lens array screen, which affects the display configuration. We propose a calibration approach which is more robust, and which allows free camera placement. Hence, it does not limit the capabilities of the system. Both a homography-based technique and structured light play a central role in realizing such a method. The method was tested on a projection-based integral imaging display system consisting of a consumer-grade projector and a digitally designed holographic optical element based micromirror array screen. The calibration method compensates for the lens distortion, intrinsics, and positioning of the projector with relation to the screen. The method uses a single camera and does not require the use of obtrusive markers as reference. We give an in-depth explanation of the different steps of the algorithm, and verify the calibration using both a simulated and a real-world setup.
作为全息光学元件的微透镜阵列制造方面的最新进展，使得能够创建适用于增强现实的基于投影仪的透视光场显示器。这些系统需要对投影仪与微透镜阵列进行精确校准，因为任何微小的未对准都会导致三维重建失败。迄今为止报道的方法需要校准相机相对于透镜阵列屏幕的精确放置，这会影响显示配置。我们提出了一种更稳健的校准方法，它允许相机自由放置。因此，它不会限制系统的功能。基于单应性的技术和结构光在实现这种方法中都起着核心作用。该方法在基于投影的积分成像显示系统上进行了测试，该系统由消费级投影仪和基于数字设计的全息光学元件的微镜阵列屏幕组成。该校准方法补偿了透镜畸变、投影仪的固有特性以及投影仪相对于屏幕的定位。该方法使用单个相机，并且不需要使用显眼的标记作为参考。我们对算法的不同步骤进行了深入解释，并使用模拟和实际设置验证了校准。
