Intrinsic projector calibration is essential in projection mapping (PM) applications, especially in dynamic PM. However, due to the shallow depth-of-field (DOF) of a projector, more work is needed to ensure accurate calibration. We aim to estimate the intrinsic parameters of a projector while avoiding the limitation of shallow DOF. As the core of our technique, we present a practical calibration device that requires a minimal working volume directly in front of the projector lens regardless of the projector's focusing distance and aperture size. The device consists of a flat-bed scanner and pinhole-array masks. For calibration, a projector projects a series of structured light patterns in the device. The pinholes directionally decompose the structured light, and only the projected rays that pass through the pinholes hit the scanner plane. For each pinhole, we extract a ray passing through the optical center of the projector. Consequently, we regard the projector as a pinhole projector that projects the extracted rays only, and we calibrate the projector by applying the standard camera calibration technique, which assumes a pinhole camera model. Using a proof-of-concept prototype, we demonstrate that our technique can calibrate projectors with different focusing distances and aperture sizes at the same accuracy as a conventional method. Finally, we confirm that our technique can provide intrinsic parameters accurate enough for a dynamic PM application, even when a projector is placed too far from a projection target for a conventional method to calibrate the projector using a fiducial object of reasonable size.
翻译:投影映射( PM) 应用中, 特别是动态 PM 应用中, 自然投影仪校准( PM) 至关重要。 但是, 由于投影仪的浅深度( DOF), 需要做更多的工作来确保精确校准。 我们的目标是估算投影仪的内在参数, 同时避免浅度 DOF 的局限性。 作为我们技术的核心, 我们展示了一个实用的校准装置, 它要求投影器镜头前的微小工作量, 而不管投影器的距离和孔径大小如何。 该装置包括一个平板扫描仪和针孔阵列面具。 对于校准来说, 投影仪的参数是一系列结构化的光度光度模型。 投影仪的方向是向结构上的光度, 仅将常规射镜射程的射影射影仪射精度分解到扫描机的射精度模型。 我们的投影仪甚至投影仪只能投影, 我们通过应用标准摄像仪的精确度校准技术, 将一个高水平的校准率的校准模型, 用来展示一个更精确的校准模型, 。