Dynamic Facial Projection Mapping (DFPM) overlays computer-generated images onto human faces to create immersive experiences that have been used in the makeup and entertainment industries. In this study, we propose two concepts to reduce the misalignment artifacts between projected images and target faces, which is a persistent challenge for DFPM. Our first concept is a high-speed face-tracking method that exploits temporal information. We first introduce a cropped-area-limited inter/extrapolation-based face detection framework, which allows parallel execution with facial landmark detection. We then propose a novel hybrid facial landmark detection method that combines fast Ensemble of Regression Trees (ERT)-based detections and an auxiliary detection. ERT-based detections rapidly produce results in 0.107 ms using temporal information with the support of auxiliary detection to recover from detection errors. To train the facial landmark detection method, we propose an innovative method for simulating high-frame-rate video annotations to address the lack of publicly available high-frame-rate annotated datasets. Our second concept is a lens-shift co-axial projector-camera setup that maintains a high optical alignment with only a 1.274-pixel error between 1 m and 2 m depth. This setup reduces misalignment by applying the same optical designs to the projector and camera without causing large misalignment as in conventional methods. Based on these concepts, we developed a novel high-speed DFPM system that achieves nearly perfect alignment with human visual perception.

The growing need for high-frame-rate projectors in the fields of dynamic projection mapping (DPM) and three-dimensional (3D) displays has increased. Conventional methods allow for an increase in the frame rate to as much as 2,841 frames per second (fps) for 8-bit image projection, using digital light processing (DLP) technology when the minimum digital mirror device (DMD) control time is $44 \mu \mathrm{s}$. However, this rate needs to be further augmented to suit specific applications. In this study, we developed a novel high-frame-rate projection method, which divides the bit depth of an image among multiple projectors and simultaneously projects them in synchronization. The simultaneously projected bit images are superimposed such that a high-bit-depth image is generated within a reduced single-frame duration. Additionally, we devised an optimization process to determine the system parameters necessary for attaining maximum brightness. We constructed a prototype system utilizing two high-frame-rate projectors and validated the feasibility of using our system to project 8-bit images at a rate of 5,600 fps. Furthermore, the quality assessment of our projected image exhibited superior performance in comparison to a dithered image.