Multiscale Visual Object Detection for Unsupervised Ubiquitous Projection Based on a Portable Projector-Camera System

Ubiquitous projection is the recent effort that tries to close the gap between the physical world and the virtual world by using a mobile projector. Using a projector and camera together has a conflict of preferred light conditions, making it difficult to implement a robust visual detector while retaining ubiquity. In this paper, we focus on techniques of visual object detection for a portable projector-camera system. The goal is to create a visual detector that requires no guidance from a user and is robust to different light conditions. Our investigation involves the multiscale concept using Canny edge detection as a representative detector. Five image simplification filters applied to the multiscale detection are examined for both accuracy and speed. In addition, preprocessing using histogram equalization and post processing are applied to ensure robustness in a real-world scenario, and to guarantee that the detection will always successfully detect objects using a constant set of parameters defined offline. Finally, we showed that using multiscale detection in a parallel manner can speed up the detection while not affecting the accuracy of the detection.