An Incremental Target-Adapted Strategy for Active Geometric Calibration of Projector-Camera Systems

Abstract

The calibration of a projector-camera system is an essential step toward accurate 3-D measurement and environment-aware data projection applications, such as augmented reality. In this paper we present a two-stage easy-to-deploy strategy for robust calibration of both intrinsic and extrinsic parameters of a projector. Two key components of the system are the automatic generation of projected light patterns and the incremental calibration process. Based on the incremental strategy, the calibration process first establishes a set of initial parameters, and then it upgrades these parameters incrementally using the projection and captured images of dynamically-generated calibration patterns. The scene-driven light patterns allow the system to adapt itself to the pose of the calibration target, such that the difficulty in feature detection is greatly lowered. The strategy forms a closed-loop system that performs self-correction as more and more observations become available. Compared to the conventional method, which requires a time-consuming process for the acquisition of dense pixel correspondences, the proposed method deploys a homography-based coordinate computation, allowing the calibration time to be dramatically reduced. The experimental results indicate that an improvement of 70% in reprojection errors is achievable and 95% of the calibration time can be saved.

High-Coverage 3D Scanning through Online Structured Light Calibration

“…The underlying idea is to allow the camera to localize the target, while using the pattern to map individual projector pixels. This is the case, for instance, with the approach recently proposed by Chien et al [1], where a virtual checkerboard is projected onto a real one and an iterative correction loop is performed on the projector parameters until the camera detect a perfect overlap between the virtual and physical target. Chen and Xi [2] adopt a target made up of a grid of regular dots, which are easy do detect and located accurately.…”

Accurate projector calibration method by using an optical coaxial camera

“…Chen and Chien presented a two-stage easy-to-deploy strategy to robustly calibrate both intrinsic and extrinsic parameters of a projector [7]. Because of an iterative procedure, this method is complicated in actual application.…”

“…The second category of projector calibration is to find one homography transformation between a calibration plane and the projector image plane [7][8][9]. Chen and Chien presented a two-stage easy-to-deploy strategy to robustly calibrate both intrinsic and extrinsic parameters of a projector [7].…”

Projector calibration method based on optical coaxial camera

“…Chen et al presented a two-stage easy-to-deploy strategy to robustly calibrate both intrinsic and extrinsic parameters of a projector [9]. Based on the incremental strategy, the calibration process first establishes a set of initial parameters, and then it iteratively upgrades these parameters incrementally using the projected and captured images of dynamically-generated calibration patterns.…”

“…The second category of projector calibration is to find one homography transformation between a calibration plane and the projector image plane [8][9][10]. Chen et al presented a two-stage easy-to-deploy strategy to robustly calibrate both intrinsic and extrinsic parameters of a projector [9].…”