Camera-Assisted Two Dimensional Keystone Correction

摘要

A system and method for facilitating keystone correction in a given model of projector having an attached camera is disclosed. System calibration determines intrinsic and extrinsic parameters of the projector and camera; then control points are identified within a three-dimensional space in front of a screen. The three-dimensional space defines a throw range and maximum pitch and yaw offsets for the projector/screen combination. At each control point, the projector projects a group of structured light elements on the screen and the camera captures an image of the projected pattern. These images are used to create three-dimensional look-up tables that identify a relationship between each image and at least one of (i) pitch and yaw offset angles for the respective control point and (ii) a focal length and a principal point for the respective control point. The given model projectors use the tables in effectuating keystone correction.

主权项

1. A method for effecting keystone correction on a projector, the method comprising:
using a given model of projector that has a camera attached thereto in a known relationship to project a group of structured light elements on a screen; capturing the projected group of structured light elements using the camera; using the received image and a plurality of three-dimensional look-up tables (LUTs) stored on the given model of projector to determine the effective focal length and principal point of the given model of projector; and determining a pitch offset angle and a yaw offset angle between the given model of projector and the screen to effectuate keystone correction.