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 facilitating keystone correction in a projector, comprising:
performing system calibration of a given model of projector that has a camera attached thereto in a known relationship, the system calibration determining intrinsic and extrinsic parameters of the given model of projector and the camera; identifying, within a three-dimensional space in front of a screen, a plurality of control points, wherein the three-dimensional space defines a throw range of the given model of projector and further defines a maximum pitch offset and a maximum yaw offset of the given model of projector from the plane of the screen; for each of the plurality of control points, placing the given model of projector at the control point, projecting a group of structured light elements on the screen using the given model of projector, and capturing an image of the projected pattern with the camera; using the captured images to create a plurality of three-dimensional look-up tables (LUTs) that identify a relationship between an image captured at a given control point and at least one of (i) pitch and yaw offset angles associated with the given control point and (ii) a focal length and a principal point associated with the given control point; and storing the LUTs in a memory in the given model of projectors for use in effectuating keystone correction.