System and method for automated calibration and correction of display geometry and color

摘要

Various embodiments are described herein for a system and method for calibrating a display device to eliminate distortions due to various components such as one or more of lenses, mirrors, projection geometry, lateral chromatic aberration and color misalignment, and color and brightness non-uniformity. Calibration for distortions that vary over time is also addressed. Sensing devices coupled to processors can be used to sense display characteristics, which are then used to compute distortion data, and generate pre-compensating maps to correct for display distortions.

主权项

1. A calibration method to correct for image distortion of a camera that is positioned freely with respect to a viewing surface characterized by an aspect ratio and bounded by a rectangular frame, said method comprising:
displaying at least one test image comprising a set of reference markers with known shapes and coordinates on the viewing surface; acquiring an image of the viewing surface such that the frame is captured in its entirety; identifying the four corners of the frame and the markers, as distorted, in camera image space; obtaining a transformation that corrects for perspective distortion of the acquired image by mapping the images of the four corners of the frame to a second set of four-corners forming a straight rectangle that maintains the aspect ratio and is characterized with an origin and a scale in the camera image space; constructing a calibration grid that maps the identified markers to their respective undistorted positions with respect to the frame, onto the straight rectangle in the camera image space; generating a camera distortion correction map from the calibration grid, that can be applied to all image pixels.