Joint keystone correction and shake removal for a hand held projector

Abstract

Images projected on to a planar projection surface undergoes keystone distortion when projector is not perpendicular to projection surface. Further in the case of handheld projector, the projected image does not remain steady on the surface due to shaky movements of the hand. This paper introduces a simple approach to stabilise such shaking images using an additional inertial measurement unit (IMU) consisting of gyroscope and accelerometer sensors attached into handheld projector. The approach explicitly estimates the transformation between projector plane and projection surface through out the perturbation of projector, which is used for calculating the prewarped image. Attached IMU gives the rotation angles along all 3 axes. These angles are used in estimating the prewarping transformation. A novel approach has been presented for solving the stabilization problem for a shaking projector in both calibrated and uncalibrated setting. We demonstrate the effectiveness of this approach in getting a stabilized and keystone corrected image on a planar surface continuously with good accuracy in real time compared to existing methods.