Automatic geometric correction method of surface projection based on image recognition

Abstract

The invention relates to an image-identification-based automatic geometric correction method for curved surface projection. A camera is arranged to face the center of a projection screen and is connected to a computer; a projector projects a projection image including at least four identifiable positioning green square blocks, the camera collects the image and identifies and localizes a color block position, and a homography matrix H between camera image space and projector image space is calculated; a full-black image is projected on the projector, N*N infrared laser pens are used for projection at horizontal and vertical equally-dividing points of a target projection region of the projection screen to form an N-row N-column laser dot matrix; the camera collects one frame of image, identifies the location of an infrared laser dot matrix location, and records a location set Cd{Cd1, Cd2...Cdi}; according to the homography matrix H, back calculation of a location set Ps of the intersection point location set Cd in the image space of the projector is carried out; a Bezier surface using as a projection curved surface is established in the image space of the projector by using opengl, the projection picture is mapped to the opengl Bezier surface in a texture manner, the location set Ps of the image space of the projector is used as N-row N-column control points of three-times Bezier surface to form a projection curved surface, thereby completing geometric correction. Therefore, non-linear curved surface geometric correction can be processed automatically; equipment is available; and the effect is good.

Description

technical field [0001] The invention relates to an automatic geometric correction method for curved surface projection based on image recognition, which has good signal orientation and is universal and easy to implement, and belongs to the technical field of virtual reality multi-channel projection display. Background technique [0002] Projection multi-channel fusion means that two or more projectors achieve an overall larger picture enhancement effect through edge fusion. After the projection adopts the edge fusion technology, it can be applied to the command and monitoring center, network management center, video conferencing, academic reports, technical lectures and multi-functional conference rooms, mainly suitable for specific needs of large screen, multi-color, high brightness, high resolution, etc. super large place. [0003] In the process of projection multi-channel fusion, due to the use of flat screens, ring screens and ceiling hanging projection methods, the sh...

AI Technical Summary

Problems solved by technology

Manual adjustment is mainly carried out by manually dragging the control points of the projected surface. Generally, hundreds or even thousands of control points need to be repeatedly operated. The debugging process is complex, cumbersome, time-consuming, and the effect is not easy to control. It requires high experience for debugging personnel; Another method to obtain the homography matrix between the projector and the projection screen through camera calibration, through the reconstruction of the projection screen, calculate the pre-distortion matrix to achieve the purpose of geometric correction of the surface, which can automatically correct the surface of the projection screen to a certain extent However, this method needs to calibrate the camera and projector used in advance, and the whole process is more complicated, and the engineering implementation is not easy to control; therefore, there is an urgent need for the adjustment of the projected surface nonlinear geometric correction. , easy to operate and effective implementation

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