Research on the method of locating and unwrapping the Center Point of Pipeline Inner Wall Image based on Linear projection

In order to obtain a clear panoramic, unfold image of the inner wall in the video pipeline inspection system, the problems of camera center point offset and panoramic image distortion must be solved. In view of the above situation, this paper proposes an optimized unwrapping method for the undistorted estimation of string image in the case of camera eccentricity. In this method, the central coordinates of the pipe string image are located automatically by the Otsu algorithm and region marking method, and the three-dimensional pipe linear projection model is established by the proportion relationship before and after the pinhole camera imaging. Combined with the image region coordinate mapping, the panoramic image of the circular pipe is expanded without distortion. The experimental results show that the unfolded image has high definition and each pixel represents the same physical size, which provides a basis for the subjective evaluation of pipeline inner wall detection and lays a foundation for subsequent quantitative analysis.