A kind of perspective image correction method

Abstract

The invention discloses a perspective image correction method, comprising the steps of: (1) installing a flat plate structure on the imaging path of an X-ray machine, and setting several groups of collinear marking points on the plate structure; (2) perspective imaging , extract the image coordinates of all marked points, and partition to obtain the central area and its outer area; (3) adopt a first-order radial distortion correction model based on cross-ratio invariance for the central area, and calculate the correction coefficient, and based on this Calculate the theoretical undistorted coordinates of all marked points in the central area; (4) Calculate the theoretical undistorted coordinates of marked points in the outer area according to the cross-ratio invariance and design parameters; (5) Establish a correction model and solve the high-order Polynomial mapping model. The invention directly completes the correction for a single perspective image after the end cover of the X-ray machine image multiplier has a shell with specific steel ball arrangement, and has important application value in the surgical robot system based on the shadow multiplier X-ray machine.

Description

technical field [0001] The invention relates to the field of image processing, in particular to a perspective image correction method. Background technique [0002] As one of the large-scale medical equipment in the operating room, the C-arm X-ray machine has been widely used in various orthopedic operations because of its advantages of being able to perform perspective imaging and store the images taken at any time. And in recent years, orthopedic surgical robots with auxiliary positioning have also been developed rapidly, and have been gradually applied in actual orthopedic clinical operations, while C-arm X-ray machines have become an indispensable and important imaging component in orthopedic surgical robot systems. Accuracy also directly affects the navigation and positioning accuracy of the entire surgical robot system. [0003] The intensified X-ray machine has become the first choice of major surgical robot research and development companies because of its low price...

AI Technical Summary

Problems solved by technology

[0003] The intensified X-ray machine has become the first choice of major surgical robot research and development companies because of its low price, stable function, and convenient maintenance. However, the C-arm X-ray machine will definitely produce images during the imaging process through the lens in the intensifier. Distortion causes the position of each pixel in the original image to shift, which does not conform to the law of perspective imaging, making the image unable to be applied to high-precision navigation and positioning occasions. How to correct or reduce the distortion in the process of X-ray machine perspective imaging has also become a problem. One of the problems that must be solved in the surgical robot system with high precision navigation and positioning

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