Rail transit electric appliance cabinet door plate size and defect detection method based on machine vision

The invention discloses a rail transit electric appliance cabinet door plate size and defect detection method based on machine vision, and the method comprises the steps: collecting and preprocessing an image, collecting a door plate image through an industrial camera, and carrying out the filtering, denoising and sharpening of the collected image; extracting a door plate contour image in the door plate image, fitting an oblique external envelope line of the door plate contour by using the door plate contour, determining a segmentation point of the door plate contour by using a nearest neighbor search algorithm, and determining four corner points of the door plate as reference points; coordinates of each segmentation point are determined, and the integrity of the door plate contour image is calculated at the same time; calculating the distance from the midpoint of the contour line to the fitting straight line as the edge straightness of the edge; vertical plane scanning is carried out through infrared light,