Vehicle door appearance detection method based on machine vision

The invention provides a vehicle door appearance detection method based on machine vision, and belongs to the field of appearance detection methods, and the method comprises the steps: copying a filtered vehicle door welding appearance image, and setting the images before and after copying as an image 1 and an image 2; zooming the image 1, inputting the zoomed image 1 into a neural network A, outputting an image defect confidence coefficient, comparing the image defect confidence coefficient with a set threshold value A, counting and marking welding defects, and grading the welding defects to obtain a welding defect grading result; and performing color channel conversion on the image 2, performing segmentation to obtain image blocks, extracting welding area features, normalizing the welding area features into color features, inputting the color features into a neural network B, outputting an image non-welding probability, comparing the image non-welding probability with a set threshold B, performing statistic