Building a Photo-Based Card Grader: Computer Vision Where the LLM Doesn't Pick the Score

Trading-card grading looks like an image-classification problem until you try to build it. A grade is driven by several physical properties at once: how centered the art is, how sharp the corners are, whether an edge is whitening, whether the surface has a fold. Each one lives at a different scale in a phone photo. This is a write-up of how we structured the pipeline behind CardGrade, an app that pre-grades cards from phone photos. Its engine, CGI Vision AI, returns estimated PSA, BGS and CGC grades with confidence scores in about 60 seconds.