How I Built a Document Detector in the Browser

Scanning a document with your phone is one of those small tasks that comes up all the time. You need a decent photo of a page, and you need to send it somewhere quickly - by email, in a messenger, wherever. Usually that means reaching for an app. Modern browsers can run fairly serious code with WASM, so in some cases opening a site is easier than installing yet another app. It turned out to be a good computer vision problem. Real photos of documents are messy in all the usual ways: perspective d