Ask HN: Searching for a specific JavaScript graphics library

Maybe off-topic but I don't know where else to turn: a couple of years ago I discovered a JavaScript graphics library that took a shape drawn roughly by hand (e.g. a square raster image) and created a perfect square object, which could then be scaled, rotated, etc. I searched all over GitHub but couldn't find it. Would anyone here know what it is/called and where to find it? I believe it relied on HTML 5 and <canvas>. Thanks much.