1. A method for recognizing a primitive in an image, the method comprising: recognizing, with a processing device at least one primitive in the image to obtain at least one candidate shape of the at least one primitive, the at least one candidate shape having a respective confidence; determining, based on the confidence, whether the recognizing of the at least one primitive has a potential error; in response to determining that the recognizing has the potential error, obtaining auxiliary information about the at least one primitive from a user; and re-recognizing the at least one primitive at least in part based on the auxiliary information.