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, by determining if the respective confidences of at least two of the at least one candidate shape are higher than a first predetermined threshold, and a difference between the respective confidences of the at least two candidate shapes is lower than a second predetermined threshold; in response to determining that the recognizing has the potential error, displaying a user-interface and prompting the user to hand-draw the at least one primitive in said user-interface, wherein the hand-drawn primitive is used as auxiliary information; and re-recognizing the at least one primitive at least in part based on the auxiliary information.