Systems and methods for detecting document contours in a digital image. An example method may involve: receiving an image comprising one or more documents and detecting a set of lines in the image; identifying a plurality of intersection points corresponding to the set of lines; determining a vanishing point based on the plurality of intersection points; generating a candidate polygon based on the set of lines; evaluating the candidate polygon based on a parameter associated with the vanishing point; and indicating the candidate polygon represents a contour of one of the one or more documents.