1. A method, comprising: capturing one or more of image data depicting a digital representation of a document and audio data relating to the digital representation of the document; defining a plurality of candidate edge points within the image data; removing one or more outlier candidate edge points from the plurality of candidate edge points; defining a second plurality of candidate edge points excluding the one or more outlier candidate edge points; and defining four sides of a tetragon based on one or more of the plurality of candidate edge points and the second plurality of candidate edge points, wherein each side of the tetragon corresponds to a different side of the document, and wherein the tetragon bounds the digital representation of the document.
10. The method as recited in claim 1 , wherein each side of the tetragon is characterized by a polynomial equation, and wherein the defining comprises determining one or more coefficients for each polynomial equation.