Interpretation and ambiguity resolution in Sketch-Based Interfaces

Drawing is a simple, common, and expressive way to represent concepts, relationships and information. The most natural and convenient way to input graphic objects is to draw sketches on a tablet using a pen, just like drawing on a real sheet of paper. However, the multiple interpretations and the possibility to revise the sketch make very difficult to determine the correct interpretation of the users goals. This paper treats ambiguities and their solution. It starts from the assumption that the sketched piture is given by an array of pixels and the graphica components are represented by black pixels on a white background. The sketch representation is based on cosing horizontal sequences of black pixels identified in the image. The interpretation process of the sketch consists of three steps: the first one identifies the horizontal sequences of black pixels and stores them in a list L, the second step reads the list L, recognizes and stores the grapphical components in different lists classified by types, the third step permits the interpretation on the sketch evolution.