  Freehand line sketches are an interesting and unique form of visual
representation. Typically, such sketches are studied and utilized as an end
product of the sketching process. However, we have found it instructive to
study the sketches as sequentially accumulated composition of drawing strokes
added over time. Studying sketches in this manner has enabled us to create
novel sparse yet discriminative sketch-based representations for object
categories which we term category-epitomes. Our procedure for obtaining these
epitomes concurrently provides a natural measure for quantifying the sparseness
underlying the original sketch, which we term epitome-score. We construct and
analyze category-epitomes and epitome-scores for freehand sketches belonging to
various object categories. Our analysis provides a novel viewpoint for studying
the semantic nature of object categories.
