s-SBIR: Style Augmented Sketch based Image Retrieval

Sketch-based image retrieval (SBIR) is gaining increasing popularity because of its flexibility to search natural images using unrestricted hand-drawn sketch query. Here, we address a related, but relatively unexplored problem, where the users can also specify their preferred styles of the images they want to retrieve, e.g., color, shape, etc., as key-words, whose information is not present in the sketch. The contribution of this work is three-fold. First, we propose a deep network for the problem of style-augmented SBIR (or s-SBIR) having three main components - category module, style module and mixer module, which are trained in an end-to-end manner. Second, we propose a quintuplet loss, which takes into consideration both the category and style, while giving appropriate importance to the two components. Third, we propose a composite evaluation metric or ncMAP which can quantitatively evaluate s-SBIR approaches. Extensive experiments on subsets of two benchmark image-sketch datasets, Sketchy and TU-Berlin show the effectiveness of the proposed approach.