Interactive image segmentation

Segmentation of objects from still images has many practical applications. In the past decade, combinatorial graph cut algorithms have been successfully applied to get fairly accurate object segmentation, along with considerable reduction in the amount of user interaction required. In particular, the Grabcut algorithm has been found to provide satisfactory results for a wide variety of images. This work is an extension to the Grabcut algorithm. The Grabcut algorithm uses Gaussian mixture models to fit the color data. The number of Gaussian components used in mixture model is however fixed. We apply an unsupervised algorithm for estimating the number of Gaussian components to be used for the models. The results obtained show that segmentation accuracy is increased by estimating the Gaussian components required, prior to applying the Grabcut algorithm

Improved GrabCut segmentation via GMM optimisation

Semi-automatic segmentation of still images has vast and varied practical applications. Recently, an approach "GrabCut" has managed to successfully build upon earlier approaches based on colour and gradient information in order to address the problem of efficient extraction of a foreground object in a complex environment. In this paper, we extend the GrabCut algorithm further by applying an unsupervised algorithm for modelling the Gaussian Mixtures that are used to define the foreground and background in the segmentation algorithm. We show examples where the optimisation of the GrabCut framework leads to further improvements in performance