Towards reduction of the training and search running time complexities for non-rigid object segmentation

The problem of non-rigid object segmentation is formulated in a two-stage approach in Machine Learning based methodologies. In the first stage, the automatic initialization problem is solved by the estimation of a rigid shape of the object. In the second stage, the non-rigid segmentation is performed. The rational behind this strategy, is that the rigid detection can be performed at lower dimensional space than the original contour space. In this paper, we explore this idea and propose the use of manifolds to reduce even more the dimensionality of the rigid transformation space (first stage) of current state-of-the-art top-down segmentation methodologies. Also, we propose the use of deep belief networks to allow for a training process capable to produce robust appearance models. Experiments in lips segmentation from frontal face images are conducted to testify the performance of the proposed algorithm.