@techreport{TR-IC-05-19, number = {IC-05-19}, author = {A.X. Falcão and P.A.V. Miranda and F.P.G. Bergo}, title = {Automatic object detection by tree pruning}, month = {September}, year = {2005}, institution = {Institute of Computing, University of Campinas}, note = {In English, 24 pages. \par\selectlanguage{english}\textbf{Abstract} The Image Foresting Transform (IFT) has been presented for the design of image processing operators based on connectivity. The IFT reduces image processing problems into a minimum-cost path forest problem in a graph derived from the image. In this paper we propose a new image operator, which solves segmentation by pruning trees of the forest. An IFT is applied to create a minimum-cost path forest whose roots are seed pixels, selected inside a desired object. In this forest, the background consists of a few subtrees rooted at pixels (leaking pointsq) on the object's boundary. The leaking pixels are identified and their subtrees are eliminated, such that the remaining forest defines the object. Tree pruning reduces image segmentation to the choice of a few pixels in the image, favoring solutions for automatic object detection. We present a user-friendly way of identifying leaking pixels and give solutions for their automatic detection. Since automatic seed selection may be different for each application, we evaluate automatic segmentation with tree pruning in three situations: labeling of multiple objects with similar textures, 3D object definition, and shape-based object detection. The results indicate that tree pruning is a promising approach to investigate automatic image segmentation. } }