Conditional toggle mappings: principles and applications

International audienceWe study a class of mathematical morphology filters to operate conditionally according to a set of pixels marked by a binary mask. The main contribution of this paper is to provide a general framework for several applications including edge enhancement and image denoising, when it is affected by salt-and-pepper noise. We achieve this goal by revisiting shock filters based on erosions and dilations and extending their definition to take into account the prior definition of a mask of pixels that should not be altered. New definitions for conditional erosions and dilations leading to the concept of conditional toggle mapping. We also investigate algebraic properties as well as the convergence of the associate shock filter. Experiments show how the selection of appropriate methods to generate the masks lead to either edge enhancement or salt-and-pepper denoising. A quantitative evaluation of the results demonstrates the effectiveness of the proposed methods. Additionally, we analyse the application of conditional toggle mapping in remote sensing as pre-filtering for hierarchical segmentation

Spatially adaptive PDEs for robust image sharpening

ISBN: 978-146732533-2International audienceWe present here discrete and continuous partial differential equation (PDE) -based methods for image enhancement/ sharpening. Using more robust and spatially adaptive PDEs, multiscale morphological operators that account image features are introduced, and then, used to provide a discrete enhancement operator, thanks to the former Kramer and Bruckner filter. A novel PDE associated to the introduced enhancement operator is established in 2D. Both the discrete and PDE-based sharpening filters are illustrated on synthetic, binary and real images