Morphological contrast enhancement using connected transformations

In this work a connected approach for morphological contrast enhancement is proposed. The morphological contrast is based on the notion of toggle mappings. The notion of toggle mappings progressed in the way suggested by the Kramer and Bruckner (KB) algorithm. Since the KB algorithm uses the erosion and the dilation as patterns, some problems in this transformation are the oscillations and jumps produced when it is iterated. In our case, both transformations (erosion and dilation) were used in a separated way to built a family of filters, called morphological slope filters (MSF). This allows a better control of the output image. However, sometimes the MSF are sensible to some configurations of the blurred edge. This inconvenience can be attenuated using a connected approach of MSF. Since a connected operator does not split components of the level sets, then connected operators must act on the level of flat zones rather than on pixel level. The notion of flat zone allows the attenuation in sensibility of the MSF. The interest of the use of connected transformations in contrast enhancement is illustrated when a modified version of the KB algorithm is tested and by comparing idempotent toggles using flat zone and pixel notions.