Texture anomaly detection in radar imagery

A radar image of the land or sea will contain extended regions of apparently homogeneous textures arising from, for example, forested areas or uniformly driven expanses of water. However, such regions may contain subtle texture anomalies which indicate the presence of a feature of interest such as a change in tree density due to environmental effects, damping of the sea surface due to the presence of pollutants or the presence of land-based or maritime military targets. For this reason, it is of interest to develop methods of detecting anomalies in textured regions. A strategy for texture anomaly detection is to estimate the multi-variate probability density function (PDF) of a texture segment using the whole homogeneous region as training data and then to calculate the likelihood of occurrence of each individual segment within the region given the PDF estimate. Those texture segments with anomalous likelihood values can then be flagged as potential texture anomalies