An iterative spectral-spatial bayesian labeling approach for unsupervised robust change detection on remotely sensed multispectral imagery

kogs-www.informatik.uni-hamburg.de/projects/Censis.html Abstract In multispectral remote sensing, change detection is a central task for all kinds of monitoring purposes. We suggest a novel approach where the problem is formulated as a Bayesian labeling problem. Considering two registered images of the same scene but different recording time, a Bayesian probability for ' Change ' and ' NoChange ' is determined for each pixel from spectral as well as spatial features. All necessary parameters are estimated from the image data itself during an iterative clustering process which updates the current probabilities. The contextual spatial features are derived from Markov random field modeling. We define a potential as a function of the probabilities of neighboring pixels to belong to the same class. The algorithm is robust against spurious change detection due to changing recording conditions and slightly misregistered high texture areas. It yields successful results on simulated and real multispectral multitemporal aerial imagery.

Elisabeth-Mann-Borgese-Meerespreis Schleswig-Holstein : mehr Wissenschaft, mehr Wirtschaft

Der Elisabeth Mann-Borgese-Preis wird seit 2006 an Persönlichkeiten verliehen, die durch ihr politisches, wissenschaftliches oder gesellschaftliches Engagement auf die zentrale Rolle der Meere und deren Erhalt und Schutz aufmerksam gemacht haben. Der Preis, benannt nach der Tochter des Schriftstellers Thomas Mann, ist mit 20.000 Euro dotiert. Der Preis wurde offiziell am 6. Oktober im Rahmen einer Feierstunde in Kiel verliehen

The Impact of Motion Correction on Lesion Characterization in DCE Breast MR Images

ABSTRACT In the context of dynamic contrast enhanced breast MR imaging we analyzed the effect of motion compensating registration on the characterization of lesions. Two registration techniques were applied: 1) rigid registration and 2) elastic registration based on the Navier-Lamé equation. Interpreting voxels that exhibit a decline in image intensity after contrast injection (compared to the non-contrasted native image) as motion outliers, it can be shown that the rate of motion outliers can be largely reduced by both rigid and elastic registration. The performance of lesion features, including maximal signal enhancement ratio and variance of the signal enhancement ratio, was measured by area under the ROC curve as well as Cohen's κ and showed significant improvement for elastic registration, whereas features derived from rigidly registered images did not in general exhibit a significant improvement over the level of unregistered data

The Color Constancy Problem: An Illumination Invariant Mapping Approach

Abstract. We suggest a novel approach to the Color Constancy Problem for multispectral imagery. Our approach is based on a dichromatic illumination model and lters out all spectral information which possibly stems from the illumination rather than from the re ectance of a given surface. Instead of recovering the re ectance signal, the suggested mapping produces a new only surface re ectance-dependent descriptor which isinvariant against varying illumination. Sole input is the relative direct to di use illumination spectrum, no assumptions about the possible re ectance spectra are made. The mapping is a purely pixel based, fast, one-pass matrix operation and can preprocess multispectral images in order to segment them into regions of homogeneous re ectance, unperturbed by varying illumination conditions.