In proteomics 2?dimensional gel electrophoresis (2?DE) is a separation technique for proteins. The resulting protein spots can be identified by either using picking robots and subsequent mass spectrometry or by visual cross inspection of a new gel image with an already analyzed master gel. Difficulties especially arise from inherent noise and irregular geometric distortions in 2?DE images. Aiming at the automated analysis of large series of 2?DE images, or at the even more difficult interlaboratory gel comparisons, the bottleneck is to solve the two most basic algorithmic problems with high quality: Identifying protein spots and computing a matching between two images. For the development of the analysis software CAROL at Freie Universit?at Berlin we have reconsidered these two problems and obtained new solutions which rely on methods from