As ancient documents are being digitized, systems for retrieving documents or images can now be found in Digital Libraries. With regard to illustrations, the content-based image retrieval is difficult and the user often needs to check visually the similarity of the re- trieved images. This process is not entirely reliable since very similar images (impressions, ornamental let- ters) can actually be printed from distinct stamps. No other visualization method exists than the map of pixel- to-pixel gray level difference (PPDMap). We propose here a method that evaluates locally the differences and allows the user to visualize them. It is based on a local adaptation of the Hausdorff distance. Our method per- formance is successfully compared to the PPDMap and an expert difference evaluation assesses our method re- liability.