Using computers for different task including enhancement, description and evaluation of signals we typically include three steps: signal processing (for obtaining signal of better quality), signal analysis (for extraction and calculation of useful features of the signal), and signal recognition (for classification of signals and for aiding of decision making processes). In paper next step is proposed and presented: automatic understanding of the signal merit content. The idea of Automatic understanding is described on general plane and illustrated using problems taken from the medical imaging problems. As can be shown, automatic understanding of the signals can be used in population investigations (as a filter for preliminary selection patients with problems exacting physicians assistance), or as additional intelligent tool for in depth analysis especially difficult diagnostics problems, as well as new kind of searching machine for content based searching in multimedial databases. In p...