Method and arrangement for electronic recording of rolled fingerprints

A method for the electronic recording of a moving object which is rolled on a recording surface and has a surface structure that causes a print on the recording surface, wherein the object is detected in a series of high-resolution individual image frames during the object movement by means of a spatially resolving image recording unit and processed as a two-dimensional electronic image, comprising the steps of:

• determining a shape surrounding the object image from the position and size of the object image in the individual image frames read out from the image recording unit;
• determining an enlarged rectangle being oriented parallel to the row direction and column direction of a sensor contained in the image recording unit and being enlarged by tolerance allowances (Δ) calculated from the surrounding shape of the object image and an estimate of the object movement;
• and
• using said enlarged rectangle to adjust an active pixel area being restricted in size and position within the entire sensor area for at least one succeeding image frame being read out subsequently from said active pixel area of the image recording unit, so that the read out active pixel area is always kept small due to its adaptation to the detected shape and movement of the object image and thus a higher image rate is realized in the sensor readout or data transfer.