Abstract: In this paper, a kind of method which can evaluate fingerprint picture quality was proposed and used in the construction of basic and improved fingerprint key extraction scheme. The method measures the concentration ratio of energy in spectrum picture and the quality of fingerprint picture is denoted by the sum of all the points which have high energy. Key extraction experiment was done on the URU4000B database of Institute of Automation of Academia Sinica and FVC2004 DB3，performance of basic key extraction scheme and improved key extraction scheme were tested. The result shows that the improved scheme is better in key extraction success rate. For example, in URU4000B, when the key extraction failure rate of two pictures from two fingers is 99. 8%,in the basic key extraction scheme the key extraction success rate of the same finger is 43. 7%,in the improved key extraction scheme the key extraction success rate of the same finger is 46. 3%.

Key words: Fingerprint key extraction,Image quality,Key recover success rate