Patent ID: 7251372
Filing Date: 2007-07-31
Classification: G06K,H04N

Abstract:
1. A method for achieving a desired value for the magnitude of compression when compressing the information contained in a digitized fingerprint image using a lossy compression method that includes use of a compression parameter whose value may be varied to adjust the amount of compression actually achieved, the method comprising: selecting a first value for the compression parameter; performing a first compression of the information contained in a digitized fingerprint image using the first value for the compression parameter and using the lossy compression method, thereby producing a first set of compressed information; computing a first value for the magnitude of compression from the quantity of information contained in the digitized fingerprint image and the quantity of information contained in the first set of compressed information; forming a first pair of values which first pair includes the first value for the magnitude of compression and the first value for the compression parameter; interpolating, using the first pair of values, a second pair of values, and a first new pair of values which first new pair includes the desired value for the magnitude of compression and an as yet unknown first new value for the compression parameter to determine a value for this first new value for the compression parameter by computing its value from the remaining five values; and performing a first new compression of the fingerprint image information using this first new value for the compression parameter to produce a first new set of compressed information; whereby the first new set of compressed information is compressed close to the desired value for the magnitude of compression.