A system and method of capturing an acceptable fingerprint image is disclosed
herein.
The method includes a step of capturing an initial fingerprint image at a nominal
image integration time. Once this initial fingerprint image is captured, a first
intermediate fingerprint image at a first intermediate image integration time is
captured. Next, an image darkness test is performed followed by an image definition
test. If one or more of these tests indicates that the first intermediate fingerprint
image is unacceptable, a subsequent intermediate fingerprint image at a subsequent
intermediate image integration time is captured. This subsequent intermediate fingerprint
image can be captured before the image definition test is performed. Additional
intermediate fingerprint images can be captured until an image that has an acceptable
darkness level as a well as an acceptable definition level is captured. Also disclosed
is a fingerprint scanner that performs this method.