Fingerprint Image Preprocessing Based on Whole-Hand Image Captured by Digital Camera

There are many biometric features in the hand images captured by digital camera, but few studies are done to extract fingerprint image from it. This paper presents some fingerprint image preprocessing approaches based on a whole-hand image captured by digital camera. The preprocessing methods include key point location, finger image segmentation and fingerprint region extraction. Firstly, the key points including fingertips and valley points, which are called key points, are located from the hand contour image. Secondly, the middle finger is cropped from the hand image based on the information of the key points' positions and the knuckle's texture near the finger root. Finally, the fingerprint is extracted from the middle finger through the first knuckle's texture. Because of the low resolution of the fingerprint images, linear projection methods such as Principle Component Analysis (PCA) and Linear Discriminant Analysis (LDA) are used for fingerprint feature extraction. Experimental results on a database of 86 hands (10 impressions per hand) show that these approaches are effective.