The Research Of Automatic Fingerprint Identification System Algorithm

More and more people pay attention to Biology identification technology for the security and convenience reason. Fingerprint recognition is the most important application of it. That is because that it is easy to get the fingerprint of someone you want and there is no same fingerprint in the world. Based on computer and live fingerprint scanner, using technology image processing and pattern recognition, this study investigates theory and methods of automatic fingerprint identification, implements algorithms of automatic fingerprint identification system(AFIS). The thesis is organized as follows. Chapter 1 is introduction. Chapter 2 is presents design of the automatic fingerprint identification system and related issues. Chapter 3 discusses fingerprint feature extraction and a new minutiae algorithm based on imperfect thinning fingerprint image. Chapter 4 deals with a minutiae matching algorithm based on point pattern matching. The last Chapter is conchision. The main contents are as follow:1 The method to segment fingerprint from background are studied. By selecting threshold which makes the number of pixels that are bigger than the threshold equal to the number of pixels that are smaller than it for local area. ,fingerprint image can be self-adaptively segmented from the background. After that we can make sure the final result through the information around the local area.2 The method of ridge extraction is studied. Using the orientation information of local area, masks for smoothing and enhancing are designed respectively. These masks can smooth the image along orientation of the ridges and enhance the image along orientation orthogonal to ridges at the same time. Results indicate that the method can connect breaks of the ridges and can dispart conglutinated ridges. As a result, the ridges that are single color are extracted correctly.3 After get the minutiaes from thinning ridges, erase some minutiaes that are not real minutiaes using several regulars.4 Improve the point pattern matching method to reduce the spending on time.This study systemically investigates theory and methods of automatic fingerprint identification, bring a new idea in acquiring minutiae extraction with accuracy.This study will be helpful for the people who relate with AFIS.