Fingerprint Image Contrast Research Articles

Optical Waveguide Fingerprint Recognition Device with Two‐Stage Dual‐Function Gratings (Adv. Mater. Interfaces 10/2023)

Optical Fingerprint Recognition In article number 2202361, Weiqiang Lin, Peijin Wu, Zhicheng Ye, and colleagues delicately assembled a series of cooperative sub-wavelength gratings acting as an efficient and ultra-thin light controlling interface based on flexible substrates, by which, the incident beam is sent to the sensing zone via consecutive trapping, splitting, redirecting, and expanding processes. The contrast of fingerprint images is enhanced 11-fold.

A Fingerprint-Based Verification Framework Using Harris and SURF Feature Detection Algorithms

Amongst all biometric-based personal authentication systems, a fingerprint that gives each person a unique identity is the most commonly used parameter for personal identification. In this paper, we present an automatic fingerprint-based authentication framework by means of fingerprint enhancement, feature extraction, and matching techniques. Initially, a variant of adaptive histogram equalization called CLAHE (contrast limited adaptive histogram equalization) along with a combination of FFT (fast Fourier transform), and Gabor filters are applied to enhance the contrast of fingerprint images. The fingerprint is then authenticated by picking a small amount of information from some local interest points called minutiae point features. These features are extracted from the thinned binary fingerprint image with a hybrid combination of Harris and SURF feature detectors to render significantly improved detection results. For fingerprint matching, the Euclidean distance between the corresponding Harris-SURF feature vectors of two feature points is used as a feature matching similarity measure of two fingerprint images. Moreover, an iterative algorithm called RANSAC (RANdom SAmple Consensus) is applied for fine matching and to automatically eliminate false matches and incorrect match points. Quantitative experimental results achieved on FVC2002 DB1 and FVC2000 DB1 public domain fingerprint databases demonstrate the good performance and feasibility of the proposed framework in terms of achieving average recognition rates of 95% and 92.5% for FVC2002 DB1 and FVC2000 DB1 databases, respectively.

Analysis of the Influence of Non-Directional Algorithms on Fingerprint Image Enhancement

Fingerprint image enhancement is of key importance for the efficiency of the automated fingerprint identification system. Before we can enhance a fingerprint image with contextual filters, we need to enhance fingerprint image contrast and readability with non-directional filters. This article provides an analysis of the influence of non-directional image enhancement techniques in the fingerprint image pre-processing step. To perform the analysis we used global normalization algorithm, local normalization algorithm, Wiener filter, histogram equalization algorithm and median filter. To evaluate the equal error rate in the experiments, done on a public database FVC_2004, we used Gabor filter and a state-of-the-art two-stage algorithm. DOI: http://dx.doi.org/10.5755/j01.eee.20.6.7277

Fluorescence optimisation and lifetime studies of fingerprints treated with magnetic powders

Fluorescence study plays a significant role in fingerprint detection when conventional chemical enhancement methods fail. The basic properties of fluorescence emission such as colour, intensity and lifetime could be well exploited in the detection of latent fingerprints under steady state and in dynamic methods. This paper describes a systematic study of fluorescence emission intensity from fingerprint samples treated with different magnetic powders. Understanding of suitable excitation wavelength required for getting maximum fluorescence emission intensity could be beneficial when selecting the appropriate fluorescent powders for the fingerprint detection. Lifetime study of fingerprints treated with various magnetic powders was also carried out. The importance of lifetime study is well explained through the time-resolved (TR) imaging of fingerprints with nanosecond resolution. Results from the TR imaging study revealed an improvement in the fingerprint image contrast. This is significant when the print is deposited on fluorescing background and its emission wavelength is close to that of treated fingerprint.