An effective fingerprint orientation field estimation method using differential values of grayscale intensity.

Fingerprint orientation field (OF) estimation is important for basic fingerprint image processing and impacts the accuracy of fingerprint image enhancements, such as Gabor filters. In this article, we introduce an OF estimation algorithm based on differential values of grayscale intensity and examine the accuracy and reliability of the proposed algorithm by applying it to fingerprint images processed using Gaussian blurring and the Gaussian white noise process. The experimental results indicate that the OF estimation reliability of the proposed algorithm is higher than the gradient-based method and the power spectral density (PSD) based method in low quality fingerprints.

The Enhanced Thermal Stability of (MgNi)TiO Dielectric Ceramics Modified by a Multi-Phase Method.

The thermal stability of (MgNi)TiO dielectric ceramics has been improved by mixing with CaTiO phases owing to higher positive temperature coefficients. The pure (MgNi)TiO and the mixture phase systems of CaTiO-modified (MgNi)TiO were verified by XRD diffraction patterns to ensure the crystallite of different phases. The microstructures of the CaTiO-modified (MgNi)TiO were observed by SEM and EDS to investigate the relation between element ratios and grains.