Colour Fusion in Face Authentication System Based on Visible and Near Infrared Images

In this paper, face authentication using images taken in visible and near-infrared spectra (NIR) is studied. Visible images are in RGB colour space and near-infrared images are in gray levels colour space. First, the performance of system in each of the primary colour spaces of visible and near-infrared spectrum is evaluated that the verification process is based on the Normalised Correlation measure within the LDA feature space. In order to utilize the information of colour images, the scores associated to an adaptively selected subset of the colour based classifiers are then fused in the decision level. The selection process is based on a sequential search technique called the "plus L and take away R" algorithm. The sum rule and svm rule is used for fusing the related scores. Our extensive experimental studies using the HFB face database demonstrate that using the proposed method, the performance of the system considerably improves as compared to the individual Visible-based or NIR-based face verification systems

Optical Properties of NiO Columnar Nanostructure Prepared by OAD Technique

Abstract: NiO columnar nanostructure was prepared using the thermal evaporation technique with oblique angle deposition (OAD). The morphological, structural, and optical properties change with the creation of the substrate inclination. NiO columnar nanostructure was analyzed using X-ray diffraction (XRD) analysis and field emission scanning electron microscope (FESEM). The strain values ε obtained exhibit that the strain becomes tensile (ε>0) for (2 0 0) and (2 2 2) planes. Conversely, the strain returns to a compressive state (ε<0) for (1 1 1) and (2 2 0) planes. The average tensile strain in NiO columnar nanostructure is obtained at 1.4% while the average compressive strain is obtained at 2.04%. The value of the optical bandgap of the NiO columnar nanostructure is obtained at about 4.06 eV. The refractive index showed two absorption bands around the wavelengths of 520 nm and 700 nm with values of 2.19 and 2.22, respectively. Then, the refractive index increased from 2.22 at 700 nm to 2.35 at 920 nm and remained almost constant over 920 nm