New Dynamic Algorithm for IRFPA Bad Pixel Detection and Compensation Based on Statistics

Based on the analysis to the behavior of bad pixels, a statistics-based auto-detecting and compensation algorithm for bad pixels is proposed. The correcting process is divided into two stages： bad pixel detection and bad pixel compensation. The proposed detection algorithm is a combination of median filtering and statistic method. Single frame median filtering is used to locate approximate map, then statistic method and threshold value is used to get the accurate location map of bad pixels. When the bad pixel detection is done, neighboring pixel replacement algorithm is used to compensate them in real-time. The effectiveness of this approach is test- ed by applying it to I-IgCATe infrared video. Experiments on real infrared imaging sequences demonstrate that the proposed algorithm requires only a few frames to obtain high quality corrections. It is easy to combine with traditional static methods, update the pre-defined location map in real-time.

Design of compensation pixel circuit with In-Zn-O thin film transistor for active-matrix organic light-emitting diode 3D display

This paper presents a new compensation pixe] circuit suitable for active-matrix organic light-emitting diode （AMOLED） stereoscopic three dimensional （3D~ displays with shutter glasses. The simultaneous emissio~ method was used to solve the crosstalk problem, in which the periods of initialization and threshold voltage detectio11 occur for each pixel of whole panel simultaneously. Furthermore, there was no need of the periods of initialization and threshold voltage detection from the second frame beginning by one-time detection method. employing threshold voltage The non-uniformity of the proposed pixel circuit was considerably low with an average value of 8.6% measured from 20 discrete proposed pixel circuits integrated by In-Zn-O thin film transistors （IZO TFTs）. It was shown that the OLED current almost remains constant for the number of frames up to 70 even the threshold voltage detection period only exists in the first frame.

Centroids analysis for circle of confusion in reverse Hartmann test

The point spread function（PSF） is investigated in order to study the centroids algorithm in a reverse Hartmann test（RHT） system. Instead of the diffractive Airy disk in previous researches, the intensity of PSF behaves as a circle of confusion（CoC） and is evaluated in terms of the Lommel function in this paper. The fitting of a single spot with the Gaussian profile to identify its centroid forms the basis of the proposed centroid algorithm. In the implementation process, gray compensation is performed to obtain an intensity distribution in the form of a two-dimensional（2D） Gauss function while the center of the peak is derived as a centroid value. The segmental fringe is also fitted row by row with the one-dimensional（1D） Gauss function and reconstituted by averaged parameter values. The condition used for the proposed method is determined by the strength of linear dependence evaluated by Pearson＇s correlation coefficient between profiles of Airy disk and CoC. The accuracies of CoC fitting and centroid computation are theoretically and experimentally demonstrated by simulation and RHTs. The simulation results show that when the correlation coefficient value is more than 0.9999, the proposed centroid algorithm reduces the root-mean-square error（RMSE） by nearly one order of magnitude, thus achieving an accuracy of - 0.01 pixel or better performance in experiment. In addition, the 2D and 1D Gaussian fittings for the segmental fringe achieve almost the same centroid results, which further confirm the feasibility and advantage of the theory and method.

VCSEL-pumped Nd：YAG laser with 95W average power and user-selectable nanosecond pulses

A 95 W Nd：YAG laser system pumped by a vertical cavity surface emitting laser（VCSEL） array is described.The laser contains an all-fiber-based seeder, an Nd：YAG regenerative amplifier, and a four-pass amplifier. The laser operates at 300 Hz with energies up to 317 m J. The beam has a top-hat intensity distribution. The temporal pulse shape is flat in time, and the pulse width can be adjusted in the range of 2–6 ns.