In this paper, a modified 3D computational reconstruction method in the compressive 4D-spectro-volumetric snapshot imaging system is proposed for better sensing spectral information of 3D objects. In the design of the imaging system, a microlens array (MLA) is used to obtain a set of multi-view elemental images (EIs) of the 3D scenes. Then, these elemental images with one dimensional spectral information and different perspectives are captured by the coded aperture snapshot spectral imager (CASSI) which can sense the spectral data cube onto a compressive 2D measurement image. Finally, the depth images of 3D objects at arbitrary depths, like a focal stack, are computed by inversely mapping the elemental images according to geometrical optics. With the spectral estimation algorithm, the spectral information of 3D objects is also reconstructed. Using a shifted translation matrix, the contrast of the reconstruction result is further enhanced. Numerical simulation results verify the performance of the proposed method. The system can obtain both 3D spatial information and spectral data on 3D objects using only one single snapshot, which is valuable in the agricultural harvesting robots and other 3D dynamic scenes.
An extraction method of edge features from 3D laser point cloud based on corresponding images was proposed. After the registration of point cloud and corresponding image, the sub-pixel edge can be extracted from the image using gray moment algorithm. Then project the sub-pixel edge to the point cloud in fitting scan-lines. At last the edge features were achieved by linking the crossing points. The experimental results demonstrate that the method guarantees accurate fine extraction.
ZnS thin films were prepared on HgCdTe substrates by thermal evaporation and megnetron sputtering deposition technique. The morphology, structure, composition, and optical properties of two kinds of ZnS thin films were studied by scanning electron microscope(SEM), X-ray diffraction(XRD), energy dispersive X-ray analysis(EDX) and fourier transform infrared(FTIR) spectrometer. Then the HgCdTe MIS devices using ZnS thin film as insulating layer were successfully fabricated. The C-V measurement of MIS devices was used to study electrical characteristics of the ZnS/HgCdTe interface. The experimental results show that, the ZnS thin films by thermal evaporation and megnetron sputtering both have good transmission characteristics in infrared waveband and close atomic ratios of Zn/S. The former one exhibits zincblende structure and a phenomenon of layer growth, but the latter one exhibits wurtzite structure and an obvious phenomenon of island growth. It is also found that, the former one has less fixed charge density than the latter one.
Proc. SPIE. 8768, International Conference on Graphic and Image Processing (ICGIP 2012)
KEYWORDS: Signal to noise ratio, Statistical analysis, Error analysis, Estimation theory, Interference (communication), Receivers, Monte Carlo methods, Signal processing, Electronic filtering, Information security
A blind parameters estimation algorithm based on forward difference of power spectral density is presented to solve the problems in co-channel multiple signals processing. The proposed algorithm can fast and accurately estimate such parameters as number of signals, center frequency, signal power, noise power and signal to noise ratio of the mixed signals. Both theoretical analysis and simulation results show that the algorithm is effective.
In this paper, we study the magneto-transport properties of ion-etching-induced p-to-n type converted layers in Hg<sub>1</sub>-
<sub>x</sub>Cd<sub>x</sub>Te (x=0.24) single crystal with the help of mobility spectrum analysis (MSA) technique. Hall measurement shows
that the residual p-HgCdTe completely converted to n-type after ion etching. By step-by-step chemical etching, MSA
reveals that ion-etching-induced conversion results in a damaged surface layer with low electron mobility while a bulk n-type
region exhibits higher electron mobility. It can be observed that the mobility of the surface electrons is
independence of temperature in the measured temperature range. In contrast, the bulk electrons exhibit classical behavior
of n-HgCdTe with characteristics that are strongly dependence on temperature. The Hall data from different thickness
shows the bulk n-layer is uniform with high mobility and lower concentration.