Abstract:Infrared polarization imaging can use the difference of objects in the degree of polarization to detect the targets against the complex background. In the battlefield, because the man-made and natural objects have a difference in the degree of polarization, the use of infrared polarization imaging can improve one's ability to distinguish the camouflage from the nature. Firstly, the theory of polarization imaging and its system components are presented. Then, the target feature extraction based on the polarization image processing is analyzed. The polarization image quality evaluation, image fusion, image segmentation and feature extraction methods are studied. Finally, the applications based on infrared polarization imaging at abroad are given and the value of this technology to military applications is pointed out.

Abstract:The Hyper Spectral Imager (HSI) onboard the HJ-1A satellite has acquired a large quantity of image data since its launch in Sep. 2008. However, the effectiveness of those images is greatly limited because of the apparent stripe noise in the images acquired in partial bands of the HIS. According to the features of the image noise, a new method for removing the stripe noise by moving the windows based on a reference band is proposed. The result shows that this new noise removing algorithm can not only remove the stripe noise in the images effectively and improve the definition of the images remarkably, but also can retain the basic information of the raw images. The method has the advantages of fast processing and wide range of application. It is an ideal stripe noise removing method.

Abstract:With the development of sensor technologies, a single image sensor can not extract enough information from a scene. So, the multi-source image fusion is urgent to be studied. To solve the problem that the features of a same object in the images from multiple sensors are not identical, the wavelet transform is used to fuse the infrared and visible images. Firstly, the wavelet transform is used to decompose the image in multi scale. For high frequency fusion, the coefficients with maximum absolute values in two original images are selected. For low frequency fusion, the strategy of combining the domain pixel correlation with the regional variance is used. The experimental result shows that this fusion algorithm can fuse the different features and details of a same object in infrared and visible images into one image. It can increase the information in one image and enrich the information hierarchy of the target. It provides the basis for the image display and subsequent image processing.

Abstract:According to the characteristics of human visual systems, an algorithm for enhancing the salient objects in color fusion of night vision images based on spectral residual is proposed. In the color fusion process, the range of the salient object is determined by the spectral residual and the salient object is located with a window of 5?5 pixels. When the mean value in this window is greater than the global mean value, the pixels are located on the salient object. Then, the salient object is highlighted in red color so as to enhance the color fusion image. The experimental result shows that the new algorithm is stable and practical and is more effective in the enhancement of salient objects.

Abstract:According to the minimum resolvable contrast criterion, the method for calculating the maximum detection range of an airborne infrared imaging system to a target in a background environment is studied. The infrared radiation characteristics of the infrared target in two wavebands of 3 to 5 μm and 8 to 14 μm and the influence of background radiation and atmospheric transmittance etc on the detection range are analyzed. The derivative formula of the detection range is given. Finally, the atmospheric transmittance is simulated with the MODTRAN. The atmospheric spectral transmission data with a wave number interval of 1 cm_-1 is obtained. The irradiance on the detector in each mini wavelength region is calculated. By taking the relationship between the atmospheric transmittance and the distance, the replacement of atmospheric transmittance by constant or fitting function in the traditional algorithm is canceled. Taking the cruise missile as an example, the detection range of an infrared system is calculated numerically. The simulation result shows that this calculation method is feasible.

Abstract:A near-infrared emitting natural sodalite was fabricated by using a high temperature solid state reaction method. The X-ray diffraction (XRD) of the fluorescent powder and its near-infrared emission spectrum and excitation spectrum at room temperature were determined. Excited by the visible light at the wavelength of 600 nm, the Mn⁵ ion (³A₂-¹E transition) in the natural sodalite powder emitted the near-infrared spectrum which had its main emission peak at the wavelength of 1200 nm. At the excitation of the visible light at the wavelength of 500 nm, the Fe² ion (³T₁-⁵E) in the powder emitted the near-infrared spectrum which had its main emission peak at the wavelength of 1000 nm. The finding of this phenomenon was of positive significance to the improvement of the efficiency of silicon solar cells.

Abstract:The isolated tissue samples are illuminated by using the LED radiation sources at different wavelengths. Then, the ray transmitted through the tissue samples is received by using a spectrometer. The waveform and wavelength distribution of the ray transmitted through the tissue samples from the LEDs are compared. The frequency spectra of the ray transmitted through the same tissues at different frequencies is analyzed. Finally, the optimal wavelength range for the LEDs to transmit the tissues is obtained. This result is instructive to the application of the LED radiation sources to therapy products.