Research On The Information Fusion Technology Of Range-Gated Active And Passive Image

Range-gated imaging technology is an active imaging technology, using a certain wavelength as a carrier to deliver information, and it can achieve not only the three-dimensional spatial information with high resolution but also can achieve the real-time detection of target. The main devices of range-gated imaging system are the pulse laser and high performance ICCD camera, and this system can not only active imaging when emitting laser, but also can use the natural light to get the passive image when the laser is not emitted. These two kinds of images have different characteristics, information complementation, so the image fusion can improve target recognition ability. Based on wavelet transform, the fusion of range-gated active and passive images is studied in this thesis.Firstly, investigated the progress in the fusion of active and passive images both in domestic and foreign, research on the theory of image fusion based on wavelet transformation, the range-gated laser imaging technology and its image features.Secondly, according to the proposed simulation image fusion scheme, the range-gated simulation active and passive image is carried out based on the wavelet transformation. In the preprocessing, the noise is eliminated with the gradient inverse weighted smoothing method and threshold value filtering. Then the selection of optimal wavelet and decomposition layers is discussed and the results are evaluated.Finally, conducted the range-gated active and passive image acquisition experiments and in the image fusion experiment of active image and optical passive image, an improved mean value algorithm is proposed for low frequency coefficients.Experimental results show that the proposed method can largely suppress the influence of the target background on image fusion quality. According to the method of simulation experiment, confirmed the optimal wavelet is sym5 and the wavelet decomposition level is two layers, obtained the fused image and then fused with range image. The experimental results show that the information fusion of the range-gated active and passive image improves the information quantity and the definition of the intensity image, enhance the edge and improve the recognition ability of the target.