视频卫星影像的Bayer插值重建

Bayer interpolation for video satellite images

视频卫星在成像过程中一般采用Bayer模板,地面处理时需要通过Bayer插值处理才可恢复全彩色的影像。针对视频卫星影像Bayer插值重建中容易出现拉链、噪点和边缘伪彩色等问题,提出一种改进的基于亮度、色度信号重建的滤波方法。首先,通过24张标准柯达影像训练得出Bayer插值重建的带通滤波器;其次,通过带通滤波器提取色度信号,并根据Bayer模型获取初始的重建结果;然后,在绿色空间中,利用梯度信息进行均值区域判断,并在均值和非均值区域中分别进行边缘方向插值和色差域中值滤波更新,有效减少均值区域的插值拉链和噪点现象;最后,在新的色差域中进行红光、蓝光波段的导向插值和中值滤波更新,进一步提升插值精度。采用吉林一号01星和03星的4幅视频影像数据验证本文方法的有效性,结果表明与2种经典的Bayer插值方法相比,提出的改进方法在定性和定量评价上均最优,影像边缘更加锐利、清晰,无明显噪点和伪彩色现象,可用于卫星视频数据的后续处理和应用。

Video satellite capture color video data are obtained by using the single CMOS sensor with color filter array (CFA) Bayer pattern.To obtain the full color image sequences,researchers should perform the processing of Bayer image interpolation.Aimed at the interpolation of satellite video Bayer image,the authors propose a improved method based on the signal filter reconstruction of luminance and chrominance.Firstly,band-pass filters are used for extracting luminance and chrominance signal.And the initial reconstruction result can be obtained according to the Bayer spatial model.Moreover,median filtering in non-smooth region and edge direction interpolation in the smooth region are applied to the G-B or G-R difference band for updating the green band.In the end,the red band and blue band are also updated in the new G-B or G-R difference band.To verify the feasibility of the proposed method,the authors tested 4 video Bayer image of Jilin-1 01 and 03 and compared the obtained results with two classic methods.The experimental results show that method designed by the authors has the best comprehensive performance both in subjective evaluation and objective evaluation.The reconstructed image quality is good and has no obvious noise and pseudo-color effects;in addition,the edge is sharp and clear.The method can be used for satellite video further processing and application.