Wu Xiaolin, Zhang Lei
Department of Electrical and Computer Engineering, McMaster University, Hamilton, Canada.
IEEE Trans Image Process. 2006 Oct;15(10):3138-51. doi: 10.1109/tip.2006.877504.
Color demosaicking is critical to the image quality of digital still and video cameras that use a single-sensor array. Limited by the mosaic sampling pattern of the color filter array (CFA), color artifacts may occur in a demosaicked image in areas of high-frequency and/or sharp color transition structures. However, a color digital video camera captures a sequence of mosaic images and the temporal dimension of the color signals provides a rich source of information about the scene via camera and object motions. This paper proposes an inter-frame demosaicking approach to take advantage of all three forms of pixel correlations: spatial, spectral, and temporal. By motion estimation and statistical data fusion between adjacent mosaic frames, the new approach can remove much of the color artifacts that survive intra-frame demosaicking and also improve tone reproduction accuracy. Empirical results show that the proposed inter-frame demosaicking approach consistently outperforms its intra-frame counterparts both in peak signal-to-noise measure and subjective visual quality.
对于使用单传感器阵列的数码照相机和摄像机而言,颜色去马赛克处理对于图像质量至关重要。受彩色滤光片阵列(CFA)的马赛克采样模式限制,在去马赛克处理后的图像中,高频和/或鲜明颜色过渡结构区域可能会出现颜色伪像。然而,彩色数码摄像机捕捉一系列马赛克图像,并且颜色信号的时间维度通过摄像机和物体运动提供了有关场景的丰富信息源。本文提出一种帧间去马赛克处理方法,以利用像素相关性的所有三种形式:空间相关性、光谱相关性和时间相关性。通过运动估计以及相邻马赛克帧之间的统计数据融合,新方法可以去除帧内去马赛克处理后残留的许多颜色伪像,并且还能提高色调再现精度。实验结果表明,所提出的帧间去马赛克处理方法在峰值信噪比测量和主观视觉质量方面均始终优于其帧内对应方法。