摘要
为了从单CCD/CMOS图像探测器相机拍摄的Bayer格式图像恢复出更高分辨率全彩色图像,设计了一种改进的联合去马赛克与放大算法。首先,估计原始Bayer格式图像中丢失的绿色通道信息,根据颜色梯度的比较结果,将水平或垂直方向的绿色通道信息作为彩色图像的G分量,并根据彩色图像颜色通道之间高度相关的特性,计算颜色差R-G和B-G;然后,将去马赛克过程中的梯度方法继续用于确定丢失的绿色像素,放大绿色通道;最后,对颜色差值图像R-G和B-G进行放大,即可恢复出红色和蓝色通道信息,得到放大的全彩色图像。试验结果表明,算法恢复出的高分辨率彩色图像的峰值信噪比(PSNR)有较明显提升,且主观目视清晰、边缘锐利,特别是硬件实现方面能够做到实时处理。目前,本文算法已经在Xilinx公司的FPGA上实现,并用于工程实践。满足了项目实际需要。
In order to obtain higher resolution full color image from Bayer CFA structure image directly,this paper presents a new joint demosaicking and zooming algorithm for digital camera equipped with a single CCD/CMOS sensor.We firstly extract GH and GV components of each pixel from m osaicking image through horizontal and vertical interpolations,respectively,and then we calculate and compare the hori zontal chrominance gradient and the vertical one for choosing the missing G from GH and GV.By exploiting the hig h spectral-spatial correlations between color channels,we compute the two color difference images R-G and B-G to reduce the demosaicking and zooming errors.Next,we obtain the horizontal GzoomH and vertical G zoomV of each pixel,and also choose the missing zoomed Gzoom by calculating and comparing the chrominance gradient .Finally,the enlarged red and blue channels are obtained by adding the corresponding enlarged R-G and B-G color d ifference images to the enlarged green channel.Experimental results prove that the proposed algorithm outperfor ms some state-of-the-art demosaicking-zooming methods in both peak signal-to-noise ratio （PSNR） measur e and visual quality.Furthermore,computational cost of the algorithm is low and it can be hardware processed in real time.Now,the proposed a lgorithm is implemented on Xilinx FPGA and used in camera system,and the perfect restoration quality and ef fectiveness meet the requirement of system design.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2014年第1期199-206,共8页
Journal of Optoelectronics·Laser
基金
国家自然科学基金重点项目(90920301,61231018)
陕西省教育厅科研计划(2013JK1057)资助项目
