一种适合数字相机实时处理的插值算法

An Interpolation Algorithm for Real Time Processing of Digital Cameras

为保证图像还原质量的情况下实现数字相机实时处理的功能,提出了一种基于梯度的单通道独立插值算法。通过引入绿色分量的水平、垂直梯度及梯度差值的阈值不仅可以使图像的边界信息得到更好的保存,也可以使平滑区域的色彩更加平滑。同时引入红色、蓝色分量的斜45°、斜135°方向的梯度作为边界判定的补充,保证三种颜色通道的边界都能得到有效判断,使整个图像边界变得更清晰。为验证算法的插值效果,采用Matlab进行仿真测试。仿真表明:该插值算法在平滑区和边界都能得到较理想的效果,相对最近邻插值和双线性插值边界,拉链现象明显降低。理论分析表明:该算法避免了复杂的乘除运算,易于硬件实现,且适宜于并行处理。

In order to ensure the reconstruction quality of an image and realize the function of real time processing, a single channel interpolation algorithm based on gradient is proposed. By introducing horizontal and vertical gradient of the Green channel, the edge information can be preserved better, and the color of the smooth area becomes more smooth simultaneously. And by simultaneously introducing the 45° and 135°gradients of the Blue and Red channels as the additional edge judgement, the edge information of all the three channels can get a sufficient judgement, so the edge of the whole image become more clearer. Then, the quality of the interpolation algorithm will be evaluated and verified by the Matlab simulation. The experimental results show that, compared with Nearest Neighbor Replication and Bilinear interpolation, a better quality can be got not only on edge but in the smooth area, and the zipper effect is reduced apparently. Theoretical analysis indicates that the proposed algorithm is easy to realize for hardware without complicated multiplication and division operation, and the procedure of the interpolation is suitable for parallel processing.