CFA图像实时插值在FPGA上的应用

Application of CFA Images Interpolation Algorithm in FPGA Real-Time System

彩色滤波阵列(CFA)格式的图像需要进行图像插值,才能获得全彩色图像。但是,对CFA图像进行色彩还原选用算法越复杂,插值产生的图像质量越高,但复杂的算法,较长的处理时间不便于硬件实现,为实时处理带来不便。文章介绍了双线性插值法和边缘定向插值法两种色彩还原算法,并用硬件平台FPGA实现了双线性插值方法和基于边缘定向的方法,并用黑白条纹图对两种还原方法进行了比较分析,基于边缘定向的插值方法考虑了边缘的方向,防止跨越边界插值,因此插值效果优于双线性插值法,虽然算法复杂一些,但是合理设计FPGA的缓存模块,采用并行流水的处理方式,完全满足工程对实时性的要求。

The color filter array （ CFA ） format image needs to interpolation to obtain the full color image. However, the interpolation algorithm of the CFA image is more complex, the image quality is higher, but the complexity algorithm will take more time to implementa- tion, and it is inconvenient for real-time processing. This paper introduces two interpolation algorithm, the bilinear interpolation and edge oriented interpolation, and uses the FPGA hardware platform to realize the bilinear interpolation algorithm and the edge orientation algorithm, and analyzes two kind of algorithm with black and white stripes image. Conside- ring the edge direction, the edge oriented interpolation algorithm prevents the border interpolation, so the interpolation effect is better than that of the bilinear interpolation algo- rithm. Although the algorithm is some more complex, the optimized design of FPGA cache module, using parallel and pipiline processing mode, will fully meet the real-time require- ments of engineering.