光谱学与光谱分析, 2012, 32 (6): 1700, 网络出版: 2012-06-14
ADV212在大视场多光谱TDICCD空间相机中的应用
Application of ADV212 to the Large Field of View Multi-Spectral TDICCD Space Camera
多光谱空间相机 ADV212压缩系统 Custom-specific模式 图像帧 中断处理策略 Multi-spectral space camera ADV212 compression system Custom-specific mode Image frame Interrupt processing strategy
摘要
针对空间多光谱相机中CCD输出数据量大、 谱段间冗余小和行频可变等导致常见基于矢量量化、 预测和变换编码的整体压缩方案硬件实现困难的问题, 提出了一种基于ADV212的空间相机图像压缩方案。 依据ADV212工作原理和CCD图像特点, 提出了Custom-specific工作模式, 在该模式下, 使用提出的图像帧和中断处理策略, 并以流水线作业的方式实现单片ADV212处理8通道CCD图像; 分析了影响图像压缩质量的2个参数, 提出了(10, 5)量化步长设置方法, 使码率控制误差减小了16.385%; 使用地检设备对ADV212压缩系统进行了试验验证。 结果表明, 压缩系统能快速稳定地工作, 在压缩比指标2∶1~32∶1内, PSNR均在30 dB以上, 与传统方法相比, 在正常工作压缩比为1 bpp时平均PSNR提高了2.49 dB。 有效的解决了整体压缩方案硬件实现困难的问题。
Abstract
In order to resolve the difficult to hardware implementation of the whole vector quantization-based, predictive coding-based and transform coding-based compression scheme caused by the large volume of data, small spectral redundancy and line frequency variability etc. in multi-spectral space camera, an image compression scheme based on ADV212 was proposed in space camera. Firstly, custom-specific mode was presented based on the working principle of adv212 and CCD image properties. In the Custom-specific mode, an ADV212 is able to compress 8 channel CCD data by proposed image frame and interrupt processing strategy using pipelining. Then, this paper analyses the two parameters which affect the quality of image compression. A (10, 5) setting the quantization step method was proposed. This method makes the rate control error reduces 16.385%. Finally, the verification experiments to ADV212 compression system using ground test equipment were carried out. The experiments results showed that compression system can be fast and stable work. All PSNR were more than 30dB in the compression ratio of 2∶1 to 32∶1. Compared with traditional approaches, the proposed method could improve the average PSNR by 2.49 dB in the lossy compression mode when the compression ratio is 1bpp. They effectively solve the difficult of hardware implementation of the whole wavelet-based compression scheme.
李进, 金龙旭, 李国宁, 张柯, 王文华. ADV212在大视场多光谱TDICCD空间相机中的应用[J]. 光谱学与光谱分析, 2012, 32(6): 1700. LI Jin, JIN Long-xu, LI Guo-ning, ZHANG Ke, WANG Wen-hua. Application of ADV212 to the Large Field of View Multi-Spectral TDICCD Space Camera[J]. Spectroscopy and Spectral Analysis, 2012, 32(6): 1700.