摘要
介绍了一种胶囊型内窥镜中视频图像数据源记录系统的工作原理和设计方案。该系统以TI公司的高性能数字信号处理器(Digital signal processor,DSP)TMS320C6211为核心处理器,采用PHILIP公司视频解码器SAA7114H对模拟视频信号进行数据缩放,在复杂可编程逻辑控制电路(Complex programmable logic device,CPLD)的控制下,视频图像数据由高速缓存先入先出队列(Fist-in First-out,FIFO)传输到DSP进行静止影像数字压缩通用标准格式(JPEG)压缩,最后将处理后的图像数据存入高密度闪存(Compact flash,CF)卡,完成视频图像的及时记录功能。其中DSP主要用来进行压缩编码和数据传输,我们采用离散余弦算法(Discrete cosine transform,DCT)和DCT系数量化的快速算法加快了DSP的运算速度,减少了DSP的执行代码,同时我们对各种存储类型进行了合理的分配,优化了存储器结构。在数据传输和处理过程中大量使用扩展的直接存储器访问(Extended directmemory access,EDMA)来加快处理数据的速度并提高了系统的性能。
A video image recorder to record video picture for wireless capsule endoscopes was designed. TMS320C6211 DSP of Texas Instruments Inc. is the core processor of this system. Images are periodically acquired from Composite Video Broadcast Signal （CVBS） source and sealed by video decoder （SAA7114H）. Video dam is transported from high speed buffer First-in First-out （FIFO} to Digital Signal Processor （DSP） under the control of Complex Pro- grammable Logic Device （CPLD）. This paper adopts JPEG algorithm for image coding, and the eornpressed data in DSP was stored to Compact Flash （CF） card. TMS320C6211 DSP is mainly used for image eornpression and data transporting. Fast Discrete Cosine Transform （DCT） algorithm and fast coefficient quantization algorithm are used to accelerate operation speed of DSP and decrease the executing code. At the same time, proper address is assigned for each memory, which has different speed;the mernory structure is also optimized. In addition, this system uses plenty of Extended Direct Memory Access （EDMA） to transport and process image data, which results in stable and high pedormanee.
出处
《生物医学工程学杂志》
EI
CAS
CSCD
北大核心
2008年第1期7-11,共5页
Journal of Biomedical Engineering
基金
国家863计划资助项目(2004AA404012)
重庆市科委资助项目(7933)
