基于DSP平台的数字视频源的系统设计

提出了一种基于TI DSK6711平台的将模拟视频进行数字化处理的系统设计方案,其中视频解码模块完成复合视频信号数字化,音频A／D模块完成语音信号数字化,同时采用大容量的SDRAM存储器作为帧缓存,用FPGA完成其控制接口,整个系统以DSK6711为核心构成数据处理单元,此系统可以完成电视图像信号的去隔行扫描转换、低分辨率向高分辨率转换等视频信号处理,也可以进行实时视频和音频数据压缩处理。     

Multifarious injection chamber for molecular structure study (MICOSS) system: development and application for serial femtosecond crystallography at Pohang Accelerator Laboratory X‐ray Free‐Electron Laser

The multifarious injection chamber for molecular structure study (MICOSS) experimental system has been developed at the Pohang Accelerator Laboratory X‐ray Free‐Electron Laser for conducting serial femtosecond crystallography. This system comprises several instruments such as a dedicated sample chamber, sample injectors, sample environment diagnostic system and detector stage for convenient distance manipulation. Serial femtosecond crystallography experiments of lysozyme crystals have been conducted successfully. The diffraction peaks have reached to ～1.8 Å resolution at the photon energy of 9.785 keV.     

基亏μC／OS-Ⅱ的高精度超声波测距系统设计

介绍一种以ARM处理器LPC2138为核心,采用超声波回波信号的A／D采样检测原理,实时测距,液晶屏显示的便携式系统。该系统利用ARM处理器处理速度快的优点,自行处理A／D采样速度。系统的测距范围在0．1-4．5m内,测量精度为1cm,实时性好,准确方便,有较高的推广价值。     

毫米波测云雷达回波信号衰减补偿仿真研究

针对毫米波测云雷达受云雨衰减的问题,从雷达I、Q信号角度出发,模拟毫米波测云雷达回波I、Q信号并假设一定的探测环境,进行雷达回波信号衰减补偿仿真试验.试验结果表明,雷达电磁波信号穿过雨区和云区时,在远距离处衰减量很大,通过衰减补偿,信号强度明显增强,目标信号突出.     

双包层EYDFA增益钳制效果的理论研究

基于速率方程的离散算法,实现了环形腔控制方案下,双包层EYDFA增益钳制的分析,研究了单、多信道情况下增益、噪声指数钳制的效果。结果表明：对于单信道EYDFA,随着衰减器衰减系数的增大,EYDFA的增益钳制范围增大,但信号增益钳制的幅度减小,且信号噪声指数增大;对于多信道EYDFA,只要激光谐振不被破坏,各信道增益都能得到有效钳制。     

数字视频采集回放系统的SoPC设计

介绍了一种基于SoPC技术的嵌入式数字视频图像采集控制模块的设计方案,通过在CycloneⅡFPGA上配置NiosⅡ软核处理器、ADV7181的I2C配置模块、视频图像采集模块、视频图像解码及颜色转换等相关接口模块来实现硬件平台,并利用Altera公司的软件集成开发环境NiosⅡIDE进行软件设计来控制整个采集流程.对...     

基于SVGA与PAL视频双接口嵌入式成像系统

本文介绍了一种基于SVGA显示接口和PAL制式视频接口两种显示接口的成像系统,两种显示接口共用同一块图像存贮器,能实现图像的动态实时显示.系统采用SOPC技术,将32位CPU、SVGA时序控制单元、PAL制视频控制单元及实时成像控制单元集成嵌入在一片FPGA芯片中.     

基于PowerPC+FPGA的视频处理器设计实现

介绍了一种基于PowerPC和FPGA构架的设计方案,阐述了图像处理硬件部分的组成的原理和结构,包括视频解码输入部分,后端的编码输出部分,以及在FPGA内的处理,主要是对图像进行了隔行转逐行、叠加和选择。同时给出了通信过程中的数据流流通过程和方式。设计的图像处理器可以实现初步转换视频制式和通信方式,并可实现叠加和切换。可以进一步处理实现PAL视频与VGA视频的转换。     

多媒体电视图文演播系统

介绍了多媒体电视图文演播系统的组成,包括电视图文信号的形成过程、电视图文信号与彩色PAL制式视频信号进行视频频率合成的硬件及多媒体电视图文演播系统软件。     

Synthetic high coding for the pal luminance signal

For the transmission of PAL TV signals, the data rate of the luminance signal should not exceed 3-3.4 bit/pel, and the quality should fulfil the TV signal transmission standard. We suggested a synthetic high coding combined with DPCM coding for the luminance signal to meet the requirement. A 1-D FIR filter is used for filtering out the low signals. The sampling rate of low signal is lowered by subsampling and the signals are then coded in the usual DPCM manner. The difference of the luminance signal of present picture element with its previous picture element, when it exceeds a threshold, is the edge signal. The edges are then separated into two kinds, the relevant edges and non-relevant edges, according to the masking effect of visual perception. Those edges that can be discarded, which can not be perceived visually when the reconstructed picture is compared with the original picture, are non-relevant edges. The relevant signals and their addresses are coded and called the high signal. We have obtained a coding rate of 3.3 bit/pel for the luminance signal. The quality of the coded picture is similar to an 8 bit/pel PCM picture by subjective test. The errors in different steps of the coding are discussed. The limitation of the method is also discussed.