一种被动矩阵OLED的混合控制驱动方法

本文介绍一种用于实现被动有机发光二极管矩阵(PM-OLED)高灰度显示的混合驱动方法.该方法基于电流型数模转换器和时空数字调制方法的混合驱动来实现整体屏幕的显示驱动.在该方法中,显示数据的低灰度权值由数模转换器完成调制,同时显示数据的高灰度权值由时空数字调制方法进行调制.该方法应用于128×128彩色PM-OLED可以驱动512级灰度显示.     

基于运动信息的液剂可见异物自适应分割算法

允动异物分钊是实现液剂可见异物自动检测的关键。提出一种基于帧差图空间方差和方差梯度的液剂异物 模糊自适应阂值分割算法。首先将2幅帧差图分为J X J的块,计算2幅帧差图对应块间的空间方差和方差梯度,并 以两者的乘积构成新特征图;然后使用自适应闰值完成运动异物的分割,为使阂值能够跟随块灰度变化,阂值的调整 采用模糊推理,依据方差和方差梯度变化自适应实现。实验及实际测试结果表明,所提算法能够满足低对比度和局部 光照变化的液剂异物实时检测要求,是一种实用有效的图像分割方法。     

液剂视频序列中运动异物的模糊自适应分割

运动异物的正确分割是实现液剂自动检测的关键.提出一种基于帧差图空间方差和方差梯度的液剂异物模糊自适应阈值分割算法.首先将4帧序列图像差分得到的2幅帧差图分为5×5的图像块,计算2幅帧差图对应图像块间的方差和方差梯度,并以两者的乘积构成新特征图;然后使用自适应阈值对新特征图进行运动异物分割和提取.为使阈值能够跟随图像块灰度变化,阈值的调整采用模糊推理依据方差和方差梯度变化自适应实现.实验及实际测试结果表明,该算法能够满足低对比度和局部光照变化的液剂异物实时检测要求,是一种实用有效的图像分割算法.     

基于Q-学习算法的矿井自适应OFDM调制研究

针对传统基于固定信噪比门限的自适应OFDM(正交频分复用)调制技术应用于复杂矿井信道时,由于反馈信道状态与实际信道状态不能完全匹配,导致误码率高和吞吐量低的问题,提出了一种基于Q-学习算法的自适应OFDM调制方法,并将其应用于矿井自适应OFDM调制系统。该系统由发送端、矿井无线信道和接收端组成,发送端为矿井下装有传感器的小车,可以在狭长的巷道内自由移动。发送端利用Q-学习算法在与矿井无线信道的动态交互中不断更新状态-动作值函数,并根据更新的状态-动作值函数,采用贪婪策略来选择调制方式,逼近最优自适应调制策略,以达到降低系统误码率、提高通信吞吐量的目的。与基于SARSA算法、固定信噪比门限的2种矿井自适应OFDM调制系统性能进行仿真对比,结果表明:矿井小车在匀速和移动速度变化状态下,基于Q-学习算法的自适应OFDM调制系统平均误码率分别为1.1×10~(-3),2.1×10~(-3),总吞吐量分别为3 115bit,2 719bit,均优于基于SARSA算法和固定信噪比门限的自适应OFDM调制系统,且系统中Q-学习算法收敛速度优于SARSA算法。     

AOS中基于最优帧长的链路自适应联合优化方法

针对AOS中数据传输误码率高的问题,导致系统吞吐量低的问题,提出基于最优帧长的链路自适应联合优化方法。该方法以系统吞吐量最大化为目标,联合可变帧长,自适应编码调制和混合自动重传请求技术进行优化,根据信道状态信息分配下一帧传输最佳的帧长和编码调制方式,并对出错数据进行纠错和重传,最终提升系统吞吐量。仿真验证表明,与AMC-HARQ和AMC-ARQ方法相比,该方法在保证系统误帧率的同时,提高了系统的吞吐量。     

基于STN LCD驱动控制芯片的显示控制电路设计

设计了一种灰度STNLCD驱动控制芯片的显示控制部分。面板参数的漂移和不同厂商之间的参数的差异,在STNLCD显示系统的器件选择时容易导致灰度显示的失真,这就要求驱动控制芯片在灰度输出时有较大的灵活性。在设计中采用FRC／PWM相结合的灰度调制方式,通过设置灰度寄存器的值来调整灰度的深浅,使之符合所选择的LCM的最佳特性。同时在控制电路中上加入屏幕的部分显示驱动、滚屏以及图像的硬件翻转等功能,最后在设计中考虑了功耗的优化和显示效果的提高。     

基于并行多方向注意力的无监督视频目标分割

时空特征传播对准确的无监督视频目标分割任务至关重要.但是,由于现实中视频的复杂性,导致时空特征学习与传播变得十分具有挑战性.在本文中,提出了两个新颖的模块分别用于增强视频中目标的空间和时间表示.具体来说,首先,针对当前帧,在空间上提出一个新颖的多方向注意力模块,旨在沿着水平、垂直与通道方向上分别提取注意力图.同时,设计了一个并行时序模块用于整合当前帧和之前帧的信息.该模块并行地计算出连续帧之间的二阶相似度,并且根据该相似度图重新对当前帧特征进行加权与增强.此外,该相似度图还直接生成一个有效的掩膜,用于进一步增广当前帧中目标的特征表示.接着,将上述空间和时间特征进行融合以获得最终增广的时空特征表示,并将其输入解码器来预测当前帧中待分割目标的掩膜.在三个主流无监督视频目标分割数据集上的大量实验结果表明,本文提出的方法与当前最新方法相比取得了领先的性能.相关代码将公布在https://github.com/su1517007879/MP-VOS.     

基于微粒群算法的OTSU图像分割方法

本文研究了图像闽值分割方法中常用的OTSU算法,在此基础上提出了基于微粒群算法的OTSU图像分割方法,该方法利用微粒群算法的快速全局寻优,确定图像的分割闯值所对应的灰度值,在该灰度值下目标和背景的方差最大。实验中选用了像素分别是8位和16位的两幅图片来进行分割,得到了较好的分割效果,而且该方法大大提高了计算速度,是一种有效的图像分割方法。     

用于压缩感知的DMD控制系统设计

基于数字光处理(DLP)的数字微镜器件(DMD)灰度控制主要针对视频应用,故帧频较低,只有约60～120 Hz,而用DMD实现的伯努利矩阵作为压缩感知测量矩阵,是0-1二值矩阵,不需要灰度控制,且帧频要求通常在数千帧每秒.研制了基于Xilinx公司Virtex-5 FPGA的DMD控制系统来实现伯努利矩阵,系统由随机数发生器(RNG)、DDR2 SDRAM控制器、DMD控制器等模块组成.随机数发生器产生的随机数存储在DDR2 SDRAM中,实现与DMD的高速数据传输.经验证,该系统可实现二值高速显示,帧频可达到2 kHz.     

基于FPGA的调制波周期归一化PWM研究

研究调制波周期归一化脉冲宽度调制(PWM),把数字系统中用于记录存储数据Ram的地址Address与PWM脉冲宽度相互映射,给出一般性结论。基于这一模型结构,设计调制波周期归一化PWM的现场可编程门阵列数字系统。针对设计该数字系统时出现的包括模拟量数字化、调制比M、载波比N以及调制波周期归一化PWM各环节具体数字化实现等问题予以分析并解决。对周期脉冲值Pn进行简单设置,便可快速实现调制波周期归一化PWM模型结构的波形输出。     

Transmission of gray level images by multilevel dither techniques

Dither techniques were invented to display pictures using bilevel media, but yet give the visual appearance of many shades of gray. With the advent of several new display media which can show more than two gray levels at each sample (e.g. 4 or 8 levels), extension of the dither to multilevels is required. We present such an extension in this paper. We also show how dithered images with few levels (e.g. 4 or 8) can be converted into many gray levels for display on cathode ray tubes. Techniques for hierarchical transmission are developed in which the first stage results in a two-level dithered image at about 40% of and 20% of the total bits for four and eight levels ditheres images, respectively. A good quality image is obtained at one bit per pel if eight level dither is used with gray level reconstruction. This compares favorably with the state of the art predictive and transform coding systems.     

A 12‐bit segmented resistor‐capacitor digital‐to‐analog converter for a display driver IC of a large TFT‐LCD panel system

Abstract— A 12‐bit segmented R‐C DAC to support a linear gamma curve has been proposed and fabricated in a 720‐channel LCD source driver with a 16‐V 1‐poly 3‐metal high‐voltage CMOS process. The proposed DAC has a global resistor string and sample‐and‐hold buffers. A MSB voltage selected by the upper 6 bits of input data and a LSB voltage selected by the lower 6 bits of input data are summed by using a sample‐and‐hold operation with offset cancellation in the proposed DAC. The measured DNL was less than 0.3 LSB, and the output voltage deviation was less than 3 mV in all gray levels. Although two sample‐and‐hold buffers were adopted to operate alternatively, the die size was as small as 24.9 mm², which was only an 8.3% increase compared to that of a conventional 8‐bit 720‐channel source driver. Because of its good performance with small area, the proposed DAC can be a good low‐cost solution for a 10‐bit TV system.     

Active matrix field sequential color electrically suppressed helix ferroelectric liquid crystal for high resolution displays

In this article, we disclose a 3‐inch 250ppi active matrix field sequential color (FSC) display based on electrically suppressed ferroelectric liquid crystal (ESHFLC). ESHFLC's ultra‐fast response time (~10 μs at 6.67 V/μm) enables the display resolution to be tripled via FSC technique. The photo‐alignment technology provides ESHFLC with optimal anchoring energy that contributes to a high contrast ratio over 10 K:1 on single pixel level measurement. A specific 3T1C pixel circuit is designed to generate continuous gray scale from FLC binary switching by utilizing the pulse width modulation concept. The low temperature poly silicon thin‐film transistor array has been used to fabricate the FSC ESHFLC display panel. We achieved an 8‐bit gray level for each color subframe, that is, R, G, and B colors that results in 24‐bit color images. We believe, because of the good optical quality and cost‐effective fabrication, this display may replace in‐plane switching or fringe‐field switching in the near future for the portable device market. Moreover, high resolution FSC ESHFLCs can find applications in the emerging virtual reality displays.     

LED显示屏高灰度扫描控制的FPGA实现

本文在分析LED显示屏的显示扫描控制方法的基础上,提出了用并行结构实现高灰度扫描控制的方案,设计了基于FPGA的8位并行输入LED扫描控制芯片,并结合外围电路、显示面板及计算机构成了LED大屏幕显示系统,实现了LED显示屏的256级灰度显示,在简化系统硬件结构的前提下取得了清晰稳定的画面显示。     

A novel OLED controller with fractal scan scheme

Based on the mathematical model of the optimal scan architecture of gray-scale imaging, this paper presents the design and logic implementation of a novel organic light-emitting display (OLED) gray-scale controller with the fractal scan scheme to efficiently increase the scan utilization and imaging quality. Through the exploration of the sub-space code sequences and bit code sequences for different gray levels, the authors first complete the design and implementation of the parameterized fractal scanning IP core for various gray levels, which can be used in every flat panel display controller. And then a novel OLED gray-scale controller embedded in a fractal scanning IP core is designed. It can efficiently increase the imaging gray levels and speed up frame frequency of display systems. Serial applications and tests indicate that the novel controller can obtain 100% scan utilization and a significant decrease in the system clock frequency (a multiple of 29 for 256 gray levels), compared with the traditional scan methods. With the proposed method there is no need of using high-speed IC circuits to realize the high articulation and resolution display of video images. Thus, the paper provides a new approach and an engineering way to solve one of the pressing problems of high-resolution flat panel display technology.     

直方图重建图像细节增强算法

针对传统大动态范围图像数据压缩方法易受场景变化影响,量化后的8位显示图像整体模糊、图像细节和弱小目标丢失问题,提出了一种基于直方图重建图像细节增强算法。对图像直方图统计值进行重新赋值,保留图像中出现的细节部分,并缩小相邻灰度级间间隔;采用二维Gabor滤波器来模拟视觉感知系统,将Gabor滤波器与图像进行卷积运算,得到滤波后的平滑图像;采用局部对比度增强方法来增强图像细节部分,并将增强后的中间结果线性映射为8位显示图像。实验结果表明,与其他大动态范围数据压缩方法相比,该算法量化后图像清晰度高,无图像细节和目标丢失现象。     

Development of an 8‐bit VGA LCOS microdisplay with FSC modes using a low‐cost process

Abstract— A VGA‐resolution LCOS microdisplay operated in the field‐sequential color (FSC) mode was fabricated using a low‐cost process. An 8‐bit digital data driver with digital‐to‐analog converters, which can realize a 256‐level gray scale and gamma compensation, has been integrated into a color microdisplay. A top‐to‐bottom approach to the design of an FSC LCOS microdisplay is described. The design of the silicon‐backplane circuits is outlined in detail. Finally, a prototype of this display and its imaging performance are discussed.     

A large high‐resolution electroluminescent display

A new high‐resolution electroluminescent display with a luminance of 100 cd/m² (30 fL) and 6‐bit gray scale to support real‐time video up to a bandwidth of 45 MHz has been developed under the Defense Advanced Research Projects Agency's Technology Reinvestment Project. Production units are now installed in the M1A2 Abrams Main Battle Tank upgrade program and are used to display the tank commander's new infrared “second‐generation FLIR” imagery.     

基于调和映射的三维医学图像增强系统

医学成像仪器产生12位的体数据,然而普通显示器只支持8位的灰度图。如果使用普通显示器来显示医学图像,显卡会自动将这些12位数据转化成8位数据,这就造成了数据动态范围被压缩。解决这一问题,在2D领域通常使用昂贵的医学专用灰阶显示器。在3D领域却限制了医生使用三维可视化软件。尝试将一些在2D图像处理中使用的图像增强技术如加权平均模板,不同程度曝光等来实现色调映射算法等应用到三维体数据的显示当中,通过种种复杂的数据变换,使得在普通显示器上显示的8位灰度图呈现出更高的动态范围,得到更为生动、更加丰富的显示效果。这种技术也可以实现任意位数的转化,使得12位显示器的显示效果也可以得到增强。