基于视频对象的区域分割及其应用

为适应MPEG-4基于对象的应用,提出一种基于视频对象的区域分割算法。在视频对象的指导下,利用均值漂移进行分割,性能比传统均值漂移算法在计算时间、占用内存等方面均有提高,适用于运算速度要求高和处理器资源有限的情况。将分割结果应用于区域指导的图像插值,能保证较快的处理速度和兴趣区域较好的图像质量。实验结果证明了该方法的有效性。     

基于联合特征直方图的均值漂移目标跟踪算法

针对单一颜色特征跟踪性能差的缺点, 提出一种基于联合特征直方图的均值漂移目标跟踪算法. 采用颜色、边缘、运动3 个具有一定互补性的信息进行联合概率跟踪, 以提高目标模型的描述能力; 利用运动信息修正颜色和边缘模型核函数, 用以克服背景颜色、轮廓对跟踪效果的影响; 根据各特征所占权重, 运用自适应融合法生成关联特征直方图, 并将所构建的目标模型融合到mean shift 跟踪框架中, 实现目标跟踪. 实验结果表明, 所提出的算法具有较高的准确性.

     

Robust integrated shift register circuit over clock noises for in‐cell touch applications

This paper proposes an integrated shift register circuit for an in‐cell touch panel that is robust over clock noises. It is composed of 10 thin film transistors and 1 capacitor, and the time division driving method is adopted to prevent the negative effect of display signals on the touch sensing. Two pre‐charging nodes are employed for reducing the uniformity degradation of gate pulses over time. In particular, the proposed circuit connects a drain of the first pre‐charging node's pull‐up thin film transistor (TFT) to the positive supply voltage instead of clock signals. This facilitates to lower coupling noises as well as to clock power consumption. The simulation program with an integrated circuit emphasis is conducted for the proposed circuit with low temperature poly‐silicon TFTs. The positive threshold voltage that shifts up to 12 V at the first pre‐charging pull‐up TFT can be compensated for without the uniformity degradation of gate pulses. For a 60‐Hz full‐HD display with a 120‐Hz reporting rate of touches, the clock power consumption of the proposed gate driver circuit is estimated as 7.13 mW with 160 stages of shift registers. In addition, the noise level at the first pre‐charging node is lowered to ?28.95 dB compared with 2.37 dB of the previous circuit.     

基于mean-shift全局立体匹配方法

针对图像全局立体匹配精度高、计算量大的问题,提出基于mean shift图像分割的全局立体匹配方法。首先,通过mean shift算法对图像进行分割,获取图像同质区域数量和区域的标号。在计算匹配代价时,根据像素所属的分割区域,对像素进行筛选,从而提高匹配代价计算速度;其次,在代价聚合前,将mean shift算法获取的同质区域数K值赋值给K-means聚类算法,对像素再次聚类,提高立体匹配精度和速度;最后通过TRW-S置信传播解决能量最小化问题。实验表明,该算法明显提高了匹配的准确性和速度,与单纯的全局匹配算法相比,具有更大的优势。     

基于语义与规则的有标复句层次体系研究

汉语复句层次关系分析是中文信息处理领域极具挑战性的课题之一。为解决关系词标识信息不充足所导致的复句层次关系识别准确率下降问题,挖掘了影响分句关联的形式化语义知识,在此基础上构建了小句关联体识别算法并将其应用于相应的复句层次判定规则之中,以辅助分析其层次关系;对于其余单、多重有标复句的层次识别,使用基于搭配规则的移进-归约算法;最后提出了一种语义与规则相结合的复句层次分析模型。实验结果表明,此方法在一定程度上提高了复句层次关系识别的准确率。     

两轮摩托车变挡机构动力学分析

用Adams建立某两轮摩托车的虚拟样机,对其变挡机构进行动力学仿真计算,找出影响变挡脚踏力的关键因素,提出优化设计思路,解决该车在使用过程中脚踏变挡不顺畅且费力的问题,提高该车型的综合性能.     

一种基于均值偏移的自动运动分割方法

运动分割是计算机视觉领域研究的重要内容。提出一种基于均值偏移的自动运动分割算法。该方法首先用特征点匹配关系获得特征点的运动轨迹,并以轨迹的运动向量作为特征,再用均值偏移算法对轨迹的运动向量进行聚类。均值偏移缩小相似的运动向量之间的差别,同时扩大不同运动的运动向量之间的差距。为了自动获得运动分类数,还提出了一种基于非参数核密度的自动分类方法,该方法通过估计运动向量的密度分布,用核密度图自动确定运动分类数。实验结果表明,该算法分割精度高、鲁棒性好,能够自动确定运动分类数。     

Modeling the impact of spectral sensor configurations on the FLD retrieval accuracy of sun-induced chlorophyll fluorescence

Chlorophyll fluorescence is related to photosynthesis and can serve as a remote sensing proxy for estimating photosynthetic energy conversion and carbon uptake. Recent advances in sensor technology allow remote measurements of the sun-induced chlorophyll fluorescence signal (Fs) at leaf and canopy scale. The commonly used Fraunhofer Line Depth (FLD) principle exploits spectrally narrow atmospheric oxygen absorption bands and relates Fs to the difference of the absorption feature depth of a fluorescensing and a non-fluorescensing surface. However, due to the nature of these narrow bands, Fs retrieval results depend not only on vegetation species type or environmental conditions, but also on instrument technology and processing algorithms. Thus, an evaluation of all influencing factors and their separate quantification is required to further improve Fs retrieval and to allow a reproducible interpretation of Fs signals.Here we present a modeling study that isolates and quantifies the impacts of sensor characteristics, such as spectral sampling interval (SSI), spectral resolution (SR), signal to noise ratio (SNR), and spectral shift (SS) on the accuracy of Fs measurements in the oxygen A band centered at 760 nm (O₂-A). Modeled high resolution radiance spectra associated with known Fs were spectrally resampled, taking into consideration the various sensor properties. Fs was retrieved using the three most common FLD retrieval methods, namely the original FLD method (sFLD), the modified FLD (3FLD) and the improved FLD (iFLD). The analysis investigates parameter ranges, which are representative for field and airborne instruments currently used in Fs research (e.g., ASD FieldSpec, OceanOptics HR, AirFLEX, AISA, APEX, CASI, and MERIS).Our results show that the most important parameter affecting the retrieval accuracy is SNR, SR accounts for ≤ 40% of the error, the SSI for ≤ 12%, and SS for ≤ 7% of the error. A trade-off study revealed that high SR can partly compensate for low SNR. There is a strong interrelation between all parameters and the impact of specific parameters can compensate or amplify the influence of others. Hence, the combination of all parameters must be considered by the evaluation of sensors and their potential for Fs retrieval. In general, the standard FLD method strongly overestimates Fs, while 3FLD and iFLD provide a more accurate estimation of Fs. We conclude that technical sensor specifications and the retrieval methods cause a significant variability in retrieved Fs signals. Results are intended to be one relevant component of the total uncertainty budget of Fs retrieval and have to be considered in the interpretation of retrieved Fs signals.     

基于FPGA的铁路移频信号测试系统设计

介绍了一种基于FPGA和单片机的移频信号检测系统新方案,对移频信号进行实时检测和处理,并给出系统的硬件构成框图、硬件设计和软件设计.该移频信号检测系统具有集成度高、电路简单、接口方便、运算速度快、精确度高、实时性好等优点.     

基于梯度特征与彩色特征相融合的mean shift跟踪方法

针对mean shift跟踪方法中存在的光照变化不稳定问题,提出了基于梯度特征与彩色特征相融合的mean shift跟踪方法。首先分别提取目标的梯度特征和彩色特征,利用多尺度的相似度计算方法进行特征的匹配,然后通过最大化相似度对目标进行跟踪。通过物体和人体等运动目标的跟踪,验证了改进的跟踪算法在光照变化情况下的鲁棒性优于原有的算法,显著降低了跟踪位置误差。