搜索结果: 1-15 共查到“光学工程 shift”相关记录29条 . 查询时间(0.093 秒)
Chiral Metamaterial Produces Record Optical Shift Under Incremental Power Modulation
Chiral Metamaterial Produces Record Optical Shift Under Incremental Power Modulation
2017/3/14
Georgia Institute of Technology researchers have demonstrated an optical metamaterial whose chiroptical properties in the nonlinear regime produce a significant spectral shift with power levels in the...
Reflection-type holographic disk-type memory using three-dimensional speckle-shift multiplexing
holographic memory reflection-type hologram speckle shift multiplexing
2016/11/22
This review presents a reflection-type holographic memory using three-dimensional(3D) speckle-shift multiplexing. First, the schematic of the proposed memory system was described. Then, experimental d...
基于颜色与梯度方向联合直方图的Mean Shift跟踪
目标跟踪 Mean Shift跟踪 联合直方图 光照变化 目标旋转
2015/12/26
由于单一的基于方向纹理特征的模板匹配跟踪算法不能准确跟踪目标旋转,无法应对光变、目标旋转以及部分遮挡的复杂场景下的跟踪,本文在mean shift算法框架下提出一种基于颜色与梯度方向联合直方图的跟踪算法,该算法通过扩展直方图的维度将颜色与梯度方向特征融合到一个直方图中构成联合直方图。由光照变化模型计算得出光变因子表征光照变化程度,并作为两种特征的比例系数对联合直方图归一化。当光变因子小于某个阈值则...
Non-reciprocal phase shift induced by an effective magnetic flux for light
Non-reciprocal phase shift induced effective magnetic
2015/8/6
Photons are neutral particles that do not interact directly with a magnetic field. However, recent theoretical work1,2 has shown that an effective magnetic field for photons can exist if t...
基于在线支持向量机的Mean Shift彩色图像跟踪
Mean Shift HSV颜色空间 在线支持向量机
2014/3/18
为了解决传统Mean Shift跟踪方法中目标模板只能从单一图像建立，且很难更新问题，提出了一种新的Mean Shift彩色图像跟踪方法。将RGB颜色空间投影到HSV颜色空间，建立了基于HSV颜色空间的统一直方图核函数模型。为了实现模板在线更新，引入在线支持向量机，推理了基于HSV空间的在线支持向量机的Mean Shift跟踪算法，从而适应目标因尺寸、姿态及光照造成的模型变化。为了验证算法的有效性...
基于改进Mean-Shift算法的红外小目标跟踪
Mean-Shift 红外小目标 自适应 非线性 融合
2016/8/23
复杂背景下的红外小目标跟踪在目标跟踪领域一直是重要的研究方向。由于小目标体量小、 机动性大，而红外图像大多受到严重的背景噪声和热噪声影响，使得针对红外小目标的跟踪大多出错率高，鲁棒性不强。针对红外小目标的跟踪，提出了一种改进的Mean-Shift 算法。结合图像的统计特性，提出了一种自适应非线性算法对图像进行处理；同时融合了图像的梯度直方图对目标进行描述。实验通过对高强度噪声和高遮挡环境下视频目标...
模板自适应的Mean Shift红外目标跟踪
MeanShift 图像矩 机器学习 增量式支持向量机
2016/8/19
为了解决Mean Shift跟踪算法中目标模板只能从单一图像建立且很难更新问题，提出了一种结合改进的Mean Shift与增量式支持向量机的红外目标跟踪算法。首先，根据目标区域的灰度直方图对目标进行描述，然后采用标准Mean Shift搜索目标，结合子图图像矩特征进行二次搜索，再计算下一帧搜索的窗口大小，以解决目标尺寸明显变化时造成目标丢失的问题。同时，针对目标遮挡易导致跟踪失败的问题，引入机器学...
基于改进Mean Shift算法的实时视频目标跟踪
嵌入式 视频目标跟踪 图像传感器 Mean Shift算法 实时
2012/12/13
设计了一套嵌入式平台上实现的视频目标跟踪系统.该系统采用CMOS图像传感器获取视频信号,利用Z228多媒体芯片自带的ARM9处理器完成视频信号的控制,并通过MPEG-4硬件编码器实现视频信号的压缩.用Mean Shift算法跟踪运动目标,针对其收敛的局限性设置多个搜索点来提高其跟踪效果.通过减少采样点和标记已计算点来提高代码运行速度,增强了跟踪的实时性.实验结果表明,本系统能以27 fps速率连续...
自适应窗口选取的Mean-Shift目标跟踪
Mean-Shift 目标跟踪 核函数带宽 自适应性
2012/12/12
当目标尺度发生变化时,传统Mean-Shift跟踪算法因跟踪窗口尺寸不变容易导致跟踪目标丢失,为解决此问题,本文提出一种带宽自适应算法对目标尺度变化进行检测,从而实现模板更新.该算法分别将模板图像与当前帧目标图像分割成等间隔半径的若干同心圆,通过计算模板图像与当前帧图像不同环层之间相似性度量,根据相应环层之间相似性度量关系确定当前帧模板带宽更新参量,最后利用kalman滤波完成模板尺度更新,从而实...
Information Encryption Based on Using Arbitrary Two-Step Phase-Shift Interferometry
Deterministic Phase-Encoded Encryption Arbitrary Two-Step Phase-Shift Interferometry Lenticular Lens Array
2013/1/30
A deterministic phase-encoded encryption system is proposed. A lenticular lens array (LLA) sheet with a particular LPI (lenticular per inch) number is chosen as a modulator (key) instead of the random...
This work investigates the effect of phase fluctuation averaging on phase fluctuation induced by intrachannel four-wave mixing (IFWM) in highly dispersed differential phase-shift keying transmission s...
Compact refractometer based on extrinsic-phase-shift fiber Bragg grating
Refractometer Extrinsic-phase-shift Fiber Bragg grating Compact sensing structure Large measurement range
2013/5/27
A novel method to measure refractive index of liquids by using an extrinsic-phase-shift fiber Bragg grating(EPS-FBG) is proposed and experimentally demonstrated. The EPS-FBG is obtained by separating ...
160 Gb/s All-Optical Binary-to-Quaternary Amplitude Shift Keying Format Conversion
Nonlinear optics fibers Ultrafast nonlinear optics
2015/5/21
160Gb/s all-optical binary-to-quaternary amplitude shift keying format conversion is carried out in nonlinear optical fiber. This scheme, which also acts as a 2-bit digital-to-analog convertor, has be...
Bit-error Rate Performance of Nyquist Wavelength-Division Multiplexed Quadrature Phase-Shift Keying Optical Signals
Coherent communications Multiplexing Optical communications
2015/5/20
We measure bit-error rates of polarization-multiplexed Nyquist-WDM QPSK signals,which have rectangular spectral shapes and channel spacing equal to the symbol rate. The spectral efficiency of 4 bit/s/...
A Modulation Scheme for 100Gb/s Minimum-Shift Keying Format based on Imbalanced Bias in IQ Components
Minimum-Shift Keying IQ Components Imbalanced Bias
2015/5/15
We propose an optical MSK modulation scheme to achieve the 100Gb/s MSK signal with constant envelope and continuous temporal phase shift. The investigation on the transmission performance clearly demo...