军车驾驶员的速度预测和动作协调能力的实验研究

目的通过分析两项分测验中不同水平军车驾驶员的成绩,验证海军不同水平军车驾驶员的速度预期能力与动作协调能力的差异,以预防交通事故发生。方法选取90名军车驾驶员为被试,以他们在两项分测验中的反应时为指标,考察了不同水平驾驶员对不同运动速度的目标的预期反应能力和动作协调能力。结果 (1)当目标物体运动速度为每秒80、110、和140像素时,汽车驾驶员会提前预测,并且优秀驾驶员、一般驾驶员和较差驾驶员判断的误差达到显著性差异水平;(2)当目标物体运动速度为每秒170、和200像素时,汽车驾驶员会推迟预测,并且优秀驾驶员、一般驾驶员和较差驾驶员判断的误差达到显著性差异水平;(3)目标刺激在三组运动,三组静止条件下,优秀驾驶员、一般驾驶员和较差驾驶员的判断反应时差异显著。结论 (1)汽车驾驶员在对目标对象速度预测中,速度较慢的运动目标大多被试提前预测,速度较快的运动目标大多被试则推迟预测,差异非常显著;(2)追碰静止的目标的反应时比追碰运动目标的反应时要短,二者的差异非常显著。     

公共海报中双关图形的眼动特征研究

目的 通过对比有无双关图形,以及在双关条件下“图底共线”与“图底共形”两种不同图底关系类型对人观看海报时的眼动行为和观后评价的影响,帮助海报设计师理解观者的认知方式并应用到设计实践中。方法 选取四张应用双关图形的公共海报,将其“去双关”处理形成八个刺激材料。使用眼动仪收集被试的眼动数据,并以问卷调查作为辅助研究方法获取被试的观后评价。结果 实验发现双关图形的应用可以引起更长的注视点持续时间与更低的注视频率。在双关条件下,图底关系类型对跳视行为有影响。结论 双关图形的应用使海报信息的接收难度增加,可以引起人更加活跃的认知处理。在双关条件下,图底共形图形的信息表达更鲜明,而图底共线图形的布局功效更高。     

双回路图的部分逆M矩阵完备

逆M矩阵是一类非常重要的非负矩阵,在生物学、物理学等很多领域中都得到了广泛的应用．利用图论理论研究逆M矩阵的完备问题是逆M矩阵研究领域的一个重要方向．双回路图是由两条简单有向回路在任意多个顶点处相交所构建的有向图．本文对此类图形的逆M矩阵完备问题进行了研究,给出了此类图形所对应的部分矩阵在两种不同情况下具有逆M矩阵完备的充分必要条件：当双回路图中的顶点均已知时,每一条回路的回路积均小于其对角元素的乘积;当双回路图中可包含未知顶点时,每一条回路至少包含一个未知顶点．同时,本文给出了具体的完备算法,并通过数值算例验证了算法的有效性．     

颜色、闪烁冗余代码对图形的突显工效研究

实验以反应时和正确率为指标，对比研究了4种颜色和闪烁分别作为冗余突显代码在图形显示界面中的工效。实验结果表明：图形视觉材料显示中，颜色和闪烁的突显方式显促进了被试视觉搜索绩效；而将颜色和闪烁分别作为冗余突显代码时，均不能显提高被试的视觉搜索绩效。     

改进的粒子滤波目标跟踪算法

针对环境迁移、目标被遮挡或姿态变化较大时传统粒子滤波算法的鲁棒性不强的问题,提出一种改进的粒子滤波目标跟踪算法。建立目标模型时,将目标的HSV颜色特征和Uniform LBP纹理特征进行加权融合;粒子重采样过程中,采用加权随机采样方法,将粒子权值作为重采样的影响因子而非决定因子,以提升粒子多样性,降低粒子衰退对目标跟踪的影响;目标被干扰时,采用卡尔曼滤波对目标位置进行偏移校正,以获取目标正确位置;最后采用模板更新策略对目标模板进行实时更新。实验结果表明：相较于传统粒子滤波算法和CMT算法,本文算法对复杂环境中目标被遮挡和姿态变化的情况下都具有较好的鲁棒性。     

基于序贯蒙特卡罗的多线索目标跟踪算法

颜色直方图对噪声和部分遮挡不敏感,当背景颜色与目标颜色相近时,会影响跟踪效果.本文提出一种有效的基于多线索融合的序贯蒙特卡罗图像序列跟踪方法,采用颜色直方图和边缘直方图与序贯蒙特卡罗算法结合起采进行视频跟踪.颜色直方图和边缘直方图一起构建目标观测似然函数.在序贯蒙特卡罗方法的框架下,采用观测模型函数获取图像序列中目标位置的后验概率分布.实验结果表明,结合图像颜色与边缘特征,在序贯蒙特卡罗的框架下可以取得更为有效和稳健的跟踪效果.     

电子影像科学中若干名词介绍

1色调颜色色彩各异，它的最重要的表征叫做色调，其物理意义是各种颜色对应一定波长的光谱。它所发出的光或反射、透射的光，它们的光谱能量的主要成分不同，使人的颜色感觉也不同。对应于每一单色光都有一固定的波长。2饱和度平常我们经常谈到颜色的深、浅，说的就是颜色的饱和度，即是指一种颜色的鲜明程度。如果饱和度高．那么这种颜色就是较深，如深红、深绿，反之则成为浅色调。所以也可以说他和度是颜色浓淡表现的程度。其物理意义是，物体表面反射光（或自发光）中白色成分越少，它的色彩他和度越大，反之越小。当我们把颜色成分中掺…     

复杂背景及遮挡条件下的运动目标跟踪

CamShift算法应用于复杂背景及遮挡条件下视频跟踪时,极易出现跟踪失效和目标丢失。本文提出基于颜色、纹理及目标运动信息的综合特征用于改进CamShift算法,结合Kalman滤波器对目标运动状态进行预测提高了复杂背景下运动目标的跟踪稳定性和跟踪精度。在目标发生遮挡时,通过目标遮挡前的先验信息进行最小二乘拟合及目标运动轨迹外推,预测目标运动位置信息,有利于遮挡结束时对运动目标的重新捕获。多组实验结果及性能分析表明,该算法在复杂背景及目标被短时遮挡情况下,可以实现目标的持续、稳定跟踪,并具有较好的实时性。     

离散度参数对规则多边图形认知工效的影响

本研究用实验方法研究离散度参数对规则多边图形认知工效的影响。实验的自变量是图形的离散度参数，因变量是各离散度图形信号的反应时。实验的刺激材料是２５个离散度为０．３～０．７的规则多边图形。刺激材料的呈现与被试的反应记录都由计算机控制。结果表明：离散度适中（０．５左右）及偏小的图形信号认知工效较高，离散度从０．５增大到０．６，认知工效迅速下降，离散度继续增大，认知工效仍有下降，但趋势平缓。     

有遮挡二维物体的识别研究

本文提出一种识别和定位平面上物体的方法。这种方法能处理由于物体间相互接触或重叠所引起的局部遮挡问题,并且对比例系数不要求有预先的估计。通过对物体边缘线的折线逼近,获得物体的描述。同时,引入线段权值的概念,用权值的大小来反映根据该线段把一个物体与其它物体区分开的能力的高低。识别时,计算图象线段与模型线段间的不相拟度,找出匹配的线段对,从而产生图象中某处可能有某物体的假设。根据假设下的坐标变换,将模型线段映射到周象坐标系内,寻找模型上其它与图象匹配的线段,对原假设进行验证,并对坐标变换进行修正。该方法已被用来识别部分遮挡的物体,实验结果表明这个方法已达到预期的效果。     

Human Recovery of Shape from Profiles

A single profile of a solid object contains much information about the shape of the object. Viewing the changing profiles of a moving object provides even greater information about the shape of the object. Few computational models of this process have been applied to the human ability to recover the shape and motion of solid objects from their changing profiles. We propose a theory that relates measurable quantities of changing two-dimensional (2-D) profiles to structural properties of three-dimensional (3-D) surfaces in motion. The relevance of this theory to human perception is shown by relating theoretical predictions to existing psychophysical results as well as additional demonstrations of human recovery of shape from profiles.

     

A technique of object‐adaptive vertex‐based shape coding for MPEG‐4 videos

The MPEG‐4 visual standard is the first international standard that allows the transmission of arbitrarily shaped video objects and provides technologies to view, access, and manipulate objects rather than pixels. It addresses the encoding of video objects by shape coding, motion estimation, and texture coding for interactivity, high compression, and scalability. Current binary shape‐coding techniques can be classified into two categories: bitmap based and contour based. O'Connell (1997) proposed an object‐adaptive vertex‐based shape‐coding method to improve the efficiency of shape coding. This method encodes the relative locations of a video object's vertices by adapting the representation to the dynamic range of the relative locations and by exploiting an octant‐based representation for each relative location. We propose an extension of O'Connell's method. Two relative locations of a video object's vertices are grouped and the x pairs and y pairs of the locations are encoded, respectively. Simulation results demonstrate that our method outperforms O'Connell's method. © 2001 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 277–282, 2000     

Consideration of existence of phase information of object shape in zeroth-order diffraction beam using electromagnetic simulation with aperture in front of objective

ABSTRACT

It has been reported that the shape of a measured object can be determined by detecting the change in phase distribution generated by a lateral shift of the object using speckle interferometry. In speckle interferometry technique, it was also reported that the shape of the object beyond the diffraction limit can be measured. In this study, the principle of this method is discussed through experiments and electromagnetic analysis. Accordingly, the results of the experiments and electromagnetic analysis of phase change only under zeroth-order diffraction light through the lateral shift of the object are investigated by shutting out the higher harmonic diffraction lights using an aperture in front of the lens. The results indicate that even if the image of the object cannot be focused upon, three-dimensional shape measurement can be performed by analysing only the zeroth-order diffraction light from the object.     

A Novel Contour Tracing Algorithm for Object Shape Reconstruction Using Parametric Curves

Parametric curves such as Bézier and B-splines, originally developed for the design of automobile bodies, are now also used in image processing and computer vision. For example, reconstructing an object shape in an image, including different translations, scales, and orientations, can be performed using these parametric curves. For this, Bézier and B-spline curves can be generated using a point set that belongs to the outer boundary of the object. The resulting object shape can be used in computer vision fields, such as searching and segmentation methods and training machine learning algorithms. The prerequisite for reconstructing the shape with parametric curves is to obtain sequentially the points in the point set. In this study, a novel algorithm has been developed that sequentially obtains the pixel locations constituting the outer boundary of the object. The proposed algorithm, unlike the methods in the literature, is implemented using a filter containing weights and an outer circle surrounding the object. In a binary format image, the starting point of the tracing is determined using the outer circle, and the next tracing movement and the pixel to be labeled as the boundary point is found by the filter weights. Then, control points that define the curve shape are selected by reducing the number of sequential points. Thus, the Bézier and B-spline curve equations describing the shape are obtained using these points. In addition, different translations, scales, and rotations of the object shape are easily provided by changing the positions of the control points. It has also been shown that the missing part of the object can be completed thanks to the parametric curves.     

Wireless measurement of Float-Sink motion of Variously-shaped objects in Gas-Solid fluidized bed

The float-sink motions of coarse objects in a gas–solid fluidized bed were investigated experimentally using a newly developed wireless sensor system. The Lagrangian sensor system developed by our previous study, which can measure the vertical position of a freely-moving object in an invisible system, was extended to measure the attitude angle and vertical position of variously-shaped objects simultaneously. The vertical motion of objects which have different shapes with the same mass and volume was measured using the Lagrangian sensor under the density conditions similar to the apparent density of the fluidized bed. The results demonstrate that the float-sink motions of objects in the gas–solid fluidized bed differ significantly depending on the shape of the object, even at the same density, in contrast to those in water. It was found that non-spherical objects tend to float more easily than spherical objects, which supports the numerical results shown in our previous study (Tsuji et al., Chem. Eng. Sci., 2022). Simultaneous measurement of the position and attitude angle highlights the importance of the angular motion of objects in terms of the float-sink motion. The interaction of the object with the media particles in the fluidized bed differs depending on the object shape, which indicates that each shape involves a unique float-sink mechanism.     

一种改进的Graph Cuts交互图像分割方法

本文提出了一种改进的Graph Cuts交互图像分割方法。Graph Cuts交互图像分割方法首先由用户选定部分像素作为对象和背景，其余像素为未知区域；然后根据以像素为顶点，以像素相邻关系为边，构造一个图；最后通过图的最小分割方法将图像分为对象和背景两部分。此方法分割图像的结果直接受到用户选定对象和背景像素操作的影响，对象和背景边界的像素容易被分割错误。我们分别对对象区域和背景区域进行腐蚀操作，使分割错误的像素重新变为未知区域（对于在对象或背景内部被错误划分的像素，可以利用类似画笔的工具，直接将其标为对像或背景），然后重新进行一次Graph Cuts分割。由于这次选定了大部分的对象和背景区域，实验结果表明，最后分割结果正确率明显提高了。     

A blind proposed 3D mesh watermarking technique for copyright protection

ABSTRACT

Watermarking provides an efficient mechanism for copyright protection of digital media by embedding information in the object to identify the owner. This paper proposed a watermarking technique that can successfully embed a grey-scale image in a 3D mesh object. In our proposed technique, each three vertices of the 3D object can hide one pixel from the secret image. The experimental results showed that the proposed technique has better visual quality on both the watermarked object and the extracted secret image.     

A multimodal approach for individual tracking of people and their belongings

Abstract

In this study, a fully automatic surveillance system for indoor environments which is capable of tracking multiple objects using both visible and thermal band images is proposed. These two modalities are fused to track people and the objects they carry separately using their heat signatures and the owners of the belongings are determined. Fusion of complementary information from different modalities (for example, thermal images are not affected by shadows and there is no thermal reflection or halo effect in visible images) is shown to result in better object detection performance. We use adaptive background modeling and local intensity operation for object detection and the mean-shift tracking algorithm for fully automatic tracking. Trackers are refreshed to resolve potential problems which may occur due to the changes in object’s size, shape and to handle occlusion-split and to detect newly emerging objects as well as objects that leave the scene. The proposed scheme is applied to the abandoned object detection problem and the results are compared with the state of art methods. The results show that the proposed method facilitate individual tracking of objects for various applications, and provide lower false alarm rates compared to the state of art methods when applied to the abandoned object detection problem.     

Comparison of uniform field and pattern electroretinograms of humans

The electroretinogram (ERG) is the voltage change recorded at the cornea in response to visual stimulation that reflects the summed electrical activity of different groups of retinal cells. The purpose of the current study was to determine whether the ERG elicited to luminance modulations of a uniform field could be used to simulate the shape of the pattern ERG (PERG) responses recorded to contrast modulation of pattern stimuli. We not only found that summing responses to luminance increments and decrements in the uniform-field ERG of humans could closely simulate the shape of the PERG responses but also that intra- and inter-subject variability of the various response parameters from simulations and actual PERG responses are not significantly different. These findings raise the possibility that the uniform field ERG can serve as a useful alternative to the PERG which is currently the electrodiagnostic test of choice for the clinical assessment of inner-retinal function.