约束纹理合成

对基于块的实时纹理合成算法进行扩展并应用到约束纹理合成中, 对瑕疵进行修复, 在纹理合成的过程中采用不同类型的纹理段寻找匹配, 并且利用可变大小的纹理块修复瑕疵的边缘处, 使修复后的图像在原来瑕疵的边界处没有明显边界感.     

稀疏纹理分类的研究

文章研究了视点和光照条件均未知的纹理图像分类,在滤波器输出的联合概率分布基础上,运用贝叶斯分类器和改进分类器进行分类,讨论了纹理的特征提取和用于纹理分类的方法.实验证明,本文算法可以较准确地进行纹理特征提取和分类,使得纹理分类工作变得有较强的实用性.     

Multi-layer synthesis of highly-structured texture

In this paper, a novel concept of multilayer synthesis and a general framework for texture synthesis method are presented. Within this framework, we first decompose the texture into the supposed pattern layer and material layer in the frequency domain by an E-texton extracting algorithm, then manipulate and extend them respectively according to their own personalities, and finally merge the newly synthesized pattern layer and material layer again to generate the final output. Experiment results show that our method not only greatly improves the synthesis quality for those cases that single-layer synthesis cannot handle well but also provides an ability of achieving various special synthesis effects.     

纹理图像的多分形特征

为尽可能保持图像信息的完整,以更好地刻画纹理图像的整体特征,在分析了多分形的基本理论、表示的物理意义和计算方法后,提出了基于多个无标度区的多分形分析方法。这种方法充分利用了图像各个尺度所包含的信息,弥补了传统多分形分析方法因为只选择某一个无标度区计算,而丢失诸多图像信息的不足。运用基于多个无标度区的多分形分析方法对纹理图像进行分析,分析结果对刻画纹理图像的整体特征及对分析复杂结构纹理图像具有指导意义。     

皮肤纹理检测技术

提出一种将基于粒子群模糊聚类算法的边缘检测方法和Gabor小波变换相结合来进行皮肤纹理检测的方法.用边缘检测的方法将明显具有很多边缘的肤色区域剔除,对于没有明显纹理的皮肤区域用Gabor小波变换进行皮肤的纹理检测.仿真结果表明,所研究的方法正检率获得提高,误检率有所下降,是一种有效的皮肤纹理检测技术.     

实时纹理映射单元

本文提出一个基于移动设备的图形加速卡纹理映射单元的硬件实现方案,本方案采用的是分级细化(MIPmapping)的纹理数据组织方式,映射函数为透视变换,纹理的后置滤波用最基本的三线性滤波方法,纹理存储器分成四个存储器组,只激活需要访问的存储器,以达到减小电能损耗的目的.并行双流水线结构的纹理映射单元,纹理存储带宽可以达到6.4Gb/s.     

实时纹理映射单元

本文提出一个基于移动设备的图形加速卡纹理映射单元的硬件实现方案,本方案采用的是分级细化(MIPmapping)的纹理数据组织方式,映射函数为透视变换,纹理的后置滤波用最基本的三线性滤波方法,纹理存储器分成四个存储器组,只激活需要访问的存储器,以达到减小电能损耗的目的。并行双流水线结构的纹理映射单元,纹理存储带宽可以达到6.4Gb/s。     

实时纹理映射单元

本文提出一个基于移动设备的图形加速卡纹理映射单元的硬件实现方案,本方案采用的是分级细化(MIPmapping)的纹理数据组织方式,映射函数为透视变换,纹理的后置滤波用最基本的三线性滤波方法,纹理存储器分成四个存储器组,只激活需要访问的存储器,以达到减小电能损耗的目的.并行双流水线结构的纹理映射单元,纹理存储带宽可以达到6.4Gb/s.     

Decoration of disclinations by solidification-induced band texture and focal-conic texture for a low-molar-mass liquid crystal

Two decoration techniques, solidification-induced band texture decora tion and focal-conictexture decoration, have been established to exhibit the director field of disclinations in a low-molar-mass methacrylate liquid crystal. The disclinations with strength s = 1/2 and s = ±1 are observed by the two decor ation methods. For the solidification-induced band texture decoration, the molecular orientation is perpendicular to the direction of the band. While for focal- conictexture decoration, it has been proved by the results of IR dichroism that the direction of the director is parallel to the direction of the focal-conic. Therefore, the sketch map of the molecular director filed can be mapped according to the morphological pattern of the solidification-induced band textureor focal-conic texture.     

掺杂钨带退火过程中的组织与织构演变

对掺杂钨带在1 000～1 500℃等温退火过程中的组织与织构变化进行研究.研究结果表明:未退火钨带为拉长的纤维组织,纤维宽窄不一,纤维内部存在长短不一的条形胞.于1 200℃,1h条件下退火时由于亚晶长大发生纤维宽化与纤维界的锯齿化,但无再结晶晶粒形成.当退火温度升高至1 400℃时,纤维界处出现细小的等轴状再结晶晶粒,这些再结晶晶粒的形成机制是亚晶转动.1 500℃退火后,再结晶晶粒增多,但长大不明显,这主要是由于K泡对亚晶界或位错的钉扎作用,使亚晶转动与亚晶界迁移受到阻碍,延缓了再结晶形核与核心长大.拉拔钨丝织构为[110]丝织构,钨丝轧制为钨带后,[110]丝织构转变为{001}＜110＞和{111｝＜110＞织构,1 500℃退火后,亚晶转动使钨带织构转变为沿α取向线均匀分布的{uvw}＜110＞织构,与拉拔钨丝的[110]丝织构类似.     

基于小波域的纹理图像分析

图像纹理信息丰富，准确地进行纹理特征描述，必须尽可能抓住其本质特征和属性。本文以小波域为分析基础，并结合图像特点，提出在全树状小波分解的基础上建立数学模型，在子图选择上用图像熵作为判据，使分解更有针对性并使计算效率得以提高。     

三维纹理映射技术研究

讨论了三维纹理映射技术中的过程纹理,分析了几种常用的过程纹理函数,运用线性插值和二次插值方法对传统的木纹函数进行了改进,保证木纹颜色变化的连续性,并给出了基于OpenGL实现颜色线性插值和二次插值的木纹效果实例.     

基于纹理结构相似性和边缘信息的水平集纹理图像分割

通过提取纹理特征对纹理图像进行分割是一类重要的纹理分割方法.传统的纹理特征提取通常根据像素邻域的灰度统计来获取,因为纹理具有方向性和尺度差异性,所以用传统方法提取纹理特征分割纹理图像是不准确、不稳定的.文章提出使用结构相似度(structural similarity index,SSIM)分析加噪图像和原始图像的相似...     

基于纹理对图像进行分类方法的研究

文章主要研究在不知道视点和光照条件下,根据纹理对图像进行分类的方法;过程是利用滤波器响应得到的特征向量,建立相应的纹理基元表示;用最近区域匹配分类和贝叶斯分类2种方法进行分类,并对2种算法进行了比较;结果表明,分类结果非常接近,均比较准确。     

A new texture analysis approach

A new texture analysis approach by using Gibbs random field model is discussed. A parameter vector is defined in order to compute potentials of textures. It is found that texture features can be provided by its corresponding parameter vector, and the vector can be estimated in terms of maximum potential. Conclusions can be inferred that this new method based on the maximum potential is valid. Supported by the National Natural Science Foundation of China Zhang Zhan: born in 1971, Ph. D. graduate student     

Early vision and texture perception

Texture perception has frequently been studied using textures constructed by repeated placement of micropatterns or texture elements. Theories have been developed to explain the discriminability of such textures in terms of specific features within the micropatterns themselves. For example, Beck observed that a region filled with vertical Ts is readily distinguished from one filled with tilted Ts but not from one filled with vertical Ls. He attributed this to the different distribution of oriented line segments present in the former case but not in the latter. However, Bergen and Julesz found that a region of randomly oriented Xs segregated from one filled with randomly oriented Ls, in spite of the identical distribution of oriented line segments in the two cases. They suggested that this discrimination might be based on the density of such features as terminators, corners, and intersections within the patterns. We note here that simpler, lower-level mechanisms tuned for size may be sufficient to explain this discrimination. We tested this by varying the relative sizes of the Xs and the Ls; when they produce equal responses in size-tuned mechanisms they are hard to discriminate, and when they produce different size-tuned responses they are easy to discriminate.     

Computing texture boundaries from images

Recent computational and psychological theories of human texture vision assert that texture discrimination is based on first-order differences in geometric and luminance attributes of texture elements, called 'textons'. Significant differences in the density, orientation, size, or contrast of line segments or other small features in an image have been shown to cause immediate perception of texture boundaries. However, the psychological theories, which are based on the perception of synthetic images composed of lines and symbols, neglect two important issues. First, how can textons be computed from grey-level images of natural scenes? And second, how, exactly, can texture boundaries be found? Our analysis of these two issues has led to an algorithm that is fully implemented and which successfully detects boundaries in natural images. We propose that blobs computed by a centre-surround operator are useful as texture elements, and that a simple non-parametric statistic can be used to compare local distributions of blob attributes to locate texture boundaries. Although designed for natural images, our computation agrees with some psychophysical findings, in particular, those of Adelson and Bergen (described in the preceding article), which cast doubt on the hypothesis that line segment crossings or termination points are textons.     

基于纹理特征的岩屑图像识别

岩屑是石油和地质分析重要的实物资料．在岩屑描述的过程中不同岩性主体本身的纹理各不相同,纹理差别较大的地层,可以直接通过纹理变化来判断岩性,进而确定砂泥岩百分比的变化．本文以纹理特征为基础,通过对各种岩屑对比度值的提取以及阈值的设定实现在混合岩屑中分辨出砂岩,泥岩和页岩．实验结果表明：算法有效且实用．     

与纹理无关的散焦测距方法的研究

计算机视觉中，景物三维重建的关键之一是从景物图像中获得景物目标到摄像机的距离．在此介绍一种基于散焦图像来计算景物距离的新算法．该方法通过改变镜头的光圈系数得到同一景物的2幅散焦程度不同的图像，用图像信号时域能量值表示其功率谱密度；应用一种动态参照技术，得到模糊参数值C，从而得到景物距离的估计值．这种方法具有标定简单（只有一个值需要标定）、计算量小、精度较高并且得到的估计结果与景物的纹理无关的特点．实验结果表明了该方法的有效性.