基于离散多小波变换的纹理分类

纹理分析在遥感、医学图像处理、计算机视觉及基于纹理的按内容检索的图像数据库等许多重要领域均有着广泛的应用.引入多小波理论,提出了基于多小波分解的纹理图像分类.通过一系列的实验并与单小波进行比较,实验结果表明,多小波分解比金字塔小波分解或小波包分解其分类准确率更优.     

一种新的自然纹理分类方法

纹理分类一直是图像处理领域重要的研究课题之一。目前,用数学方法描述纹理特征从而进行纹理分类非常流行,但这些方法无法消除纹理视觉特征和人们理解的纹理概念之间的语义障碍。提出了一种新的基于中文自然语言纹理描述词的纹理方法,把常见的自然纹理分为10大类别,然后利用小波包分解和最小二乘支持向量机对自然纹理进行分类,实现了纹理的视觉特征到语义描述的转换。实验结果证明,该方法在图像理解和基于自然语言的图像检索中有助于缩小纹理特征的数学描述和人类理解之间的“语义鸿沟”。     

基于无抽样小波变换和MCE训练的纹理分类

提出了一种新的纹理分类的方法,该方法把基于无抽样小波变换的特征提取器和基于欧几里得距离的分类器进行了合并。把方差、偏态系数、峰态系数、三者的联合及谱直方图作为描述纹理图像不相重叠的图像窗的特征。一个使用线性转换矩阵的特征提取器对分类导向的特征做进一步的提取。利用基于欧几里得距离的分类器,每个纹理图像不相重叠的图像窗被确定到属于它的那一类。基于最小分类错误训练方法的特征提取器和分类器设计的合并使分类错误达到了最小化。使用该方法对25类BrodTex纹理图像进行了评估,分类精确度达到90%以上。     

基于小波包变换和蚁群算法的纹理分类

提出了一种小波包变换和蚁群算法相结合的纹理分类新方法。首先采用小波包变换提取纹理图像的纹理特征向量,然后用蚁群算法进行训练和分类。实验表明小波包变换和蚁群算法应用到纹理分类领域,是一次有效的尝试。     

Analysis of wavelet packet and statistical textures for object-oriented classification of forest-agriculture ecotones using SPOT 5 imagery

Textural features of high-resolution remote sensing imagery are a powerful data source for improving classification accuracy because using only spectral information is not sufficient for the classification of objects with within-field spectral variability. This study presents the methods of using an object-oriented texture analysis algorithm for improving high-resolution remote sensing imagery classification, including wavelet packet transform texture analysis, the grey-level co-occurrence matrix (GLCM) and local spatial statistics. Wavelet packet transform texture analysis, with the method of optimization and selection of wavelet texture for feature extraction, is a good candidate for object-oriented classification. Feature optimization is used to reduce the data dimensions in combinations of textural sub-bands and spectral bands. The result of the classification accuracy assessment indicates the improvement of texture analysis for object-oriented classification in this study. Compared with the traditional method that uses only spectral bands, the combination of GLCM homogeneity and spectral bands increases the overall accuracy from 0.7431 to 0.9192. Furthermore, wavelet packet transform texture analysis is the optimal method, increasing the overall accuracy to 0.9216 using a smaller data dimension. Local spatial statistical measures also increase the classification total accuracy, but only from 0.7431 to 0.8088. This study demonstrates that wavelet packet and statistical textures can be used to improve object-oriented classification; specifically, the texture analysis based on the multiscale wavelet packet transform is optimal for increasing the classification accuracy using a smaller data dimension.     

An optimum feature extraction method for texture classification

Texture can be defined as a local statistical pattern of texture primitives in observer’s domain of interest. Texture classification aims to assign texture labels to unknown textures, according to training samples and classification rules. In this paper a novel method, which is an intelligent system for texture classification is introduced. It used a combination of genetic algorithm, discrete wavelet transform and neural network for optimum feature extraction from texture images. An algorithm called the intelligent system, which processes the pattern recognition approximation, is developed. We tested the proposed method with several texture images. The overall success rate is about 95%.     

一种新的基于纹理分水岭的纺织品缺陷检测方法

纺织品缺陷检测是纺织品自动检测的重要环节,而纺织品缺陷检测的目的是为了准确地对纺织品的缺陷区域进行定位.为了对纺织品缺陷进行准确有效的检测,提出了一种新的基于纹理分水岭的纺织品缺陷检测方法.该方法首先利用小波变换提取了图像的各子带纹理特征;然后对各子带纹理特征求梯度,并通过融合各子带梯度来获得纹理梯度,使其在纹理梯度中能有效地突出纹理区域的边界;最后在此基础上,结合分水岭分割,即能准确地检测出纺织品的缺陷区域.通过对一组6类纺织品缺陷进行检测的实验证明,该新算法是有效的.     

基于小波包分析的催化剂表面图象识别

二维图象可以通过小波分解来进行信号的多分辨率分析．本文讨论了小波包分析技术及其在催化剂表面ＳＥＭ图象识别上的应用．从小波包中抽取的能量和纹理熵特征，在催化剂的分类与识别研究中，充分描述了表面图象在多标度空间上的信息分布．实验结果表明，小波包分解树是一种很好的模式特征描述，为图象纹理识别提供了新的手段     

Log-polar wavelet energy signatures for rotation and scale invariant texture classification

Classification of texture images is important in image analysis and classification. This paper proposes an effective scheme for rotation and scale invariant texture classification using log-polar wavelet signatures. The rotation and scale invariant feature extraction for a given image involves applying a log-polar transform to eliminate the rotation and scale effects, but at same time produce a row shifted log-polar image, which is then passed to an adaptive row shift invariant wavelet packet transform to eliminate the row shift effects. So, the output wavelet coefficients are rotation and scale invariant. The adaptive row shift invariant wavelet packet transform is quite efficient with only O(n /spl middot/ log n) complexity. A feature vector of the most dominant log-polar wavelet energy signatures extracted from each subband of wavelet coefficients is constructed for rotation and scale invariant texture classification. In the experiments, we employed a Mahalanobis classifier to classify a set of 25 distinct natural textures selected from the Brodatz album. The experimental results, based on different testing data sets for images with different orientations and scales, show that the proposed classification scheme using log-polar wavelet signatures outperforms two other texture classification methods, its overall accuracy rate for joint rotation and scale invariance being 90.8 percent, demonstrating that the extracted energy signatures are effective rotation and scale invariant features. Concerning its robustness to noise, the classification scheme also performs better than the other methods.     

基于最小分类误差小波特征的纺织品缺陷分类方法研究

纺织品缺陷分类是利用计算机视觉技术检测纺织品品质的一个关键环节。提出了一种基于小波框架的纺织品缺陷分类新方法。该方法使用纺织品图像的小波框架来描述缺陷的纹理特征。在最小分类误差训练框架下,通过联合设计一个基于线性变换矩阵的特征提取器和一个分类器,来获取面向缺陷分类的小波框架特征,并最小化分类器的错误概率。该方法对包含9类纺织品缺陷的329个样本,以及328个无缺陷样本进行了分类实验评估,获得了931%的分类准确率,相比传统的基于小波变换的分类方法提高了272%。     

Discriminative training approaches to fabric defect classification based on wavelet transform

Wavelet transform is able to characterize the fabric texture at multiscale and multiorientation, which provides a promising way to the classification of fabric defects. For the objective of minimum error rate in the defect classification, this paper compares six wavelet transform-based classification methods, using different discriminative training approaches to the design of the feature extractor and classifier. These six classification methods are: methods of using an Euclidean distance classifier and a neural network classifier trained by maximum likelihood method and backpropagation algorithm, respectively; methods of using an Euclidean distance classifier and a neural network classifier trained by minimum classification error method, respectively; method of using a linear transformation matrix-based feature extractor and an Euclidean distance classifier, designed by discriminative feature extraction (DFE) method; method of using an adaptive wavelet-based feature extractor and an Euclidean distance classifier, designed by the DFE method. These six approaches have been evaluated on the classification of 466 defect samples containing eight classes of fabric defects, and 434 nondefect samples. The DFE training approach using adaptive wavelet has been shown to outperform the other approaches, where 95.8% classification accuracy was achieved.     

Texture classification using partial differential equation approach and wavelet transform

Textures and patterns are the distinguishing characteristics of objects. Texture classification plays fundamental role in computer vision and image processing applications. In this paper, texture classification using PDE (partial differential equation) approach and wavelet transform is presented. The proposed method uses wavelet transform to obtain the directional information of the image. A PDE for anisotropic diffusion is employed to obtain texture component of the image. The feature set is obtained by computing different statistical features from the texture component. The linear discriminant analysis (LDA) enhances separability of texture feature classes. The features obtained from LDA are class representatives. The proposed approach is experimented on three gray scale texture datasets: VisTex, Kylberg, and Oulu. The classification accuracy of the proposed method is evaluated using k-NN classifier. The experimental results show the effectiveness of the proposed method as compared to the other methods in the literature.     

基于小波包变换的模糊判决纹理分类

提出一种基于小波包变换的模糊判决纹理分类方法,采用图象的完全树结构小波变换提取多分辨率纹理特征,模糊判决分类器通过引入隶属度函数对待征模糊化,反映了各类纹理样本间存在的差异及随机噪声等畸变因素赞成的抽取特征值存在的不确定性,提高了纹理分类算法对噪声或畸变的鲁棒性,通过实验获得了较满意的结果。     

Comparison of wavelet families for texture classification by using wavelet packet entropy adaptive network based fuzzy inference system

Recently, significant of the robust texture image classification has increased. The texture image classification is used for many areas such as medicine image processing, radar image processing, etc. In this study, a new method for invariant pixel regions texture image classification is presented. Wavelet packet entropy adaptive network based fuzzy inference system (WPEANFIS) was developed for classification of the twenty 512 × 512 texture images obtained from Brodatz image album. There, sixty 32 × 32 image regions were randomly selected (overlapping or non-overlapping) from each of these 20 images. Thirty of these image regions and other 30 of these image regions are used for training and testing processing of the WPEANFIS, respectively. In this application study, Daubechies, biorthogonal, coiflets, and symlets wavelet families were used for wavelet packet transform part of the WPEANFIS algorithm, respectively. In this way, effects to correct texture classification performance of these wavelet families were compared. Efficiency of WPEANFIS developed method was tested and a mean %93.12 recognition success was obtained.     

基于复值小波包概率模型的纹理分类研究

为准确描述纹理,发挥复值小波包变换多方向通道等优点,首次基于复值小波包对纹理采用概率模型进行自适应描述,并同最大似然分类方法结合进行纹理分类.提出融合各类纹理最优描述的方法,将图库分类正确率从85%提高到93%.     

Texture classification using Gabor wavelets based rotation invariant features

Texture based image analysis techniques have been widely employed in the interpretation of earth cover images obtained using remote sensing techniques, seismic trace images, medical images and in query by content in large image data bases. The development in multi-resolution analysis such as wavelet transform leads to the development of adequate tools to characterize different scales of textures effectively. But, the wavelet transform lacks in its ability to decompose input image into multiple orientations and this limits their application to rotation invariant image analysis. This paper presents a new approach for rotation invariant texture classification using Gabor wavelets. Gabor wavelets are the mathematical model of visual cortical cells of mammalian brain and using this, an image can be decomposed into multiple scales and multiple orientations. The Gabor function has been recognized as a very useful tool in texture analysis, due to its optimal localization properties in both spatial and frequency domain and found widespread use in computer vision. Texture features are found by calculating the mean and variance of the Gabor filtered image. Rotation normalization is achieved by the circular shift of the feature elements, so that all images have the same dominant direction. The texture similarity measurement of the query image and the target image in the database is computed by minimum distance criterion.     

Texture classification and segmentation using wavelet packet frame and Gaussian mixture model

In this paper, we propose a scheme for texture classification and segmentation. The methodology involves an extraction of texture features using the wavelet packet frame decomposition. This is followed by a Gaussian-mixture-based classifier which assigns each pixel to the class. Each subnet of the classifier is modeled by a Gaussian mixture model and each texture image is assigned to the class to which pixels of the image most belong. This scheme shows high recognition accuracy in the classification of Brodatz texture images. It can also be expanded to an unsupervised texture segmentation using a Kullback-Leibler divergence between two Gaussian mixtures. The proposed method was successfully applied to Brodatz mosaic image segmentation and fabric defect detection.     

Texture segmentation using wavelet transform

Texture analysis such as segmentation and classification plays a vital role in computer vision and pattern recognition and is widely applied to many areas such as industrial automation, bio-medical image processing and remote sensing. This paper describes a novel technique of feature extraction for characterization and segmentation of texture at multiple scales based on block by block comparison of wavelet co-occurrence features. The performance of this segmentation algorithm is superior to traditional single resolution techniques such as texture spectrum, co-occurrences, local linear transforms, etc. The results of the proposed algorithm are found to be satisfactory.     

基于不完全树结构小波变换及模糊聚类神经网络的纹理分割

提出了一种新的不完全树结构小波变换用于纹理特征提取,给出了一种一人类视觉过程相一致的多分辨率多通道纹理分析方法,它由：1）特征提取：使用不完全树结构小波变换抽取纹理特征;2）基于模糊神经 网络的特征粗分类：①基于样本分布密度的模糊Kohonen聚类网络权植初始化,②使用缩减的特征向量对网络进行训练,得到粗分割结果;3）细化粗分割结果等几部分构成。实验结果证明了其有效性。