An incremental neural network for tissue segmentation in ultrasound images

This paper presents an incremental neural network (INeN) for the segmentation of tissues in ultrasound images. The performances of the INeN and the Kohonen network are investigated for ultrasound image segmentation. The elements of the feature vectors are individually formed by using discrete Fourier transform (DFT) and discrete cosine transform (DCT). The training set formed from blocks of 4x4 pixels (regions of interest, ROIs) on five different tissues designated by an expert is used for the training of the Kohonen network. The training set of the INeN is formed from randomly selected ROIs of 4x4 pixels in the image. Performances of both 2D-DFT and 2D-DCT are comparatively examined for the segmentation of ultrasound images.     

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。     

Medical image segmentation with transform and moment based features and incremental supervised neural network

In this study, a novel incremental supervised neural network (ISNN) is proposed for the segmentation of medical images. Performance of the ISNN is investigated for tissue segmentation in medical images obtained from various imaging modalities. Two feature extraction methods based on transform and moments are comparatively investigated to segment the tissues in medical images. Two-dimensional (2D) continuous wavelet transform (CWT) and the moments of the gray-level histogram (MGH) are computed in order to form the feature vectors of ultrasound (US) bladder and phantom images, X-ray computerized tomography (CT) and magnetic resonance (MR) head images. In the 2D-CWT method, feature vectors are formed by the intensity of one pixel of each wavelet-plane of different energy bands. The MGH represents the tissues within the sub-windows by using the spatial variation of image intensities. In this study, the ISNN and Grow and Learn (GAL) network are employed for the segmentation task. It is observed that the ISNN has significantly eliminated the disadvantages of the GAL network in the segmentation of the medical images.     

Segmentation of MR and CT Images by Using a Quantiser Neural Network

A Quantiser Neural Network (QNN) is proposed for the segmentation of MR and CT images. Elements of a feature vector are formed by image intensities at one neighbourhood of the pixel of interest. QNN is a novel neural network structure, which is trained by genetic algorithms. Each node in the first layer of the QNN forms a hyperplane (HP) in the input space. There is a constraint on the HPs in a QNN. The HP is represented by only one parameter in d-dimensional input space. Genetic algorithms are used to find the optimum values of the parameters which represent these nodes. The novel neural network is comparatively examined with a multilayer perceptron and a Kohonen network for the segmentation of MR and CT head images. It is observed that the QNN gives the best classification performance with fewer nodes after a short training time.     

Application of InP Neural Network to ECG BeatClassification

This paper presents an application of a hybrid neural network structure to the classification of the electrocardiogram (ECG) beats. Three different feature extraction methods are comparatively examined: discrete cosine transform, wavelet transform and a direct method. Classification performances, training times and the numbers of nodes of Kohonen network, Restricted Coulomb Energy (RCE) network and the hybrid neural network are presented. To increase the classification performance and to decrease the number of nodes, the hybrid neural network is trained by Genetic Algorithms (GAs). Ten types of ECG beats obtained from the MIT-BIH database and from a real-time ECG measurement system are classified with a success of 98% by using the hybrid neural network structure and discrete cosine transform together.     

基于小波和余弦变换的神经网络人脸识别法

提出了利用小波变换和余弦变换与 BP 神经网络相结合的人脸识别方法。将人脸图像归一化后进行小波变换,再用余弦变换对低频信号提取特征向量,达到降维和去除干扰的目的,并把特征向量送进 BP 神经网络训练。识别时,对人脸图像进行相同的变换后,送入神经网络进行辨别。实验结果表明,该算法优于传统的人脸识别法。     

Computer-aided diagnosis of human brain tumor through MRI: A survey and a new algorithm

Computer-aided detection/diagnosis (CAD) systems can enhance the diagnostic capabilities of physicians and reduce the time required for accurate diagnosis. The objective of this paper is to review the recent published segmentation and classification techniques and their state-of-the-art for the human brain magnetic resonance images (MRI). The review reveals the CAD systems of human brain MRI images are still an open problem. In the light of this review we proposed a hybrid intelligent machine learning technique for computer-aided detection system for automatic detection of brain tumor through magnetic resonance images. The proposed technique is based on the following computational methods; the feedback pulse-coupled neural network for image segmentation, the discrete wavelet transform for features extraction, the principal component analysis for reducing the dimensionality of the wavelet coefficients, and the feed forward back-propagation neural network to classify inputs into normal or abnormal. The experiments were carried out on 101 images consisting of 14 normal and 87 abnormal (malignant and benign tumors) from a real human brain MRI dataset. The classification accuracy on both training and test images is 99% which was significantly good. Moreover, the proposed technique demonstrates its effectiveness compared with the other machine learning recently published techniques. The results revealed that the proposed hybrid approach is accurate and fast and robust. Finally, possible future directions are suggested.     

遗传算法优化小波神经网络的网络流量预测

为了提高网络流量的预测精度,克服小波神经网络收敛速度慢、易陷入局部最优的缺点,提出一种遗传算法优化小波神经网络的网络流量预测模型.首先计算延迟时间和嵌入维数,构建小波神经网络的学习样本,然后采用小波神经网络对网络流训练集进行学习,并采用改进遗传算法对小波神经网络参数进行全局寻优,提高收敛速度和网络学习精度,最后采用网络流量数据对模型性能进行仿真分析.结果表明,相对于对比模型,本文模型的平均误差大幅度降低,训练次数急剧减,减小了二次优化训练的次数,具有更大的实际应用价值.     

Segmentation of ultrasound images by using a hybrid neural network

A hybrid neural network is presented for the segmentation of ultrasound images.

Feature vectors are formed by the discrete cosine transform of pixel intensities in region of interest (ROI). The elements and the dimension of the feature vectors are determined by considering only two parameters: The amount of ignored coefficients, and the dimension of the ROI.

First-layer-nodes of the proposed hybrid network represent hyperspheres (HSs) in the feature space. Feature space is partitioned by intersecting these HSs to represent the distribution of classes. The locations and radii of the HSs are found by the genetic algorithms.

Restricted Coulomb energy (RCE) network, modified RCE network, multi-layer perceptron and the proposed hybrid neural network are examined comparatively for the segmentation of ultrasound images.     

织物表面折皱的小波分析与自组织神经网络等级评定

为了提取较为精细的图像信息，引入了多尺度2维小波分析织物的表面折皱。织物图像首先经过高斯滤波，再利用小波变换分解并从中提取高频信息，然后结合4种表征织物折皱的特征参数，计算不同折皱等级模板的特征值，通过分析特征值与折皱等级的相关系数，表明这4种特征参数可以作为模式识别的输入量；最后采用Kohonen自组织神经网络客观评定织物的折皱等级，自组织神经网络将不同等级的织物折皱模板进行分类，并以此为依据，确定26种不同织物类型的折皱等级。为了定量描述评定结果，通过计算客观评定与主观评定结果的相关系数，验证该方法的可行性。     

结合特定理论工具的彩色图像分割技术

由于彩色图像提供了比灰度图像更为丰富的信息,因此彩色图像处理正受到人们越来越多的关注。彩色图像分割是彩色图像处理的重要问题,目前对彩色图像的分割已提出了许多种算法。对近年来通过结合模糊技术、马尔可夫随机场、神经网络、遗传算法、小波变换等特定理论工具和模型的彩色图像分割方法和策略加以介绍。     

基于Kohonen网络的小波阈值在遥感图像去噪中的应用研究

传统Donoho非线性小波阈值去噪方法中,阈值的选取一般是根据噪声方差设置的,但在实际的操作中很难对噪声方差的精确值,这种理论上的局限性使得各种基于方差估计的去噪方法并不能获得实际需要的去噪结果;针对阈值选取的问题,提出一种非线性小波变换阈值的kohonen神经网络的自调整学习训练方法对遥感图像进行去噪,该方法在小波变换的基础上结合了神经网络的非线性阈值自组织特征映射算法,阈值的选择根据训练图像进行学习;可以实现自调整寻找最优值,以满足实际,达到最优的去噪效果。     

基于改进遗传算法的小波神经网络控制器的研究

小波神经网络是一种引入小波分析理论的前馈型神经网络,其与遗传算法的结合可以得到一种拥有良好全局优化搜索和良好局部时频特性的学习训练途径。本文提出了一种基于改进遗传算法的小波神经网络控制器,此方法可以克服基本遗传算法收敛速度慢,容易陷入＂早熟＂收敛,计算稳定性不好等一系列问题,进一步提高了小波神经网络控制器的性能。最后通过二级倒立摆仿真和实物控制,证明了控制器的有效性。     

Segmentation of multispectral MR images through an annealed rough neural network

In this paper, multispectral image segmentation using a rough neural network based on an annealed strategy with a cooling schedule is created. The main purpose is to embed an annealed cooling schedule into the rough neural network to construct a segmentation system named annealed rough neural net (ARNN). The classification system is a paradigm for the implementation of annealed reasoning and rough systems in neural network architecture. Instead of all the information in the image are fed into the neural network, the upper- and lower-bound gray level, captured from a training vector in a multispectral image, were fed into a rough neuron in the ARNN. Therefore, only 2-channel images are selected as the training samples if an N-dimensional multispectral image was used. In the simulation results, the proposed network not only reduces the consuming time but also reserves the classification performance.     

A cluster-based wavelet feature extraction method and its application

In this paper, a new cluster-based approach is proposed for extracting features from the coefficients of a two-dimensional discrete wavelet transform. The wavelet coefficients from the matrix of each frequency channel are segregated into non-overlapping clusters in an unsupervised mode using a set of application-specific representative images. In practical situations, this set of representative images can be the same as the ones kept aside for training a classifier. The proposed method divides the matrices of computed wavelet coefficients into disjoint clusters that are centered around the position of dominant coefficients. The features that can distinguish images of one class from those of other classes are obtained by computing energies of the clusters. The feature vectors so obtained are then presented as input patterns to an image classifier, such as a neural network. Experimental results based on the applications for texture classification and wood surface defect detection have shown that the proposed cluster-based wavelet feature extraction method is able to effectively extract important intrinsic information content from the test images, and increase the overall classification accuracy as compared with conventional feature extraction methods.     

轴承故障融合诊断方法

针对传统人工神经网络在故障诊断中应用的局限性 ,提出一种基于小波变换、遗传算法与神经网络的融合故障诊断方法。该方法先用小波变换对原始采样信号进行特征提取 ,再用遗传算法优化选择最为重要的特征作为神经网络的输入参数。最后 ,由神经网络进行状态识别和特征分类。这样不仅减少网络训练时间 ,降低网络计算量 ,而且有效提高分类的准确性及故障诊断的可靠性。轴承故障诊断实验结果表明 ,该方法是有效的。     

Segmentation of MR and CT Images Using a Hybrid Neural Network Trained by Genetic Algorithms

A novel hybrid neural network trained by the genetic algorithms is presented. Genetic algorithms are used to improve the neural net's classification performance while minimizing the number of nodes. Each node of the network forms a closed region in the input space. The closed regions, which are formed by the nodes, intersect each other. The performance of the proposed hybrid neural network is compared with the multilayer perceptron, and the restricted Coulomb energy network for the segmentation of MR and CT head images. Experimental results show that the proposed neural network gives the best classification performance with a small number of nodes in short training times.     

深层聚合残差密集网络的超声图像左心室分割

目的 超声图像是临床医学中应用最广泛的医学图像之一,但左心室超声图像一般具有强噪声、弱边缘和组织结构复杂等问题,其图像分割难度较大。临床上需要一种效率高、质量好的超声图像左心室分割算法。本文提出一种基于深层聚合残差密集网络（deep layer aggregation for residual dense network,DLA-RDNet）的超声图像左心室分割算法。方法 对获取的超声图像进行形态学操作,定位目标区域,得到目标图像。构建残差密集网络（residual dense network,RDNet）用于提取图像特征,并将RDNet得到的层次信息通过深层聚合（deep layer aggregation,DLA）的方式紧密融合到一起,得到分割网络DLA-RDNet,用于实现对超声图像左心室的精确分割。通过深监督（deep supervision,DS）方式为网络剪枝,简化网络结构,提升网络运行速度。结果 数据测试集的实验结果表明,所提算法平均准确率为95.68%,平均交并比为97.13%,平均相似性系数为97.15%,平均垂直距离为0.31 mm,分割轮廓合格率为99.32%。与6种分割算法相比,所提算法的分割精度更高。在测试阶段,每幅图像仅需不到1 s的时间即可完成分割,远远超出了专业医生的分割速度。结论 提出了一种深层聚合残差密集神经网络对超声图像左心室进行分割,通过主、客观对比实验表明本文算法的有效性,能够较对比方法更实时准确地对超声图像左心室进行分割,符合临床医学中超声图像左心室分割的需求。     

Wavelet-based image interpolation using multilayer perceptrons

Changing the resolution of digital images and video is needed image processing systems. In this paper, we present nonlinear interpolation schemes for still image resolution enhancement. The proposed neural network interpolation method is based on wavelet reconstruction. With the wavelet decomposition, the image signals can be divided into several time–frequency portions. In this work, the wavelet decomposition signal is used to train the neural networks. The pixels in the low-resolution image are used as the input signal of the neural network to estimate all the wavelet sub-images of the corresponding high-resolution image. The image of increased resolution is finally produced by the synthesis procedure of wavelet transform. In the simulation, the proposed method obtains much better performance than other traditional methods. Moreover, the easy implementation and high flexibility of the proposed algorithm also make it applicable to various other related problems.     

A novel method of short-term load forecasting based on multiwavelet transform and multiple neural networks

This paper aims to develop a load forecasting method for short-term load forecasting based on multiwavelet transform and multiple neural networks. Firstly, a variable weight combination load forecasting model for power load is proposed and discussed. Secondly, the training data are extracted from power load data through multiwavelet transform. Lastly, the obtained data are trained through a variable weight combination model. BP network, RBF network and wavelet neural network are adopted as the training network, and the trained data from three neural networks are input to a three-layer feedforward neural network for the load forecasting. Simulation results show that accuracy of the combination load forecasting model proposed in the paper is higher than any one single network model and the combination forecast model of three neural networks without preprocessing method of multiwavelet transform.