基于图像内容和噪音特征的扫描仪源辨识

以扫描仪获得的数字扫描图像为研究对象,提出一种基于图像内容和噪音特征的扫描仪源辨识方法,提取数字扫描图像中的颜色特征、质量特征和邻或预测特征,生成一个72维的特征向量以辨识扫描仪的来源,并借助支持向量机确定扫描仪的品牌或型号.实验结果表明,该方法具有较高的分类精度,并且在数字扫描图像被压缩或剪切的情况下均具有较好的鲁棒...     

Intrinsic Sensor Noise Features for Forensic Analysis on Scanners and Scanned Images

A large portion of digital images available today are acquired using digital cameras or scanners. While cameras provide digital reproduction of natural scenes, scanners are often used to capture hard-copy art in a more controlled environment. In this paper, new techniques for nonintrusive scanner forensics that utilize intrinsic sensor noise features are proposed to verify the source and integrity of digital scanned images. Scanning noise is analyzed from several aspects using only scanned image samples, including through image denoising, wavelet analysis, and neighborhood prediction, and then obtain statistical features from each characterization. Based on the proposed statistical features of scanning noise, a robust scanner identifier is constructed to determine the model/brand of the scanner used to capture a scanned image. Utilizing these noise features, we extend the scope of acquisition forensics to differentiating scanned images from camera-taken photographs and computer-generated graphics. The proposed noise features also enable tampering forensics to detect postprocessing operations on scanned images. Experimental results are presented to demonstrate the effectiveness of employing the proposed noise features for performing various forensic analysis on scanners and scanned images.      

Classification of complex environments using pixel level fusion of satellite data

The present study reports classification and analysis of composite land features using fusion images obtained by fusing two original hyperspectral and multispectral datasets. The high spatial-spectral resolution, multi-instrument and multi-period satellite images were used for fusion. Three pixel level fusion based techniques, Color Normalized Spectral Sharpening (CNSS), Principal Component Spectral Sharpening Transform (PCSST) and Gram-Schmidt Transform (GST), were implemented on the datasets. Performance evaluations of three fusion algorithms were done using classification results. The Support Vector Machine (SVM) and Gaussian Maximum Likelihood Classification (MLC) were used for classification using five types of images, viz. hyperspectral, multispectral and three fused images. Number of classes considered was eight. Sufficient number of ground field data for each class has also been acquired which was needed for supervise based classification. The accuracy was improved from 74.44 to 97.65% when the fused images were considered with SVM classifier. Similarly, the results were improved from 69.25 to 94.61% with original and fused data using MLC classifier. The fusion image technique was found to be superior to the single original image and the SVM is better than the MLC method.

     

双卷积池化结构的3D-CNN高光谱遥感影像分类方法

目的 高光谱遥感影像数据包含丰富的空间和光谱信息,但由于信号的高维特性、信息冗余、多种不确定性和地表覆盖的同物异谱及同谱异物现象,导致高光谱数据结构呈高度非线性。3D-CNN（3D convolutional neural network）能够利用高光谱遥感影像数据立方体的特性,实现光谱和空间信息融合,提取影像分类中重要的有判别力的特征。为此,提出了基于双卷积池化结构的3D-CNN高光谱遥感影像分类方法。方法 双卷积池化结构包括两个卷积层、两个BN（batch normalization）层和一个池化层,既考虑到高光谱遥感影像标签数据缺乏的问题,也考虑到高光谱影像高维特性和模型深度之间的平衡问题,模型充分利用空谱联合提供的语义信息,有利于提取小样本和高维特性的高光谱影像特征。基于双卷积池化结构的3D-CNN网络将没有经过特征处理的3D遥感影像作为输入数据,产生的深度学习分类器模型以端到端的方式训练,不需要做复杂的预处理,此外模型使用了BN和Dropout等正则化策略以避免过拟合现象。结果 实验对比了SVM（support vector machine）、SAE（stack autoencoder）以及目前主流的CNN方法,该模型在Indian Pines和Pavia University数据集上最高分别取得了99.65%和99.82%的总体分类精度,有效提高了高光谱遥感影像地物分类精度。结论 讨论了双卷积池化结构的数目、正则化策略、高光谱首层卷积的光谱采样步长、卷积核大小、相邻像素块大小和学习率等6个因素对实验结果的影响,本文提出的双卷积池化结构可以根据数据集特点进行组合复用,与其他深度学习模型相比,需要更少的参数,计算效率更高。     

3D卷积自编码器高光谱图像分类模型

目的 高光谱图像分类是遥感领域的基础问题，高光谱图像同时包含丰富的光谱信息和空间信息，传统模型难以充分利用两种信息之间的关联性，而以卷积神经网络为主的有监督深度学习模型需要大量标注数据，但标注数据难度大且成本高。针对现有模型的不足，本文提出了一种无监督范式下的高光谱图像空谱融合方法，建立了3D卷积自编码器（3D convolutional auto-encoder，3D-CAE）高光谱图像分类模型。方法 3D卷积自编码器由编码器、解码器和分类器构成。将高光谱数据预处理后，输入到编码器中进行无监督特征提取，得到一组特征图。编码器的网络结构为3个卷积块构成的3D卷积神经网络，卷积块中加入批归一化技术防止过拟合。解码器为逆向的编码器，将提取到的特征图重构为原始数据，用均方误差函数作为损失函数判断重构误差并使用Adam算法进行参数优化。分类器由3层全连接层组成，用于判别编码器提取到的特征。以3D-CNN （three dimensional convolutional neural network）为自编码器的主干网络可以充分利用高光谱图像的空间信息和光谱信息，做到空谱融合。以端到端的方式对模型进行训练可以省去复杂的特征工程和数据预处理，模型的鲁棒性和稳定性更强。结果 在Indian Pines、Salinas、Pavia University和Botswana等4个数据集上与7种传统单特征方法及深度学习方法进行了比较，本文方法均取得最优结果，总体分类精度分别为0.948 7、0.986 6、0.986 2和0.964 9。对比实验结果表明了空谱融合和无监督学习对于高光谱遥感图像分类的有效性。结论 本文模型充分利用了高光谱图像的光谱特征和空间特征，可以做到无监督特征提取，无需大量标注数据的同时分类精度高，是一种有效的高光谱图像分类方法。     

CNN和三维Gabor滤波器的高光谱图像分类

卷积神经网络(CNN)具有强大的特征提取能力,能够有效地提高高光谱图像的分类精度.然而CNN模型训练需要大量的训练样本参与,以防止过拟合,Gabor滤波器以非监督的方式提取图像的边缘和纹理等空间信息,能够减轻CNN模型对训练样本的依赖度及特征提取的压力.为了充分利用CNN和Gabor滤波器的优势,提出了一种双通道CNN和三维Gabor滤波器相结合的高光谱图像分类方法Gabor-DC-CNN.首先利用二维卷积神经网络(2D-CNN)模型处理原始高光谱图像数据,提取图像的深层空间特征;同时利用一维卷积神经网络(1D-CNN)模型处理三维Gabor特征数据,进一步提取图像的深层光谱-纹理特征.连接2个CNN模型的全连接层实现特征融合,并将融合特征输入到分类层中完成分类.实验结果表明,该方法能够有效地提高分类精度,在Indian Pines,Pavia University和Kennedy Space Center 3组数据上分别达到98.95%,99.56%和99.67%.     

基于统计特征和马尔可夫特征的图像拼接盲检测

数字图像真实性检测在司法鉴定等领域有着重要的作用.常见的图像拼接篡改会降低图像像素直接的相关性,这可以通过一些统计特征反映出来.采用特征提取-分类的方法,提取矩特征、基于二维相位一致性的统计特征,结合DCT域的马尔可夫特征,利用SVM分类器进行分类,实现了拼接图像的盲检测.实验结果表明,该方法有较好的鉴别准确率,可达91.75%.     

基于模式分类的图像区域作伪检测

为了鉴别一幅数字图像是否存在作伪的区域,提出一种利用改进的图像特征进行区域作伪检测的算法.基于模式分类的思想,该方法把图像分割成适当大小的块,从图像块中提取特征数据,用SVM分类器训练数据并得到支持向量机模型,利用该模型检测嫌疑图片是否存在作伪.该算法从噪声相关性、残差噪声、图像质量、小波域等方面分析相机图片的特点,获取每种的统计特征,形成特征集.实验结果表明,该方法能有效地检测出图像的具体作伪区域.     

Recognizing plankton images from the shadow image particle profiling evaluation recorder

We present a system to recognize underwater plankton images from the shadow image particle profiling evaluation recorder (SIPPER). The challenge of the SIPPER image set is that many images do not have clear contours. To address that, shape features that do not heavily depend on contour information were developed. A soft margin support vector machine (SVM) was used as the classifier. We developed a way to assign probability after multiclass SVM classification. Our approach achieved approximately 90% accuracy on a collection of plankton images. On another larger image set containing manually unidentifiable particles, it also provided 75.6% overall accuracy. The proposed approach was statistically significantly more accurate on the two data sets than a C4.5 decision tree and a cascade correlation neural network. The single SVM significantly outperformed ensembles of decision trees created by bagging and random forests on the smaller data set and was slightly better on the other data set. The 15-feature subset produced by our feature selection approach provided slightly better accuracy than using all 29 features. Our probability model gave us a reasonable rejection curve on the larger data set.     

基于张量分解的数字图像取证

提出一种基于张量分解的数字图像盲检测方法,从全局处理角度对JPEG压缩数字图像进行真伪盲检测。对于来自某一相机拍摄的一批参考图像组成的张量,利用张量分解的方法,从分解残差中分析提取图像特征,通过支持向量机分类器鉴别待检测图像是否直接来自该数码相机。实验结果表明,该方法对数字图像的来源鉴定具有较高准确性和较强的鲁棒性。     

Computer-aided evaluation of neuroblastoma on whole-slide histology images: Classifying grade of neuroblastic differentiation

Neuroblastoma (NB) is one of the most frequently occurring cancerous tumors in children. The current grading evaluations for patients with this disease require pathologists to identify certain morphological characteristics with microscopic examinations of tumor tissues. Thanks to the advent of modern digital scanners, it is now feasible to scan cross-section tissue specimens and acquire whole-slide digital images. As a result, computerized analysis of these images can generate key quantifiable parameters and assist pathologists with grading evaluations. In this study, image analysis techniques are applied to histological images of haematoxylin and eosin (H&E) stained slides for identifying image regions associated with different pathological components. Texture features derived from segmented components of tissues are extracted and processed by an automated classifier group trained with sample images with different grades of neuroblastic differentiation in a multi-resolution framework. The trained classification system is tested on 33 whole-slide tumor images. The resulting whole-slide classification accuracy produced by the computerized system is 87.88%. Therefore, the developed system is a promising tool to facilitate grading whole-slide images of NB biopsies with high throughput.     

基于CBP-TOP特征的人脸表情识别*

针对人脸表情时空域特征信息的有效提取,本文提出了一种CBP-TOP（Centralized Binary Patterns From Three Orthogonal Panels）特征和SVM分类器相结合的人脸表情识别新方法。该方法首先将原始图像序列进行图像预处理,包括人脸检测、图像截取和图像尺度归一化,然后用CBP-TOP算子对图像序列进行分块提取特征,最后采用SVM分类器进行表情识别。实验结果表明,该方法能更有效提取图像序列的运动特征和动态纹理信息,提高了表情识别的准确率。和VLBP特征相比, CBP-TOP特征在表情识别中具有更高的识别率和更快的识别速度。     

基于HOG和SVM的双眼虹膜图像的人眼定位算法

针对近红外光下现有的人眼定位算法普遍存在准确性不高、泛化能力不佳等问题，提出了一种基于方向梯度直方图（HOG）和支持向量机（SVM）相结合的双眼虹膜图像的人眼定位算法。利用HOG提取虹膜图像的人眼特征，并结合SVM分类器对HOG特征进行训练从而实现人眼的精确定位。为了减少漏检和误检，进一步提高定位准确率，又提出了多级级联SVM分类器算法；另外针对近红外光线下虹膜图像独特的灰度分布特点，设计了一种图像预处理方法，能够显著提高人眼定位速度。在MIR2016和CASIA-IRIS-Distance数据集上的实验结果表明，基于HOG和SVM的双眼虹膜图像的人眼定位算法具有高准确率、强泛化能力和高实时性。     

基于改进CNN-SVM的甲烷传感器数显识别方法

甲烷传感器材质存在光反射,显示面板上有附着物,造成甲烷传感器自动检定系统采集的传感器数值图像质量较差,对字符识别困难。而现有的基于机器学习的仪表字符识别方法识别率较低、算法运行速度较慢。针对上述问题,提出了一种基于改进卷积神经网络(CNN)-支持向量机(SVM)的甲烷传感器数显识别方法。通过图像增强、数值区域图像提取、图像分割、小数点定位等4个步骤对甲烷传感器数值图像进行预处理,并将处理后的数字图像作为自定义数据集。针对CNN-SVM模型运行时间较长的问题,使用PCA算法对CNN全连接层提取的图像特征进行降维处理,用最主要数据特征代替原始数据作为SVM分类器的样本进行分类识别。在自建数据集上的验证结果表明,与传统CNN模型和CNN-SVM模型相比,改进CNN-SVM模型的准确率更高,运行时间更短。在经典MNIST数据集上的验证结果表明,综合考虑精度和实时性要求,改进CNN-SVM模型的综合性能优于CRNN,SSD,YOLOv3,Faster R-CNN等模型。采用微型高清USB摄像头采集甲烷传感器数值图像,将训练好的改进CNN-SVM模型移植到树莓派中进行图像处理和识别,结果表明,基于改进CNN-SVM的甲烷传感器数显识别方法的识别成功率为99%,与仿真分析结果一致。     

A novel SVM-based handwritten Tamil character recognition system

This paper describes a system for recognizing offline handwritten Tamil characters using support vector machine (SVM). Data samples are collected from different writers on A4 sized documents. They are scanned using a flat bed scanner at a resolution of 300 dpi and stored as gray-scale images. Various preprocessing operations are performed on the digitized image to enhance the quality of the image. Pixel densities are calculated for 64 different zones of the image and these values are used as the features of a character. These features are used to train the SVM. The SVM is tested for the first time to recognize handwritten Tamil characters. The system has achieved a very good recognition accuracy of 82.04% on the handwritten Tamil character database.     

Classify vehicles in traffic scene images with deformable part-based models

Vehicle classification is an important and challenging task in intelligent transportation systems, which has a wide range of applications. In this paper, we propose to integrate vehicle detection and vehicle classification into one single framework by using deformable part-based models. First of all, we use annotated vehicle images to train a deformable part-based model for each class of vehicles to be classified. Then, given a traffic scene image, we employ the obtained vehicle models to perform vehicle detection in it for vehicle extraction. After that, model alignment is performed on the extracted image crop, based on which features are extracted for creating a representation for the vehicle in the given image. We train a linear multi-class Support Vector Machine classifier based on representations of images in a validation set. Finally, we adopt the SVM classifier for vehicle classification. The proposed method is evaluated on the BIT-Vehicle Dataset, and can achieve an accuracy of \(91.08\%\), which is superior to methods used for comparison. Obtained results demonstrated the effectiveness of the proposed method.     

Camera model identification using a deep network and a reduced edge dataset

Today, the importance of digital images as a medium for social communication is growing rapidly. Sometimes, an image needs to be authenticated by verifying its source camera model or device. Recently, deep networks have become very successful at visual pattern recognition. With this motivation, several investigators have explored the possibility of using convolutional neural networks (CNNs) for camera source identification. In this paper, we use selective preprocessing, instead of a indiscriminate one, in order not to hinder the CNN’s strong ability to learn useful features for this kind of forensic task. To generate a consistent and balanced dataset, we limit the maximum number of original images to 200 per camera model, and we discard vertically taken images. Using a relatively simple deep network structure, the proposed method achieved a better prediction accuracy—95.0%—than GoogleNet and other existing methods. Also, challenging camera models such as the Sony DSC H50 and W170 can be classified with the quite high prediction accuracies of 87.9% and 83.1%, respectively.

     

基于改进的SVM的甲状腺图像检索

针对SVM处理大数据量和区分训练集样本属性的重要性差的问题,我们将SVM和粗糙集结合,构造了基于粗糙集与SVM的图像检索相关反馈算法,将其应用于甲状腺CT图像检索。实验结果表明,改进的SVM分类精度可达到92.53%,相比SVM的分类精度(76.58%)提高了15.95%,进而使检索的查准率和查全率也分别提高到89.53%和29.67%。     

基于多特征和改进SVM集成的图像分类

现有图像分类方法不能充分利用图像各单一特征之间的优势互补特性,提取的特征中存在大量冗余信息,从而导致图像分类精度不高。为此,提出一种基于多特征和改进支持向量机(SVM)集成的图像分类方法。该方法能提取全面描述图像内容的综合特征,采用主成分分析对所提取的特征进行变换,去除冗余信息,使用支持向量机的集成分类器RBaggSVM进行分类。仿真实验结果表明,与同类图像分类方法相比,该方法具有更高的图像分类精度和更快的分类速度。     

Pattern recognition techniques for automatic detection of suspicious-looking anomalies in mammograms

We have employed two pattern recognition methods used commonly for face recognition in order to analyse digital mammograms. The methods are based on novel classification schemes, the AdaBoost and the support vector machines (SVM). A number of tests have been carried out to evaluate the accuracy of these two algorithms under different circumstances. Results for the AdaBoost classifier method are promising, especially for classifying mass-type lesions. In the best case the algorithm achieved accuracy of 76% for all lesion types and 90% for masses only. The SVM based algorithm did not perform as well. In order to achieve a higher accuracy for this method, we should choose image features that are better suited for analysing digital mammograms than the currently used ones.