An Efficient Detection Approach of Content Aware Image Resizing

Content aware image resizing (CAIR) is an excellent technology used widely for image retarget. It can also be used to tamper with images and bring the trust crisis of image content to the public. Once an image is processed by CAIR, the correlation of local neighborhood pixels will be destructive. Although local binary patterns (LBP) can effectively describe the local texture, it however cannot describe the magnitude information of local neighborhood pixels and is also vulnerable to noise. Therefore, to deal with the detection of CAIR, a novel forensic method based on improved local ternary patterns (ILTP) feature and gradient energy feature (GEF) is proposed in this paper. Firstly, the adaptive threshold of the original local ternary patterns (LTP) operator is improved, and the ILTP operator is used to describe the change of correlation among local neighborhood pixels caused by CAIR. Secondly, the histogram features of ILTP and the gradient energy features are extracted from the candidate image for CAIR forgery detection. Then, the ILTP features and the gradient energy features are concatenated into the combined features, and the combined features are used to train classifier. Finally support vector machine (SVM) is exploited as a classifier to be trained and tested by the above features in order to distinguish whether an image is subjected to CAIR or not. The candidate images are extracted from uncompressed color image database (UCID), then the training and testing sets are created. The experimental results with many test images show that the proposed method can detect CAIR tampering effectively, and that its performance is improved compared with other methods. It can achieve a better performance than the state-of-the-art approaches.     

A colour image retrieval scheme based on Z-scanning technique

Abstract

This paper proposes a new colour image retrieval scheme using Z-scanning technique for content-based image retrieval (CBIR). In recent years, the CBIR is a popular research topic for image retrieval. This paper proposes a scheme which employs the Z-scanning technique to extract directional intensity features for measuring the similarity between query and database images. In the multiple channel images, each colour channel can be processed individually or combined into a grey channel Y. In order to extract the features by Z-scanning technique from all images, each channel of all images must be divided into several N×N blocks. In each block, F pairs of pixels are scanned by a ‘Z’ direction to obtain the texture features. Each colour channel can be obtained an M×M Z-scanning co-occurrence matrix (ZSCM) for storing the probability of each relationship of all closest blocks. At the similarity measure stage, the ZSCMs of query image and database images are compared to measure their similarity. The experimental results show that the proposed scheme is beneficial for image retrieval when the images include the same texture or object. On the other hand, the proposed scheme also can get better retrieval results and more efficiency than colour correlogram (CC) technique for colour texture images. Another technique uses motif co-occurrence matrix (MCM) as the feature in similarity measurement. The experimental results show the proposed ZSCM can get better retrieval results and higher recall and precision values than the CC and MCM techniques for public image databases.     

非负矩阵分解耦合视觉词典的图像检索算法

目的解决当前图像检索技术中,图像特征稀疏编码收敛速度慢,以及局部特征空间信息不足易导致检索误差较大等问题,提出一种基于l0稀疏约束非负矩阵分解耦合视觉词典优化的图像检索算法。方法首先,在非负矩阵分解(Non-negative Matrix Factorization,NMF)的基础上,对系数矩阵设置l0个约束来限制其稀疏性,从而定义一种l0稀疏约束的NMF方法。再通过一种自适应序列词典初始化方案,从训练样本获得词典的初始估计。然后,利用l0稀疏约束的NMF来增强视觉词典,对图像局部描述符进行稀疏编码,并利用最大池化操作来生成聚合特征向量,从而保留局部描述符的关键属性。最后根据得到的特征向量,引入Minkowski距离来衡量查询图像与数据库的相似性,输出检索图像。结果实验结果表明,与当前图像检索方案相比,所提算法具有更高的查准-查全率和收敛速度。结论所提算法返回的图像与查询图像相似度高,在包装商标检索等领域具有一定的参考价值。     

基于压缩量化与邻域空间LBP算子的图像哈希算法

目的为了解决哈希算法的感知鲁棒性与伪造检测能力不高的问题,提出基于特征压缩机制与邻域空间局部二值模式的紧凑图像哈希算法。方法首先利用2D线性插值技术,对输入图像进行预处理;嵌入Ring分割技术,将其变为二次图像;再利用Gabor滤波技术对其完成过滤;考虑到图像的颜色特征与其内在的空间关系,基于局部二值模式LBP设计邻域空间LBP算子,提取滤波图像的特征;构建特征压缩量化准则,输出紧凑的哈希二值数组;迭代Logistic映射,输出随机序列,通过量化每个序列值输出密钥流,通过构建动态引擎设计分段异加密模型,实现紧凑哈希序列的加密,获取图像哈希;最后计算原始哈希序列与待检测哈希序列的Hamming距离,实现图像信息的安全认证。结果与已有的哈希生成机制相比,文中算法所输出的哈希序列更紧凑,对旋转、伽马校正等篡改操作具有更好的感知鲁棒。结论所提哈希技术具备较高的安全性,在包装图标检索、信息检测等领域具有较好的价值。     

CANFIS based glioma brain tumor classification and retrieval system for tumor diagnosis

Brain tumor classification and retrieval system plays an important role in medical field. In this paper, an efficient Glioma Brain Tumor detection and its retrieval system is proposed. The proposed methodology consists of two modules as classification and retrieval. The classification modules are designed using preprocessing, feature extraction and tumor detection techniques using Co‐Active Adaptive Neuro Fuzzy Inference System (CANFIS) classifier. The image enhancement can be achieved using Heuristic histogram equalization technique as preprocessing and further texture features as Local Ternary Pattern (LTP) features and Grey Level Co‐occurrence Matrix (GLCM) features are extracted from the enhanced image. These features are used to classify the brain image into normal and abnormal using CANFIS classifier. The tumor region in abnormal brain image is segmented using normalized graph cut segmentation algorithm. The retrieval module is used to retrieve the similar segmented tumor regions from the dataset for diagnosing the tumor region using Euclidean algorithm. The proposed Glioma Brain tumor classification methodology achieves 97.28% sensitivity, 98.16% specificity and 99.14% accuracy. The proposed retrieval system achieves 97.29% precision and 98.16% recall rate with respect to ground truth images.     

基于ScSPM-Reranking的高分辨率遥感影像的检索

为了从高分辨率遥感影像中获取详细的地表地物信息,为城市规划、环境监测以及灾情分析提供可靠的数据,进行了高分辨率遥感影像的检索研究,包括对图像的特征提取和图像之间相似度的描述。为了提高图像检索精度,运用了采用稀疏编码(Sc)的空间塔式匹配(Sc SPM)技术和重排序(Reranking)技术,提出了基于Sc SPM结合Reranking(ScSPM-Reranking)的遥感高分辨率影像的检索方法。该方法首先使用Sc SPM提取空间场景的特征,然后结合这些特征使用cityblock距离进行初步检索,最后对初步检索的结果进行Reranking排序,获得高精度的检索结果。同其他检索方法进行了对比实验,实验结果证明,该方法具有较高的检索精度。     

综合PHOG和LWT的图像检索算法

目的研究物体的形状特征在图像描述及图像检索中的区分度和检索性能。方法设计一种综合PHOG形状和提升小波变换的图像检索算法。算法首先对原始图像进行极坐标系方向归一化,提取图像旋转不变特征;其次提取分层图像的PHOG形状特征;然后提取分层图像低频变换系数均值和方差作为提升小波变换特征;最后将各种特征进行融合并用于图像检索,并定义距离衡量公式。结果通过文中设计算法提取的图像形状特征可使各标准测试图像间距离均值为0.2352。结论在Corel图像集上的检索实验结果优于RIM算法和FWTH算法,表明文中算法图像检索领域具有一定的应用前景。     

基于字典统计耦合归一化多重距离的图像检索算法

目的针对当前彩色图像检索技术容易受到色彩的干扰,使其鲁棒性不强等不足,提出一种字典统计耦合归一化多重距离的彩色图像检索算法。方法首先将图像量化并转换成一维信号,然后引入字典统计,将一维信号进行字典编码,并计算编码后的图像多样值,在归一化字典距离的基础上嵌入字典编码图像的多样值,从而定义归一化多重距离(NMD)的相似度量准则,利用NMD对查询图像与数据库图像的多样值进行比较与识别,搜索出与查询图像具有相同特征的最相似图像,完成目标检索。结果在COREL数据库的实验结果表明,相对于当前常用的检索技术,该检索算法具有更高的查准率和查全率,可对彩色图像完成精确检索,有效减低了色彩对检索性能的干扰。结论文中算法具有较好的检索精度,能够较好地用于医疗、商标等领域的目标检索。     

An Efficient Steganalysis Model Based on Multi-Scale LTP and Derivative Filters

Local binary pattern (LBP) is one of the most advanced image classification recognition operators and is commonly used in texture detection area. Research indicates that LBP also has a good application prospect in steganalysis. However, the existing LBP-based steganalysis algorithms are only capable to detect the least significant bit (LSB) and the least significant bit matching (LSBM) algorithms. To solve this problem, this paper proposes a steganalysis model called msdeLTP, which is based on multi-scale local ternary patterns (LTP) and derivative filters. The main characteristics of the msdeLTP are as follows: First, to reduce the interference of image content on features, the msdeLTP uses derivative filters to acquire residual images on which subsequent operations are based. Second, instead of LBP features, LTP features are extracted considering that the LTP feature can exhibit multiple variations in the relationship of adjacent pixels. Third, LTP features with multiple scales and modes are combined to show the relationship of neighbor pixels within different radius and along different directions. Analysis and simulation show that the msdeLTP uses only 2592-dimensional features and has similar detection accuracy as the spatial rich model (SRM) at the same time, showing the high steganalysis efficiency of the method.     

无下采样轮廓波变换纹理图像检索系统

针对基本轮廓波变换纹理检索系统检索率较低的问题,提出了一种无下采样轮廓波变换(NSCT)纹理图像检索系统.该系统采用的轮廓波变换由无下采样拉普拉斯金字塔级联无下采样方向滤波器构成,特征向量采用子带系数的能量和标准偏差连接而成;以Canberra距离为相似度度量标准.比较了基于同样架构的基本轮廓波变换和NSCT纹理检索系统的性能.实验结果表明:在特征向量长度,检索时间、所需存储空间基本相同的情况下,NSCT检索系统比基本轮廓波变换检索系统具有更高的检索率;NSCT分解结构参数以及图像类型对于平均检索率也有较大的影响.     

基于包装外观特征图像内容检索方法研究

针对包装外观特征图像信息在图像数据特征的表述、图像内容的检索方法上进行了阐述,并对图像中的颜色特征、纹理特征、轮廓特征进行了表述分析,以便于图像特征的提取和图像内容的匹配,从而实现图像内容的检索,为图像数据库的储存、检索、处理提供相应的处理技术。     

基于深度学习耦合稀疏语义度量的商标检索算法

目的针对当前商标图像检索中的语义鸿沟问题,提出一种深度学习耦合稀疏语义度量的商标图像检索方案,有效抑制噪声干扰,降低冗余特征维数。方法首先,根据由卷积与池化组成的无监督学习机制,对输入商标图像进行多层特征提取,输出一维特征向量。随后,通过L2-支持向量机(L2-SVM)进行分类,利用特征向量进行训练,获得多级联特征。然后,根据商标图像的多级联特征和用户标签信息的异构数据结构,设计一种稀疏语义度量方法进行相似检索,减少语义鸿沟。此外,引入一种混合范数作为相似度量的稀疏约束,以抑制原始输入空间中的冗余特征维数和噪声,优化检索结果。结果实验表明,与当前流行的商标检索方案相比,所提算法具有更高的检索精度,其输出的结果中仅有1幅无关图像。结论该方案具有较高的检索精度和较强的鲁棒性,在商标检测、商标保护等方面中具有良好的应用价值。     

A Cryptograph Domain Image Retrieval Method Based on Paillier Homomorphic Block Encryption

With the rapid development of information network, the computing resources and storage capacity of ordinary users cannot meet their needs of data processing. The emergence of cloud computing solves this problem but brings data security problems. How to manage and retrieve ciphertext data effectively becomes a challenging problem. To these problems, a new image retrieval method in ciphertext domain by block image encrypting based on Paillier homomophic cryptosystem is proposed in this paper. This can be described as follows: According to the Paillier encryption technology, the image owner encrypts the original image in blocks, obtains the image in ciphertext domain, then passes it to the third party server. The server calculates the difference histogram of the image in ciphertext domain according to the public key and establishes the index database. The user passes the retrieved image to the server. The server computes the differential histogram of the retrieved image by public key. Then, compares the similarity of it with the histogram in index database and selects larger similarity images in ciphertext and send them to the user. The user obtains the target image with the private key. The experimental results show that the method is feasible and simple.     

Multi-Index Image Retrieval Hash Algorithm Based on Multi-View Feature Coding

In recent years, with the massive growth of image data, how to match the image required by users quickly and efficiently becomes a challenge. Compared with single-view feature, multi-view feature is more accurate to describe image information. The advantages of hash method in reducing data storage and improving efficiency also make us study how to effectively apply to large-scale image retrieval. In this paper, a hash algorithm of multi-index image retrieval based on multi-view feature coding is proposed. By learning the data correlation between different views, this algorithm uses multi-view data with deeper level image semantics to achieve better retrieval results. This algorithm uses a quantitative hash method to generate binary sequences, and uses the hash code generated by the association features to construct database inverted index files, so as to reduce the memory burden and promote the efficient matching. In order to reduce the matching error of hash code and ensure the retrieval accuracy, this algorithm uses inverted multi-index structure instead of single-index structure. Compared with other advanced image retrieval method, this method has better retrieval performance.     

基于区域生长耦合多分类器的商标检索算法

目的针对商标检索算法中易出现的语义鸿沟,底层视觉特征与高层语义相关性不强而导致商标检索精度不理想的问题,定义一种基于区域生长耦合多分类器的商标检索方案。方法首先对输入的商标进行预处理,去除图像中的噪声和杂散点,并通过3D直方图和聚类算法来提取输入图像中的主颜色;基于区域生长算法,合并具有相同颜色标签的所有连接点,以形成颜色区域;然后根据生成的颜色区域,分别定义颜色分类器、形状分类器和关系分类器,利用每个分类器计算查询图像和数据库中图像的检索优势概率;最后通过决策组合,根据检索规则和列表长度找到最相似的商标,并利用动态选择方案进一步提高检索准确率。结果实验结果表明,与当前商标检索方案相比,所提检索系统具有更为理想的Precision-Recall曲线,对缩放、扭曲和噪声具有更高的鲁棒性。结论所提方案在各类几何变换下具备较高的检索准确率,对商标注册、版权保护等行业有较好的借鉴意义。     

Optical image encryption using password key based on phase retrieval algorithm

A novel optical image encryption system is proposed using password key based on phase retrieval algorithm (PRA). In the encryption process, a shared image is taken as a symmetric key and the plaintext is encoded into the phase-only mask based on the iterative PRA. The linear relationship between the plaintext and ciphertext is broken using the password key, which can resist the known plaintext attack. The symmetric key and the retrieved phase are imported into the input plane and Fourier plane of 4f system during the decryption, respectively, so as to obtain the plaintext on the CCD. Finally, we analyse the key space of the password key, and the results show that the proposed scheme can resist a brute force attack due to the flexibility of the password key.     

Perceptual image hashing using local entropies and DWT

Abstract

Image hashing is an emerging technology in multimedia security. It uses a short string called image hash to represent an input image and finds applications in image authentication, tamper detection, digital watermark, image indexing, content-based image retrieval and image copy detection. This paper presents a hashing algorithm based on the observation that block entropies are approximately linearly changed after content-preserving manipulations. This is done by converting the input image to a fixed size, dividing the normalised image into non-overlapping blocks, extracting entropies of image blocks and applying a single-level 2D discrete wavelet transform to perform feature compression. Correlation coefficient is exploited to evaluate similarity between hashes. Experimental results show that the proposed algorithm is robust against content-preserving operations, such as JPEG compression, watermark embedding, Gamma correction, Gaussian low-pass filtering, adjustments of brightness and contrast, scaling and small angle rotation. Similarity values between hashes of different images are small, indicating good performances in discriminative capability.     

基于感兴趣区域的图像检索方法

为了弥补全局特征在描述图像内容上的不足，近年来许多研究者提出了基于区域的图像表示和检索方法。本文提出了一种基于感兴趣区域的图像检索方法，根据认知心理学中选取注视焦点的模型来提取感兴趣区域，利用感兴趣区域的视觉特征和位置关系进行图像检索。该方法既利用了区域的局部特征，又考虑了区域在重要程度上的差别。在60000幅通用图像库上的实验结果表明，这种方法的检索效率要好于现有的基于区域的方法，而义对查询图像的噪声等扰动具有鲁棒性。     

A content-based image retrieval system based on object-moment feature

The last decade has witnessed great interest in research on content-based image retrieval (CBIR). In 2009, Lin et al. proposed a smart CBIR system based on colour and texture feature. Their system has a high detection rate except the cases where image objects have similar shapes. To enhance the detection rate a shape-based image feature called object-moment is proposed in this paper. Object-moment uses the moment of force to compute the object edge feature by calculating the distance from each edge pixel to the axis, and adding them up as a feature. Besides, we integrate the colour features (NSOM, CSOM) and the texture features (CCM, DBPSP) to enhance image detection rate and simplify computation of image retrieval. A series of analyses and comparisons are performed in our experiments to demonstrate that our proposed method improves the retrieval accuracy significantly.     

An Encrypted Image Retrieval Method Based on SimHash in Cloud Computing

With the massive growth of images data and the rise of cloud computing that can provide cheap storage space and convenient access, more and more users store data in cloud server. However, how to quickly query the expected data with privacy-preserving is still a challenging in the encryption image data retrieval. Towards this goal, this paper proposes a ciphertext image retrieval method based on SimHash in cloud computing. Firstly, we extract local feature of images, and then cluster the features by K-means. Based on it, the visual word codebook is introduced to represent feature information of images, which hashes the codebook to the corresponding fingerprint. Finally, the image feature vector is generated by SimHash searchable encryption feature algorithm for similarity retrieval. Extensive experiments on two public datasets validate the effectiveness of our method. Besides, the proposed method outperforms one popular searchable encryption, and the results are competitive to the state-of-the-art.