- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Color medical image lossless watermarking using chaotic system and accurate quaternion polar harmonic transforms
摘要： With the increasingly widespread use of medical images in medical institutions and networks, the copyright protection of medical images has become increasingly urgent. Since traditional embedded watermarking technology degrades the quality of the original images, it is not suitable for medical images. In addition, most medical watermarking algorithms are aimed at grayscale images; therefore, a smaller number of color medical image watermarking algorithms are available. In this paper, we propose a lossless watermarking scheme for color medical image copyright protection based on a chaotic system and quaternion polar harmonic transforms (QPHTs), which is a quaternion orthogonal moment method. In watermark embedding, we compute the QPHTs for the original color medical image and select accurate coefficients to construct a zero-watermark image. Then, the zero-watermark image is stored in the intellectual property right (IPR) database. Experimental results show that the proposed scheme is robust to geometric attacks and common attacks and that it has better performance than similar lossless watermarking schemes. In addition, this paper details the selection of accurate coefficients for QPHTs and compares stability with different choices of unit pure quaternions.
关键词： mixed linear-nonlinear coupled map lattice,geometric attacks,chaotic system,quaternion polar harmonic transforms,lossless watermarking,color medical image
更新于2025-09-10 09:29:36
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Coulomb explosion imaging of CH <sub/>3</sub> I and CH <sub/>2</sub> ClI photodissociation dynamics
摘要： The photodissociation dynamics of CH3I and CH2ClI at 272 nm were investigated by time-resolved Coulomb explosion imaging, with an intense non-resonant 815 nm probe pulse. Fragment ion momenta over a wide m/z range were recorded simultaneously by coupling a velocity map imaging spectrometer with a pixel imaging mass spectrometry camera. For both molecules, delay-dependent pump-probe features were assigned to ultraviolet-induced carbon-iodine bond cleavage followed by Coulomb explosion. Multi-mass imaging also allowed the sequential cleavage of both carbon-halogen bonds in CH2ClI to be investigated. Furthermore, delay-dependent relative fragment momenta of a pair of ions were directly determined using recoil-frame covariance analysis. These results are complementary to conventional velocity map imaging experiments and demonstrate the application of time-resolved Coulomb explosion imaging to photoinduced real-time molecular motion.
关键词： pixel imaging mass spectrometry,time-resolved,CH3I,velocity map imaging,photodissociation dynamics,Coulomb explosion imaging,CH2ClI
更新于2025-09-10 09:29:36
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[IEEE 2018 International Conference on Communication and Signal Processing (ICCSP) - Chennai, India (2018.4.3-2018.4.5)] 2018 International Conference on Communication and Signal Processing (ICCSP) - Comparative Analysis of Image Encryption Using 2D and 3D Variations of Duffing Map
摘要： In current era, security of digital image during the transaction is more important. For this reason, chaotic maps are highly used. In this paper, image encryption technique is used in gray image and color image using 2D and 3D Duffing map. This technique works on scrambling of pixels where encryption and decryption process are associated with the key. Further, we analyzed security of image encryption techniques with two parameters called NPCR and UACI. The effectiveness of the encryption process can be seen in experimental results.
关键词： 2D Duffing Map,Decryption,Encryption,Security,Chaotic Map,3D Duffing Map
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 28th International Workshop on Machine Learning for Signal Processing (MLSP) - Aalborg, Denmark (2018.9.17-2018.9.20)] 2018 IEEE 28th International Workshop on Machine Learning for Signal Processing (MLSP) - LIGHT FIELD BASED FACE RECOGNITION VIA A FUSED DEEP REPRESENTATION
摘要： The emergence of light field cameras opens new frontiers in terms of biometric recognition. This paper proposes the first deep CNN solution for light field based face recognition, exploiting the richer information available in a lenslet light field image. Additionally, for the first time, the exploitation of disparity maps together with 2D-RGB images and depth maps has been considered in the context of the face recognition a fusion scheme performance. The proposed solution uses the 2D-RGB central sub-aperture view as well as the disparity and depth maps extracted from the full set of sub-aperture images associated to a lenslet light field. After, feature extraction is performed using a VGG-Face deep descriptor for texture and independently fine-tuned models for disparity and depth maps. Finally, the extracted features are concatenated to be fed into an SVM classifier. A comprehensive set of experiments has been conducted with the IST-EURECOM light field face database, showing the superior performance of the fused deep representation for varied and challenging recognition tasks.
关键词： Disparity Map,Face Recognition,Depth Map,Lenslet Light Field Imaging,Fine-Tuning,VGG-Face Descriptor
更新于2025-09-09 09:28:46
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Image encryption algorithm based on quantum chaotic map and DNA coding
摘要： With the rapid development of network and information technology, people are paying more attention to the security of information, particularly digital image protection, and numerous image encryption algorithms have been proposed. Because of the non-periodicity and sensitivity to the initial value, chaotic map seems to be a tool that can be used for image encryption. Recent work has shown that the quantum chaotic map is very sensitive to a slight change in the initial conditions. The sensitivity of the quantum chaotic map can extremely increase the complexity of the encryption algorithms. At present, a wide variety of image encryption algorithms based on DNA encoding have been proposed, where the image pixel values are encoded by four base pairs of DNA to achieve image pixel diffusion, but most of the methods in selecting the DNA encoding rules are fixed. In this paper, we present a new image encryption algorithm with the quantum chaotic map, the Lorenz chaotic map and DNA coding, which uses four base pairs of DNA dynamically select eight types of DNA encoding rules and eight types of DNA addition and XOR rules. This strategy has led to a significant enhancement in reliability and security. Through simulation experiments, the results of the histograms, correlations and the number of pixels change rate (NPCR) analyses indicate that the proposed algorithm possesses a high level of security and can successfully resist different attacks such as brute-force attacks and statistical attacks.
关键词： Quantum chaotic map,DNA coding,Image encryption,Lorenz chaotic map
更新于2025-09-09 09:28:46
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A FRET sensor for live-cell imaging of MAP kinase activity in Arabidopsis
摘要： The catalytic activity of mitogen activated protein kinases (MAPKs) is dynamically modified in plants. Since MAPKs have been shown to play important roles in a wide range of signaling pathways, the ability to monitor MAPK activity in living plant cells would be valuable. Here we report the development of a genetically encoded MAPK activity sensor for use in Arabidopsis thaliana. The sensor is composed of yellow and blue fluorescent proteins, a phosphopeptide binding domain, a MAPK substrate domain, and a flexible linker. Using in vitro testing, we demonstrated that phosphorylation causes an increase in the F?rster resonance energy transfer (FRET) efficiency of the sensor. FRET efficiency can therefore serve as a readout of kinase activity. We also produced transgenic Arabidopsis lines expressing this sensor of MAPK activity (SOMA) and performed live-cell imaging experiments using detached cotyledons. Treatment with NaCl, the synthetic flagellin peptide flg22, and chitin all led to rapid gains in FRET efficiency. Control lines expressing a version of SOMA in which the phosphosite was mutated to an alanine did not show any substantial FRET changes. We also expressed the sensor in a conditional loss-of function double-mutant line for the Arabidopsis MAPK genes MPK3 and MPK6. These experiments demonstrated that MPK3/6 are necessary for the sensor’s NaCl-induced FRET gain, while other MAPKs are likely contributing to the chitin and flg22-induced FRET increases. Taken together, our results suggest that SOMA is able to dynamically report MAPK activity in living plant cells.
关键词： Arabidopsis thaliana,FRET sensor,live-cell imaging,MAP kinase
更新于2025-09-09 09:28:46
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[Lecture Notes in Electrical Engineering] Microelectronics, Electromagnetics and Telecommunications Volume 521 (Proceedings of the Fourth ICMEET 2018) || Extraction of Lesion and Tumor Region in Multi-modal Images Using Novel Self-organizing Map-Based Enhanced Fuzzy C-Means Clustering Algorithm
摘要： Analyzing the medical images and segmenting the same for detecting the tumor and lesion regions embedded within the images are quite a tedious process. On performing the task of tumor and lesion region detection, several intricacies arise and two of the major hindrances are time complexity and accuracy level sustainment. Resolving these two issues is the major concern of this paper and the authors have achieved it, which could be veri?ed from the ?gures of this paper. If the examination of the medical images obtained through modalities such as MRI and CT is clearly processed using an algorithm, preplanning of surgical procedures could be made with ease. The development of such an algorithm is focused by the authors, and the algorithm framed in this research ensemble the working of self-organizing map (SOM) and enhanced fuzzy C-means (EnFCM), and the authors have collectively named the algorithm as SOM-based EnFCM. The proposed algorithm has produced a high peak signal-to-noise ratio (PSNR) value of 60 dB and mean square error (MSE) of 0.06. The time required by the algorithm for processing 71 input slice images acquired through CT and MRI scans is around 6 s, and the overall accuracy exhibited by the algorithm is 48%. This has given a new and a dynamic approach, which could be greatly used by the radiologists in clinical practices. To contest and prove the ef?ciency of the SOM–EnFCM algorithm, the segmentation results of SOM and EnFCM algorithms while operating individually are compared.
关键词： Tumor identi?cation,Self-organized map algorithm,Enhanced fuzzy C-means algorithm,Tissue segmentation
更新于2025-09-09 09:28:46
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[IEEE 2017 International Conference on 3D Vision (3DV) - Qingdao (2017.10.10-2017.10.12)] 2017 International Conference on 3D Vision (3DV) - Spatial Maps: From Low Rank Spectral to Sparse Spatial Functional Representations
摘要： Functional representation is a well-established approach to represent dense correspondences between deformable shapes. The approach provides an efficient low rank representation of a continuous mapping between two shapes, however under that framework the correspondences are only intrinsically captured, which implies that the induced map is not guaranteed to map the whole surface, much less to form a continuous mapping. In this work, we define a novel approach to the computation of a continuous bijective map between two surfaces moving from the low rank spectral representation to a sparse spatial representation. Key to this is the observation that continuity and smoothness of the optimal map induces structure both on the spectral and the spatial domain, the former providing effective low rank approximations, while the latter exhibiting strong sparsity and locality that can be used in the solution of large-scale problems. We cast our approach in terms of the functional transfer through a fuzzy map between shapes satisfying infinitesimal mass transportation at each point. The result is that, not only the spatial map induces a sub-vertex correspondence between the surfaces, but also the transportation of the whole surface, and thus the bijectivity of the induced map is assured. The performance of the proposed method is assessed on several popular benchmarks.
关键词： Functional representation,dense correspondences,continuous bijective map,deformable shapes,sparse spatial representation,low rank spectral representation
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE International Conference on Information Communication and Signal Processing (ICICSP) - Singapore, Singapore (2018.9.28-2018.9.30)] 2018 IEEE International Conference on Information Communication and Signal Processing (ICICSP) - A Highly Secure Digital Image Steganography Technique Using Chaotic Logistic Map and Support Image
摘要： A widely applied technique to transmit secret information, hiding in a cover image is Least Significant Bit (LSB) image steganography. Various stega-analysis algorithms are available to detect the amount of hidden data in such cover image. Nonlinear chaotic map functions which are highly complex in behaviour with unpredictable time evolution are used for designing security algorithms. In this paper we report a highly secure steganography technique using chaotic map and a support image to hide secret information in a grayscale cover image. The secret information is encrypted before hiding and the support image is pre-processed to defy stega-analysis. Our three prong security technique applies to secret information by using a very robust random sequence for encryption, a support grayscale image, and pre-processing of the support image.
关键词： Hyper-chaotic system,Chaotic logistic map,Steganography
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - The Accurate Estimation of Disparity Maps from Cross-Scale Reference-Based Light Field
摘要： This paper addresses the problem of disparity map accurate estimation in the cross-scale reference-based light ?eld, which consists several low-quality images arranged around one central high-resolution (HR) image. In the framework, we use a HR image-guidance CNN (HRIG-CNN) for estimating the disparity map in the HR level. Speci?cally, we ?rst calculate the coarse disparity map using our cross-pattern strategy, which can blend the multiple disparity maps. And then, we re?ne this coarse disparity map using HRIG-CNN for obtaining high-quality disparity map, which contains detail information and preserve edge information. With the HR image guidance, our HRIG-CNN achieves state-of-the-art for obtaining disparity map in such hybrid light ?eld condition. In the end, we provide both quantitative and qualitative evaluations on different methods, and demonstrate the high performance and robustness of the proposed framework compared with the state-of-the-arts algorithms.
关键词： super-resolution,computational imaging,light field,disparity map,cross-scale resolution
更新于2025-09-09 09:28:46