- 标题
- 摘要
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- 实验方案
- 产品
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[ACM Press the 2018 International Conference - Porto, Portugal (2018.07.15-2018.07.17)] Proceedings of the 2018 International Conference on Mathematics and Statistics - ICoMS 2018 - Singular Value Decomposition and its Applications in Image Processing
摘要： The Singular Value Decomposition (SVD) is a highlight of linear algebra and has a wide range application in computer vision, statistics and machine learning. This paper reviews the main theorem of SVD and illustrates some applications of SVD in image processing. More specifically, we focus on image compression and matrix completion. The former is to convert the original full-rank pixel matrix to a well-approximated low-rank matrix and thus dramatically save the space, the latter is to recover a pixel matrix with a large number of missing entries by using nuclear norm minimization, in which some singular value thresholding algorithm will be used. For both applications, we conduct numerical experiments to show the performance and point out some possible improvements in the future.
关键词： Nuclear norm minimization,Matrix completion,Image compression,SVD
更新于2025-09-23 15:22:29
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Sparse Reconstruction-Based Thermal Imaging for Defect Detection
摘要： This paper proposes an idea of employing sparse reconstruction-based technique for thermal imaging defect detection. The implementation of the reconstruction technique is tested on a carbon fiber reinforced polymer test piece with artificially drilled defects and the test results are compared with the established cross correlation method. The two processes are compared in terms of defect detectability, their SNR variation with defect depth and their computation complexity. When compared with cross correlation algorithm, the technique is expected to solve memory space problems by compressing all information from large cross-correlated pulse video into a single reconstructed image as an output. Furthermore, in existing cross correlation methods, the pulse peak time shifts with defect depth. Hence, defect quantification algorithms, such as SNR calculation, require multiple frame analysis. Such algorithms are comparatively simplified in sparse reconstruction technique. This paper explores sparse reconstruction algorithm for resolving close-spaced defects. This paper further describes cross-validation method for optimization of a user parameter in sparse reconstruction method.
关键词： thermal nondestructive testing,sparse reconstruction,pulse compression,nondestructive evaluation and remote sensing,frequency modulated thermal wave imaging,Cross correlation algorithm
更新于2025-09-23 15:22:29
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - Velocity Estimation for Moving Target Refocusing in the Long-Time Coherent Integration SAR Imaging
摘要： A novel procedure is proposed to estimate the two-dimensional (2-D) velocity parameters of moving targets from single-channel synthetic aperture radar (SAR) data in a long-time coherent integration for motion compensation. First, the SAR data is divided into several sub-band data by sub-aperture decomposition, since target motion may be changing in the whole long-time aperture, so that the velocity estimation for each sub-band can be performed respectively. Then, the range walk correction is carried out via Doppler centroid analysis based motion estimation and compensation, by which the energy of the moving target is concentrated into a single range cell. This processing is especially advantageous to the following exact Doppler parameter estimation. Finally, the fine 2-D motion parameters are estimated based on mismatched compression simultaneously. Compared to conventional algorithms with a time-consuming searching process, the 2-D velocity estimation of moving targets can be carried out using this algorithm more efficiently, and the SAR image can be well focused and right located after further motion compensation. Experimental results for numerically simulated SAR images demonstrate the effectiveness of the proposed technique.
关键词： doppler centroid analysis,synthetic aperture radar (SAR),refocusing,mismatched compression,velocity estimation
更新于2025-09-23 15:22:29
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Mechanically Enhanced Electrical Conductivity of Polydimethylsiloxane-Based Composites by a Hot Embossing Process
摘要： Electrically conductive polymer composites are in high demand for modern technologies, however, the intrinsic brittleness of conducting conjugated polymers and the moderate electrical conductivity of engineering polymer/carbon composites have highly constrained their applications. In this work, super high electrical conductive polymer composites were produced by a novel hot embossing design. The polydimethylsiloxane (PDMS) composites containing short carbon fiber (SCF) exhibited an electrical percolation threshold at 0.45 wt % and reached a saturated electrical conductivity of 49 S/m at 8 wt % of SCF. When reducing the sample thickness from 1.0 to 0.1 mm by the hot embossing process, a compression-induced percolation threshold occurred at 0.3 wt %, while the electrical conductivity was further enhanced to 378 S/m at 8 wt % SCF. Furthermore, the addition of a second nanofiller of 1 wt %, such as carbon nanotube or conducting carbon black, further increased the electrical conductivity of the PDMS/SCF (8 wt %) composites to 909 S/m and 657 S/m, respectively. The synergy of the densified conducting filler network by the mechanical compression and the hierarchical micro-/nano-scale filler approach has realized super high electrically conductive, yet mechanically flexible, polymer composites for modern flexible electronics applications.
关键词： compression-induced percolation threshold,synergy,electrical conducting network,hybrid filler,forced assembly
更新于2025-09-23 15:22:29
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Vector quantization using the improved differential evolution algorithm for image compression
摘要： Vector quantization (VQ) is a popular image compression technique with a simple decoding architecture and high compression ratio. Codebook designing is the most essential part in vector quantization. Linde–Buzo–Gray (LBG) is a traditional method of generation of VQ codebook which results in lower PSNR value. A codebook affects the quality of image compression, so the choice of an appropriate codebook is a must. Several optimization techniques have been proposed for global codebook generation to enhance the quality of image compression. In this paper, a novel algorithm called IDE-LBG is proposed which uses improved differential evolution algorithm coupled with LBG for generating optimum VQ codebooks. The proposed IDE works better than the traditional DE with modifications in the scaling factor and the boundary control mechanism. The IDE generates better solutions by efficient exploration and exploitation of the search space. Then the best optimal solution obtained by the IDE is provided as the initial codebook for the LBG. This approach produces an efficient codebook with less computational time and the consequences include excellent PSNR values and superior quality reconstructed images. It is observed that the proposed IDE-LBG find better VQ Codebooks as compared to IPSO-LBG, BA-LBG and FA-LBG.
关键词： Improved differential evolution (IDE) algorithm,Improved particle swarm optimization (IPSO) algorithm,Bat algorithm (BA),Firefly algorithm (FA),Vector quantization,Image compression,Codebook,Linde–Buzo–Gray (LBG) algorithm
更新于2025-09-23 15:22:29
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GPU Acceleration of Clustered DPCM for Lossless Compression of Hyperspectral Images
摘要： With the development of remote sensing technology, spatial and spectral resolutions of hyperspectral images have become increasingly dense. In order to overcome difficulties in the storage, transmission and manipulation of hyperspectral images, an effective compression algorithm is requisite. The Clustered Differential Pulse Code Modulation (C-DPCM), which is a prediction-based hyperspectral lossless compression algorithm, can achieve a relatively high compression ratio, but its efficiency still requires improvement. This paper presents a parallel implementation of the C-DPCM algorithm on Graphics Processing Units (GPUs) with the Compute Unified Device Architecture (CUDA), which is a parallel computing platform and programming model developed by NVIDIA. Three optimization strategies are utilized to implement the C-DPCM algorithm in parallel, including a version that uses shared memory and registers, a version that employs multi-stream, and a version that uses multi-GPU. In addition, we studied how to assign all classes to each GPU to minimize the processing time. Finally, we reduced the compression time from approximately half an hour to an hour to several seconds, with almost no loss in accuracy.
关键词： C-DPCM,GPU,CUDA,Hyperspectral image lossless compression
更新于2025-09-23 15:22:29
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[IEEE 2018 XV International Scientific Conference on Optoelectronic and Electronic Sensors (COE) - Warsaw, Poland (2018.6.17-2018.6.20)] 2018 XV International Scientific Conference on Optoelectronic and Electronic Sensors (COE) - Microsystems for Cell Deformability Measurements
摘要： This paper presents a new technical solution in the form of MEMS-type deformation microcytometer and a new methodology for determining the deformability of animal oocytes. As a reference method compression of the oocyte with commercial micromanipulator will be descried and compared with proposed solution. Preliminary results showing the deformation of porcine oocytes will be presented using both methods to validate the work of the microcytometer.
关键词： mechanical properties of cells,microfluidics,compression and indentation of the cell,deformability of oocytes,microcytometry,microsystem
更新于2025-09-23 15:22:29
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Coulomb interaction-induced jitter amplification in RF-compressed high-brightness electron source ultrafast electron diffraction
摘要： We have theoretically and experimentally demonstrated an RF compression-based jitter-amplification effect in high-brightness electron source ultrafast electron diffraction (UED), which degrades the temporal resolution significantly. A detailed analysis and simulations reveal the crucial role of the longitudinal and transverse Coulomb interaction for this jitter-amplification effect, which accord very well with experimental results. An optimized compact UED structure for full compression has been proposed, which can suppress the jitter by half and improve the temporal resolution to sub-100 fs. This Coulomb interaction-induced jitter amplification exists in nearly the whole ultrafast physics field where laser-electron synchronization is required. Moreover, it cannot be suppressed completely. The quantified explanation for the mechanism and optimization provides important guidance for photocathode accelerators and other compression-based ultrashort electron pulse generation and precise control.
关键词： system optimization,jitter amplification,RF compression,high-brightness electron source,ultrafast electron diffraction,Coulomb interaction
更新于2025-09-23 15:21:21
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Compression of Hyperspectral Images Using Luminance Transform and 3D-DCT
摘要： DCT based transform techniques are popular in image compression. In this paper, luminance transform is applied to improve the compression performance of 3-D discrete cosine transform (3D-DCT) in hyperspectral images. The proposed scheme consists of two main steps. Firstly, luminance transform is performed on spectral band groups taking the first band image in a group as the reference. The aim of using luminance transform is to reduce the brightness and contrast difference within spectral band groups. Secondly, compression is performed by 3D-DCT followed by entropy encoding. The performance of the proposed approach is compared to 3D-DCT in terms of signal-to-noise ratio (SNR) and mean spectral angle (MSA). It is observed that applying luminance transform before 3D-DCT provides better results especially at low bit-rates.
关键词： hyperspectral image compression,luminance transform,3D-DCT
更新于2025-09-23 15:21:21
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Comparative appraisal of global and local thresholding methods for binarisation of off-axis digital holograms
摘要： Binary digital and computer-generated holograms are used in a number of digital micromirror device (DMD) applications, including holographic displays, media characterisation, optical encryption, and others. Binarisation is one of the most simple and e?cient methods of hologram compression. In this paper, 12 local and 18 global thresholding techniques of di?erent groups were analysed and compared based on attribute similarity, clustering, entropy, histogram shape, and local adaptive factors. Optically recorded o?-axis digital holograms of di?erent objects were binarised using these methods. The amplitude quality of the obtained reconstructed images was compared using PSNR and SSIM values. The clustering-based methods achieved the highest quality. The results of binarisation by global and local methods were comparable on average.
关键词： Image binarisation,Hologram compression,Thresholding,Digital holography,Digital image processing,Digital micromirror device
更新于2025-09-23 15:21:21