- 标题
- 摘要
- 关键词
- 实验方案
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Multichannel image contrast enhancement based on linguistic rule-based intensificators
摘要： This study follows the direct approach to image contrast enhancement, which changes the image contrast at each its pixel and is more effective than the indirect approach that deals with image histograms. However, there are only few studies following the direct approach because, by its nature, it is very complex. Additionally, it is difficult to develop an effective method since it is required to keep a balance in maintaining local and global image features while changing the contrast at each individual pixel. Moreover, raw images obtained from many sources randomly influenced by many external factors can be considered as fuzzy uncertain data. In this context, we propose a novel method to apply and immediately handle expert fuzzy linguistic knowledge of image contrast enhancement to simulate human capability in using natural language. The formalism developed in the study is based on hedge algebras considered as a theory, which can immediately handle linguistic words of variables. This allows the proposed method to produce an image contrast intensificator from a given expert linguistic rule base. A technique to preserve global as well as local image features is proposed based on a fuzzy clustering method, which is applied for the first time in this field to reveal region image features of raw images. The projections of the obtained clusters on each channel are suitably aggregated to produce a new channel image considered as input of the pixelwise defined operators proposed in this study. Many experiments are performed to demonstrate the effect of the proposed method versus the counterparts considered.
关键词： interpolation inference method,contrast measurement,image contrast enhancement,hedge algebra,linguistic rule-based knowledge
更新于2025-09-23 15:23:52
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[IEEE 2018 15th Conference on Computer and Robot Vision (CRV) - Toronto, ON, Canada (2018.5.8-2018.5.10)] 2018 15th Conference on Computer and Robot Vision (CRV) - Multi-projector Resolution Enhancement Through Biased Interpolation
摘要： Projecting the same content with multiple overlapping projectors provides several advantages compared to using a single projector: increased brightness to overcome ambient light or projection surface anomalies, redundancy in case of projector failure, an increase in the area being projected on, and the possibility for increased content resolution. Multi-projector resolution enhancement is the process of using multiple projectors to achieve a resolution greater than any individual projector in the configuration. Current resolution enhancement techniques perform filtering on the sub-images produced by each projector using spatial or frequency based filters. The kernel based filtering adds significant overhead relative to the interpolation calculations. In addition the learned filters are extremely sensitive to calibration. This work develops a method for performing multi-projector resolution enhancement by integrating the filtering into the interpolation process. A system is developed to jointly condition multiple low resolution sub-images on each other to approximate high resolution original content.
关键词： structural similarity,resolution enhancement,biased interpolation,multi-projector
更新于2025-09-23 15:23:52
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Digital Image Interpolation in MATLAB? || Covariance-Based Interpolation
摘要： The previous chapter has shown the importance of maintaining the image edges in image interpolation to obtain a natural-looking interpolated image. We have discussed the basic structure and model of image edges. The multi-resolution analysis presented in the chapter on wavelet (Chapter 6) has shown that an ideal step edge obeys the geometric regularity property [43], which refers to the correlation structure of an ideal step edge being independent of the scale of the image. In other words, the correlation structure of the local region that has enclosed an edge feature in the low-resolution image should have a similar correlation structure in the corresponding region in the high-resolution image. The edge-directed interpolated algorithms presented in the last chapter aim to preserve the correlation structures across scales by estimating the unknown pixels with the consideration of the locations and orientations of the image edges. The locations and the orientations of the image edges are specified by explicit edge map obtained through some kind of edge detection techniques. There are several problems associated with such approach. Firstly, the edge detection technique quantized the edge orientation in finite number of cases. As a result, the interpolation results can only preserve limited classes of correlation structures during the interpolation process. In other words, the geometric regularity cannot be fully preserved between the low-resolution image and the interpolated high-resolution image. Secondly, the edge detection algorithm has detection accuracy problems in both the spatial location of the edge pixel and the orientation of the associated edge. As a result, the edge-directed interpolation algorithm might falsely preserve a nonexisting edge structure and results in image artifacts with unnatural appearance and low in peak signal-to-noise ratio (PSNR). To achieve good image interpolation result, the geometric regularity property should be fully exploited. Various algorithms have been proposed in literature that aim to preserve the geometric regularity between the low-resolution image and the interpolated high-resolution image, which include directly considering the geometric regularity in spatial domain [12, 38], reformulating the problem into a set of partial differential equations [6, 47], and constructing a convex set of geometric regularity [54], and proposed a projection-onto-convex-set algorithm to achieve an interpolated image with the best matched correlation structure between the low-resolution image and the interpolated high-resolution image.
关键词： geometric regularity,MATLAB,edge-directed interpolation,NEDI,covariance-based interpolation,image interpolation
更新于2025-09-23 15:22:29
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[IEEE 2018 25th International Conference on Mechatronics and Machine Vision in Practice (M2VIP) - Stuttgart, Germany (2018.11.20-2018.11.22)] 2018 25th International Conference on Mechatronics and Machine Vision in Practice (M2VIP) - Generative models for direct generation of CNC toolpaths
摘要： Today, numerical controls (CNC) are the standard for the control of machine tools and industrial robots in production and enable highly flexible and efficient production, especially for frequently changing production tasks. A numerical control has discrete inputs and outputs. Within the NC channel, however, it is necessary to analytically describe curves for the calculation of the position setpoints and the jerk limitation. The resulting change between discrete and continuous description forms and the considerable restrictions in the parallelisation of the interpolation of continuous curves within the NC channel lead to a performance overhead that limits the performance of the NC channel with regard to the calculation of new position setpoints. This can lead to a drop in production speed and thus to longer production times. To solve this problem, we propose a new approach in this paper. This is based on the use of deep generative models and allows the direct generation of interpolated toolpaths without calculation of continuous curves and subsequent discretization. The generative models are being trained to create curves of certain types such as linear and parabolic curves or splines directly as discrete point sequences. This approach is very well feasible with regard to its parallelization and reduces the computing effort within the NC channel. First results with straight lines and parabolic curves show the feasibility of this new approach for the generation of CNC toolpaths.
关键词： machine learning,computerized numerical control,interpolation,CNC,generative adversarial networks
更新于2025-09-23 15:22:29
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[IEEE 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Paris, France (2018.10.14-2018.10.17)] 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Calculation of Degradation Rates of Poly Crystalline Si and CIGS PV Module using Outdoor Linear Interpolation Method
摘要： We propose the method to calculate the degradation rate of PV modules by outdoor linear interpolation method (LIM). Since the reference I-V curves which are based on measured I-V curves and used to LIM are created in each season, transitions of expected I-V curves indicate how PV modules degrade. The degradation rates of not only the maximum power but also the other parameters such as short circuit current and open circuit voltage can be calculated from the expected I-V curves. In this paper, the outdoor degradation rates of poly crystalline Si and CIGS were calculated. As a result, in poly crystalline Si case, the degradation rate of maximum power was calculated as -0.4 %/year due to short circuit current reduction. In CIGS case, although the initial power generation performance was better than the datasheet value, the annual degradation rate of the maximum power was calculated as -2.1 %/year. The reason of maximum power reduction was the reduction of both short-circuit current and open-circuit voltage.
关键词： photovoltaic module,CIGS,poly crystalline silicon,degradation,linear interpolation method
更新于2025-09-23 15:22:29
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An interprojection sensor fusion approach to estimate blocked projection signal in synchronized moving grid-based CBCT system
摘要： Purpose: A preobject grid can reduce and correct scatter in cone beam computed tomography (CBCT). However, half of the signal in each projection is blocked by the grid. A synchronized moving grid (SMOG) has been proposed to acquire two complimentary projections at each gantry position and merge them into one complete projection. That approach, however, suffers from increased scanning time and the technical difficulty of accurately merging the two projections per gantry angle. Herein, the authors present a new SMOG approach which acquires a single projection per gantry angle, with complimentary grid patterns for any two adjacent projections, and use an interprojection sensor fusion (IPSF) technique to estimate the blocked signal in each projection. The method may have the additional benefit of reduced imaging dose due to the grid blocking half of the incident radiation. Methods: The IPSF considers multiple paired observations from two adjacent gantry angles as approximations of the blocked signal and uses a weighted least square regression of these observations to finally determine the blocked signal. The method was first tested with a simulated SMOG on a head phantom. The signal to noise ratio (SNR), which represents the difference of the recovered CBCT image to the original image without the SMOG, was used to evaluate the ability of the IPSF in recovering the missing signal. The IPSF approach was then tested using a Catphan phantom on a prototype SMOG assembly installed in a bench top CBCT system. Results: In the simulated SMOG experiment, the SNRs were increased from 15.1 and 12.7 dB to 35.6 and 28.9 dB comparing with a conventional interpolation method (inpainting method) for a projection and the reconstructed 3D image, respectively, suggesting that IPSF successfully recovered most of blocked signal. In the prototype SMOG experiment, the authors have successfully reconstructed a CBCT image using the IPSF-SMOG approach. The detailed geometric features in the Catphan phantom were mostly recovered according to visual evaluation. The scatter related artifacts, such as cupping artifacts, were almost completely removed. Conclusions: The IPSF-SMOG is promising in reducing scatter artifacts and improving image quality while reducing radiation dose.
关键词： moving grids,scatter correction,interpolation,sensor fusion,geometric model,SMOG,dose reduction,CBCT
更新于2025-09-23 15:22:29
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LSBs-based quantum color images watermarking algorithm in edge region
摘要： Based on the NEQR representation for quantum color and binary images, an enhanced quantum watermarking scheme is investigated through Gray code transform and least significant bit (LSB) steganography, which embeds a quantum binary image (i.e., watermark image) into the edge region of a quantum color image (i.e., carrier image) LSB and second LSB. The size of the carrier and watermark images are assumed to be 2n × 2n and 2n?1 × 2n?1, respectively. At first, the watermark image is resized into an appropriate size image with 4-qubit grayscale based on the nearest neighbor interpolation method, which is of the same size with the preselected edge region in carrier image. To enhance the security of the watermark image, the binary code of 4-qubit grayscale of watermark image is transformed into the corresponding Gray code, and one 3-Controlled-NOT gate is utilized to generate a quantum binary image |K 1(cid:2). To further scatter the watermark image qubits that are embedded into the LSB and second LSB of carrier image, the quantum image |K 1(cid:2) is employed to choose any two channels from the color image among the three channels of R, G and B (i.e., R, G or R, B channels would be chosen as the embedding channels). Furthermore, a quantum binary image |K 2(cid:2) is generated through XOR operation decided by the quantum image |K 1(cid:2), which is used to determine the embedding order of watermark image qubits. The extraction process is the inverse operation of embedding, which also needs the two quantum binary key images |K 1(cid:2) and |K 2(cid:2). Finally, the experiment results are simulated under the classical computer software MATLAB 2016(b), which illustrates that our investigated LSBs-based quantum watermarking has a better visual effect than some related works in terms of PSNR value.
关键词： Nearest neighbor interpolation,Gray code transform,Quantum watermarking,Least significant bit
更新于2025-09-23 15:21:21
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Multi-fidelity EM simulations and constrained surrogate modelling for low-cost multi-objective design optimisation of antennas
摘要： In this study, a technique for low-cost multi-objective design optimisation of antenna structures has been proposed. The proposed approach is an enhancement of a recently reported surrogate-assisted technique exploiting variable-fidelity electromagnetic (EM) simulations and auxiliary kriging interpolation surrogate, the latter utilised to produce the initial approximation of the Pareto set. A bottleneck of the procedure for higher-dimensional design spaces is a large number of training data samples necessary to construct the surrogate. Here, the authors propose a procedure that allows us to confine the model domain to the subset spanned by the reference points, including the extreme Pareto-optimal designs obtained by optimising the individual objectives as well as an additional design that determines the Pareto front curvature. Setting up the surrogate in the constrained domain leads to a dramatic reduction of the required number of data samples, which results in lowering the overall cost of the optimisation process. Furthermore, the model domain confinement is generic, i.e. applicable for any number of design goals considered. The proposed technique is demonstrated using an ultra-wideband monopole antenna optimised with respect to three objectives. Significant reduction of the design cost is obtained as compared to the reference surrogate-assisted algorithm.
关键词： Pareto set,antenna structures,variable-fidelity EM simulations,kriging interpolation surrogate,multi-objective design optimisation,ultra-wideband monopole antenna
更新于2025-09-23 15:21:21
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PATTERN SYNTHESIS FOR LARGE PLANAR ANTENNA ARRAYS USING A MODIFIED ALTERNATING PROJECTION METHOD
摘要： A pattern synthesis approach based on a modi?ed alternating projection method for large planar arrays is presented in this paper. In the alternating projection method, pattern synthesis problem is considered as ?nding the intersection between two sets: the speci?cation set and the feasible set. The former contains all the patterns that want to be obtained, while the latter contains all the patterns that can be realized. An element belongs to both sets is a solution to the problem. In this paper, a modi?ed projection operator which varies with the iteration number is introduced because the conventional alternating projection method is known to su?er from low convergence rate and/or trapping on local optimum depending on the starting point. When the planar array has a nonuniform element layout, the unequally spaced elements are interpolated into virtual uniform elements with an interpolation of the least square sense. Then the synthesis problem is converted to the problem of a uniform array. Finally, several examples are presented to validate the advantages of the proposed method. Results show that the modi?ed method is fast and obtains better results than the conventional one.
关键词： modi?ed alternating projection method,interpolation,planar antenna arrays,nonuniform element layout,pattern synthesis
更新于2025-09-23 15:21:21
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Numerical Modeling of Acousto-Plasmonic Coupling in Metallic Nanoparticles
摘要： We describe a computational approach to study the acousto-plasmonic coupling in metallic nanoparticles. We use the high level multiphysics finite element software FreeFEM developed at Laboratoire Jacques-Louis Lions of Pierre and Marie Curie University (Paris). Our numerical method determines one after the other the acoustic modes of the nanoparticles and the modulation of the electromagnetic properties. The transfer of the deformed geometries between acoustic and electromagnetic simulations is realized by an update of the nodal coordinates situated at the boundary between the nanoparticle and its host medium, and using a mesh deformation algorithm based on radial basis function interpolation. Thus we theoretically investigate different coupling mechanisms between confined vibrations and surface plasmons: shape effect, electron density effect due to changes of the nanoparticle volume and inter-band transitions effect which is evaluated by the deformation potential mechanism.
关键词： acousto-plasmonic coupling,radial basis function interpolation,FreeFEM,finite element method,metallic nanoparticles
更新于2025-09-23 15:21:01