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本文提出了一种基于高速相机和时域空域解耦人眼视觉系统模型的新型运动图像清晰度客观测试方法,具有采用静态、动态一致的显示线作为评价参数,更完善的人眼视觉系统算法,基于调制度的客观测试能力等优点。本文采用高速相机、瞬态光度计、视频发生器实现了测试系统的原理性试验装置,并研制了软件验证算法。核心算法与测试序列已得到国家发明专利授权并得到系统试验验证。 相似文献
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现有的时域恰可察觉失真(just noticeable distortion,JND)模型对时域特征参量的作用刻画尚不够充分,导致空时域JND模型精度不够理想。针对此问题,提出能准确刻画视频时域特性的特征参量以及异质特征参量同质化融合方法,并基于此改进时域JND模型。关注前景/背景运动、时域持续时间、时域预测残差波动强度、帧间预测残差等特征参量,用来刻画视频内容的时域特征;基于人眼视觉系统(human visual system,HVS)特性探索感知概率密度函数,将异质特征参量统一映射到自信息和信息熵尺度上,实现同质化融合度量;从能量分配的角度探究视觉注意与掩蔽的耦合方法,并据此构建时域JND权重模型。在空域JND阈值的基础上,融合时域权重以得到更加准确的空时域JND模型。为了评估空时域JND模型的性能,进行了主观质量评估实验,与现有的JND模型相比,在感知质量接近的情况下,提出的空时域JND模型能够容忍更多失真,具有更强的掩藏噪声的能力。 相似文献
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针对现有图像质量评价方法的缺陷,通过深度学习理论建模人眼视觉系统(human vision system,HVS)特性,提出了一种基于视觉特征深度感知与学习融合(deeply perception and learning for pooling,DPLP)的评价方法.首先为了增加图像视觉特征的稳定性,根据人眼感光的空域结构特征和频域多通道特性,对图像依次进行二维Log-Gabor小波变换、梯度变换和频谱残余的深度视觉信息处理,然后分别提取各层视觉信息进行质量评价.其次为了克服HVS融合的不确定性,对质量评价信息采取了深度池化策略,第一层为评价视图的空域融合,采取了符合人眼感光特性的高斯加权策略;第二层为多通道评价的频域融合,采取了具有HVS推理能力的BP神经网络的学习-预测策略;第三层为各级视觉特征的评价融合,采取了具有自适应特性的回归函数策略.最后,基于现实中的各种失真类型图像进行了实验,结果表明所提方法具有较高的主客观评价一致性水平和更好的稳定性. 相似文献
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图像质量客观评判标准广泛应用于图像处理中,基于人眼视觉系统的客观评判方法一直是图像处理领域的研究热点.最近,Zhou Wang等人提出了基于结构信息的评判方法—结构相似度(SSIM),它的理论基础是人眼视觉系统能高度自适应地提取场景中的结构信息.SSIM方法简单、评判性能优于PSNR(或MSE).但随着研究的深入,我们发现SSIM算法存在着一些问题,特别是不能很好地评判模糊失真类的图像.本文提出两种基于梯度信息的图像质量评判方法—基于梯度的结构相似度(GSSIM)和基于边缘的结构相似度(ESSIM).实验结果表明,GSSIM能更好地符合人眼视觉系统特性,而ESSIM对于模糊图像则取得了最好的评判效果. 相似文献
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自适应调制编码(AMC)是高速下行分组接入(HSDPA)的关键技术之一,它可以根据信道质量情况的改变调整调制与编码方式,从而合理地利用和分配系统资源.文中概述了AMC技术原理、特点、结构和流程,对基于TD-SCDMA的AMC 技术性能进行仿真和分析.通过仿真结果,分析了在不同情况下该编码的主要技术特点,并做出了相关的结论. 相似文献
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A new modulation scheme for IR-UWB communication systems 总被引:1,自引:0,他引:1
Since the poor performance of orthogonal binary Pulse Position Modulation (PPM) compared with binary Pulse Amplitude Modulation (PAM), this paper presents a new modulation scheme named Pulse Width Modulation (PWM) for Impulse Radio Ultra-WideBand (IR-UWB) communication systems. This modulation scheme uses pulses with equal amplitude and different widths to carry different information. The receiver employs differences between similarity coefficients among these pulses to distinguish different information. Bo... 相似文献
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《Digital Communications & Networks》2019,5(3):183-188
Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is to extend the spatial constellation of the conventional Spatial Modulation (SM) in both the in-phase and quadrature components of the data symbol. In this paper, because QSM-based on Interleaving Division Multiplexing (IDM) has not been introduced in the literature as a multiple antenna system, we introduced a novel scheme, called QSM system based on Interleaving Division Multiplexing (QSM-IDM). The antenna sets are also applied to a spreader, before being used to assign an antenna number for information transmission. Analysis and simulations for a flat fading channel show that the proposed QSM-IDM method significantly outperforms the original QSM system with the same data rate, while maintaining a relatively acceptable complexity. The obtained simulation results show that the conducted analysis yields significant improvements for the accuracy of the proposed scheme, with satisfactory complexity. 相似文献
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信号在调制方式不同的系统之间传输时,需要对信号调制格式进行转换,而调制格式转换通常在电信号上进行,要将光信号恢复成电信号。在电信号上进行调制格式转换后,再经电光调制器变换成光信号发射。频繁的光电或电光转换通常会增加系统成本,针对该问题,提出了利用相干叠加在光域上实现二进制相移键控(BPSK)到正交相移键控(QPSK)以及QPSK到正交幅度调制(16QAM)的调制格式转换的方法。实验通过Optisystem软件对转换模型进行仿真,采用10 Gpbs伪随机信号作为测试信源,通过星座图观测出信号成功转换为QPSK和16QAM;并在不同光信噪比、光源线宽和信号功率下对转换模型与直接QPSK、16QAM传输模型进行误码分析对比,在相同条件下转换模型和直接传输的误码率高度保持一致,表明这种调制格式转换方法具有较高的稳定性和准确性,能够适用于不同系统间的信号传输。 相似文献
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Wang Jiaqing Yu Xiaoyan Wu Lenan 《电子科学学刊(英文版)》2006,23(2):189-192
In Digital Radio Mondiale (DRM) system, achieving good audio quality becomes a challenge due to its limited band-width of 9 or 10kHz and the very bad lading channels. Therefore, DRM needs highly efficient channel coding schemes. This paper, proposes the schemes which use the Low-Density Parity-Check (LDPC) coded Bit-Interleaved Coded Modulation (BICM) schemes for the implementation of DRM systems. Simulation results show that the proposed system is more efficient than the Rate Compatible Punctured Convolutional (RCPC) coded DRM system on various broadcast channels, and may be recommended as a coding technology for Digital Amplitude Modulation Broadcasting (DAMB) systems of China. 相似文献
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In the field of augmented reality technologies, commercial optical see‐through‐type wearable displays have difficulty providing immersive visual experiences, because users perceive different depths between virtual views on display surfaces and see‐through views to the real world. Many cases of augmented reality applications have adopted eyeglasses‐type displays (EGDs) for visualizing simple 2D information, or video see‐through‐type displays for minimizing virtual‐ and real‐scene mismatch errors. In this paper, we introduce an innovative optical see‐through‐type wearable display hardware, called an EGD. In contrast to common head‐mounted displays, which are intended for a wide field of view, our EGD provides more comfortable visual feedback at close range. Users of an EGD device can accurately manipulate close‐range virtual objects and expand their view to distant real environments. To verify the feasibility of the EGD technology, subject‐based experiments and analysis are performed. The analysis results and EGD‐related application examples show that EGD is useful for visually expanding immersive 3D augmented environments consisting of multiple displays. 相似文献
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Hye Sun Park Min Woo Park Kwang Hee Won Kyong‐Ho Kim Soon Ki Jung 《ETRI Journal》2013,35(6):1038-1047
Augmented reality (AR) is currently being applied actively to commercial products, and various types of intelligent AR systems combining both the Global Positioning System and computer‐vision technologies are being developed and commercialized. This paper suggests an in‐vehicle head‐up display (HUD) system that is combined with AR technology. The proposed system recognizes driving‐safety information and offers it to the driver. Unlike existing HUD systems, the system displays information registered to the driver's view and is developed for the robust recognition of obstacles under bad weather conditions. The system is composed of four modules: a ground obstacle detection module, an object decision module, an object recognition module, and a display module. The recognition ratio of the driving‐safety information obtained by the proposed AR‐HUD system is about 73%, and the system has a recognition speed of about 15 fps for both vehicles and pedestrians. 相似文献
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最近,一种不需要观看者配戴任何光学眼镜就能欣赏到三维立体图象的新技术引起了人们的关注,本文介绍了这种三维显示技术的基本工作原理,特点,应用领域及发展方向。 相似文献
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自动立体显示技术使用户可以在显示屏幕前的不同位置通过裸眼观看到清晰的立体图像.基于自动立体显示技术领域的专利文献,给出了对该领域专利总体变化情况的统计分析结果,通过一些典型的专利文献介绍了专利中的技术发展情况,并分析了主要专利申请人所申请专利的技术特点,由此对今后的专利发展趋势进行预测.通过专利分析,希望对业内人士有所帮助. 相似文献