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提出了一种基于图像全局和局部颜色特征的图像检索方法.首先在符合视觉感知特性的Lab颜色空间中提取全局颜色特征;再对图像进行图像子块划分,同时利用具有人眼视觉特性的高斯加权系数对其进行加权,然后利用二值化得到的颜色位图作为局部颜色特征,并进一步加入了方向性的考虑,对图像子块进行垂直和水平投影,最后合理地融合了全局和局部颜色特征的相似性进行图像检索.对Corel图像数据库的实验结果表明,此算法具有良好的检索效率. 相似文献
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基于正则化方向失真的压缩图像质量评价 总被引:1,自引:0,他引:1
图像质量评价是图像和视频处理系统中的基本算法。该文在分析人眼视觉系统对图像感知特点的基础上,结合二维图像的几何本征特征研究,提出了一种新型的基于图像正则化方向失真的完全参考质量评价算法。该方法计算简单,物理意义明确。仿真试验结果表明,该方法符合人眼视觉系统特性,所得到的图像质量客观评价结果与主观评价结果之间具有更好的一致性。 相似文献
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基于人眼视觉特性的彩色图像质量评价 总被引:4,自引:0,他引:4
图像处理系统的性能优劣的评判往往需要一个合理迅速的图像质量评价算法作为支撑.传统的图像质量评价算法由于没有充分考虑人眼的视觉特性,使得质量评价结果与实际图像的人眼感知质量不符.根据人眼对图像边缘信息非常敏感这一人眼视觉特性,提出一种综合图像边缘和背录相似度的算法(EBS)来评价彩色图像质量,即通过比较失真彩色图像与原始参考图像的边缘以及除边缘之外的背景相似程度最终确定失真图像的质量.应用于由779幅包含五种类型失真的图像质量评价库的实验结果表明,该算法的评价结果相比PSNR,MSSIM,IFC以及基于像素域的VIF等算法与图像的主观评价结果(由DMOS值表示--将背景不同的一组观察者对失真图像的评分进行统计平均后所得到的评价结果)更一致,也即该算法的评价结果更接近图像的实际视觉感知质量. 相似文献
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感知哈希(Perceptual Hashing)是多媒体数据集到摘要集的单向映射,为多媒体数字内容的标识、检索、认证等应用提供了安全可靠的技术支撑.本文提出一种融合视觉感知及时空域特征的视频感知哈希算法.算法首先对视频序列每一帧进行随机可重叠分块,并计算每个分块以像素为单位的亮度均值,在某一步长下,以同一帧的分块亮度差作为视频帧空域特征,以不同视频帧相同位置的分块亮度差作为时域特征,通过哈希量化得到时空域感知哈希,通过时空域感知哈希融合,最后得到简洁的视频唯一标识——摘要哈希.实验结果表明,该算法表现出较好的鲁棒性与区分性,通过相似度拟合图算法分析,可以实现视频篡改的准确检测及定位. 相似文献
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为了使图像压缩后的效果更加符合人眼感知特性,提出了一种结合人眼对比度敏感视觉特性的图像压缩算法。算法首先结合视觉特性和图像变换域频谱系数特征,提出一种图像的角频率的计算方法,并依据计算的角频率提出一种人眼觉察图像最小误差阈值的计算方法;然后以此阈值作为量化步长,提出一种图像变换域频谱系数的量化方法;最后采用霍夫曼编码算法进行编解码,实现图像的压缩。并对三幅彩色图像进行了仿真实验,结果表明:与JPEG技术相比,三幅彩色图和各分量图的平均压缩比、PSNR和SSIM依次提高了10.4807%、6.9879%和2.6494%。表明提出的结合人眼视觉特性的图像压缩算法是一种较好的、有实用价值的压缩算法。 相似文献
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SONG Jian-xin 《中国邮电高校学报(英文版)》2003,10(4)
1 IntroductionStreamingvideoisoneofthemostexcitingap plicationsontheInternet[1~3] .However,severalproblemsneedtobesolvedinordertodeliverastreamingvideoontheInternet[4] .Theuniformityofperceptualimagequality[5~ 6] isoneofthechal lengesinthedesignofvideocodecforstreamingvideo.Owingtotheintrinsicnon stationarityofavideosource ,basedontherate distortiontheory ,thebitrateofcompressedvideovariesintimeiftheimagequalityiskeptuniform .Ontheotherhand ,becausetheInternetisbasedonthemechanismofstatis… 相似文献
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Amit Phadikar 《Journal of Visual Communication and Image Representation》2012,23(3):454-466
This paper proposes a tamper detection and correction technique using semi-fragile data hiding that aims to achieve high perceptual quality of images at the user-end even after malicious modifications. A binary signature and an image digest are embedded by modulating integer wavelet coefficients using dither modulation based quantization index modulation. Half-toning technique is used to obtain image digest from the low-resolution version of the host image itself. Decoder extracts the binary signature from the watermarked image for tamper detection, while the extracted image digest is used to correct the tamper region. Unlike previously proposed techniques, this novel approach distinguishes malicious changes from various common image processing operations more efficiently and also correct tapered regions effectively. Experimental results show that the proposed technique provides a superior performance in terms of probability of miss and false alarm as well as in tamper correction, compared to several existing semi-fragile watermarking techniques. 相似文献
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Recent years have witnessed that the multimodal medical image fusion (MMIF) plays critical roles in clinical diagnostics and treatment. Many MMIF algorithms have been proposed to improve the MMIF images quality. The quality of multimodal medical fused images will significantly affect the results of the clinical diagnosis. However, little work has been designed to evaluate the effectiveness of MMIF algorithms and the quality of MMIF images. To this end, this paper presents a perceptual quality assessment method for MMIF. A MMIF image database (MMIFID) is first built to employ the classical MMIF algorithms, and the subjective experiment is conducted to assess the quality of each fused image. Then, a no-reference objective method is proposed for the perceptual quality evaluation of MMIF images,which uses Pulse Coupled Neural Network (PCNN) in Non-subsampled Contourlet Transform (NSCT). A fused image is decomposed by NSCT into low frequency sub-band (LFS) and high frequency sub-band (HFS). It is used to motivate the PCNN processing, and large firing times are employed to measure LFS and HFS. Finally, two components evaluation results are combined to obtain the overall objective quality score. Experimental results based on the MMIFID indicate that our presented method outperforms the existing image fusion quality evaluation metrics, and it provides a satisfactory correlation with subjective scores, which shows effectiveness in the quality assessment of medical fused images. 相似文献
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Visual perception of computer-generated stereoscopic pictures: Toward the impact of image resolution
In comparison with the generation of monoscopic images, the time cost of rendering stereoscopic images is doubled. When generating stereoscopic images by computer algorithms, it is desirable to save the computational expense by decreasing the image resolution, without degrading the visual perceptual quality of the images. In this work, to evaluate the perceptual visual quality of computer-generated stereoscopic images (CGSIs), a data set consisting of stereoscopic images created with different horizontal and vertical resolutions was constructed. First, a series of subjective experiments for the analysis of various perceptual situations was conducted. The experimental results show that when the original image resolution was reduced by half, the image difference was not perceptible. In addition, based on full-reference (FR) and no-reference (NR) image quality measurement (IQM), a combined FR-and-NR CGSIQA model was established to predict perceptual quality. We perform weighting calculations for different combinations of FR and NR. The experimental results show that the proposed model significantly outperforms all the classical models. 相似文献
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视觉评价夜视彩色融合图像质量的实验研究 总被引:11,自引:3,他引:8
提出夜视彩色融合图像质量评价的三个基本指标是“目标探测性”、“细节”和“色彩”,并且通过视觉评价实验,研究了“感知质量”与这三个指标的相关性.对十个场景的微光与红外图像采用四种融合算法产生的40幅假彩色图像进行评价实验,实验结果得出:融合图像都有好目标探测性,感知质量与目标探测性的相关性很小;感知质量与细节的相关系数是0.89,感知质量与色彩的相关系数是0.75.说明在满足目标探测性要求条件下,细节是视觉感知融合图像质量的最主要评价指标,而且色彩成为夜视彩色图像质量的一个重要指标. 相似文献
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基于小波重构和灰度分段的红外图像放大增强 总被引:3,自引:0,他引:3
传统的内插算法在放大红外图像时都存在着一定的缺陷,提出了一种基于小波重构和灰度分段变换的图像放大新算法.该算法先对原始图像进行小波变换获得高频系数,运用牛顿插值算法放大高频系数作为放大图像的高频成份,再将原始图像作为低频成份,进行小波重构,可得放大图像.为了增强放大图像,将图像按双灰度闽值分割成对应目标的灰度值高段、对应背景的灰度值低段和对应过渡区域的灰度值中段等3个部分,对各部分采用不同的线性变换,获得最佳的视觉效果.实验证明该方法在图像细节方面具有很好的放大效果. 相似文献
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本文介绍了邻域图像处理机原理,提出了邻域图像处理中新型的收缩型和级联型邻域功能流水线结构.这两种邻域功能流水线的流水线作业是以独立的图像处理算法为基础进行的,可以实时(甚至超实时)地完成多个独立的图像处理算法,高度体现了并行处理机数据并行、处理并行的原则,体现了多个算法的有机集成,因此特别适合于实际问题对综合算法的需求.这种邻域功能流水线结构不仅大大提高了图像处理的速度,而且增强了系统的灵活性.本文论述了收缩型和级联型邻域功能流水线的结构,给出了多个图像处理功能的组合. 相似文献