共查询到17条相似文献,搜索用时 156 毫秒
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针对复杂背景中伪装目标偏振检测的问题,以中国颜色体系为基础,基于CIE1976L*a*b*颜色空间建立了LMS和l两种颜色空间的256级亮度分量数据表,通过外场偏振检测实验,找到了目标与背景偏振度对比较高时的偏振片最佳参考方向,并研究了这两种空间在此方向上表征偏振信息的优劣和反映偏振检测能力强弱的问题。实验结果表明,以偏振片最大透光方向垂直于入射面为参考方向,在亮照度下,L空间的偏振图相比其灰度图信息量降低甚少,表征目标偏振信息量能力较强;在暗照度下,l空间的偏振图相比其灰度图不仅目标与背景的对比度明显提高,而且对阴影目标检测能力较强,实验结果与人眼观察结果一致。 相似文献
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基于图像分析的光学伪装效果评价方法研究 总被引:2,自引:0,他引:2
传统的伪装评价方法受到很多条件的限制,需要客观定量反映伪装效果的评价方法.基于量化颜色直方图对伪装方案与实际背景的颜色相似度进行定量评价,利用灰度共生矩阵和小波变换方法计算伪装与背景的纹理相似度.该评价方法不仅能表示伪装与背景的颜色和纹理相似程度,还能反映不同观察距离上伪装与背景的纹理相似度. 相似文献
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提取背景代表色是进行迷彩伪装图案设计的基础,对军用车辆实施迷彩伪装,需使代表色满足国军标规定的军用车辆伪装涂料漆膜标准色要求。文中提出两种基于K-mean聚类算法的车辆伪装涂料漆膜标准色选取算法。利用CEI1976 L*a*b*颜色模型描述图像颜色特征。第一种算法是随机选取标准色作为初始聚类中心,每经过一次K-mean聚类迭代都将聚类中心更新为标准色;第二种算法是将选取的背景颜色空间值作为初始聚类中心进行迭代。提出了优化的标准色选取决策,解决了聚类结果易出现标准色重复的问题。结合提取标准色数量不同,共提出4种标准色提取方案,用均方根误差函数作为评价函数进行融合效果比较。仿真结果表明,两种算法均能较好地满足迷彩伪装设计要求,从最小均方根误差和收敛速度上比较,第一种算法优于第二种,其提取三种标准色的方案优于五种标准色方案。 相似文献
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针对RGB和l空间转换过程复杂,运算速度慢,不便于用灰度融合图像直接代替亮度分量的问题,提出了一种基于YC C空间的伪彩色融合方法。该方法首先对源图像进行基于特征差异的颜色映射,所得RGB图像通过YC C变换提取亮度分量Y;然后采用新的融合规则对红偏振与光强图像进行了支持度融合,其中低频和高频分别采用目标背景分割和区域方差最大的融合规则;最后用融合结果代替亮度分量,再与C,C分量进行YC C逆变换,得到伪彩色图像。实验结果表明,与文献[8]方法比较局部方差提高21.5%、对比度提高1.15%、清晰度提高6.05%、运算速度提高30.5%,证明了本文算法的可行性和有效性。 相似文献
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为了提高灰度图像中人眼视觉的情景感知和目标的识别率,提出了多参数亮度值重映射的颜色传递方法,将灰度图像赋予色彩。该方法首先将灰度目标图像和彩色参考图像由RGB颜色空间转换到亮度与色彩分离的YCbCr颜色空间。然后,引入由彩色参考图像和灰度目标图像的列数和亮度共同决定的参数,对彩色参考图像的亮度值进行运算,使彩色参考图像与灰度目标图像具有相同的亮度值动态范围。最后,根据目标像素和它周围的像素存在相关性,进行灰度目标图像与彩色参考图像的像素匹配后,将得到的结果再逆变至可以表示出各种色彩的RGB颜色空间。该颜色传递方法降低了色彩误传现象,提高了颜色传递的准确度并缩短了程序的运行时间。 相似文献
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Kuo-Cheng Liu 《AEUE-International Journal of Electronics and Communications》2010,64(2):112-124
In this paper, a wavelet-based watermarking scheme for color images is proposed. The watermarking scheme is based on the design of a color visual model that is the modification of a perceptual model used in the image coding of gray scale images. The model is to estimate the noise detection threshold of each wavelet coefficient in luminance and chrominance components of color images in order to satisfy transparency and robustness required by the color image watermarking technique. The noise detection thresholds of coefficients in each color component are derived in a locally adaptive fashion based on the wavelet decomposition, by which perceptually significant coefficients are selected and a perceptually lossless quantization matrix is constructed for embedding watermarks. Performance in terms of robustness and transparency is obtained by embedding the maximum strength watermark while maintaining the perceptually lossless quality of the watermarked color image. Simulation results show that the proposed scheme is more robust than the existing scheme while retaining the watermark transparency. 相似文献
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A new method of contrast enhancement based on steerable pyramid transform is presented in this work. The use of steerable
filters is motivated by the fact that the images are to be observed by human and therefore it would be better to incorporate
some knowledge on the Human Visual System in the design of the image processing tool. Here, the frequency and directional
selectivity of the HVS is modeled by the steerable filters. The contrast is amplified using a selective nonlinear function
which simulates the nonlinearity response of the HVS to the luminance stimuli. So the basic idea is to enhance the luminance
signal irrespective of the two chrominance components using a multidirectional and multiscale decorrelation color transform.
Initially the rgb (red, green and blue) color image is converted to lab (luminance and chrominance) color image. Only the luminance component
is transformed by the steerable pyramid transform, so that the luminance component is independently decomposed into different
scale and orientation sub-bands. The contrast in each sub-band is enhanced using a nonlinear mapping function. Finally the
rgb color image is obtained from the enhanced luminance component along with the original chrominance components. The performance
of the proposed method is objectively evaluated using spectrum energy analysis and a visibility map based on a perceptual
filtering model. The obtained results confirm the efficiency of the method in enhancing subtle details without affecting color
balance and without the usual noise amplification and edge ringing effect. 相似文献
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We develop and evaluate motion compensation schemes for predictive coding of the component color television signal. Algorithms are discussed for estimation of motion of each color component (luminance and chrominance) separately as well as in combination. Techniques for switching of the predictors for individual components are proposed and simulated. Simulations show that it is sufficient to estimate parameters of motion based only on the luminance and use them for motion-based prediction and switching the predictors for both the luminance and chrominance. Thus, only one motion estimator and prediction switch is needed for the three components of the color signal. Compression capability of motion compensation is scene dependent, in some video conference type of scenes, bit rate is reduced by as much as 60 percent compared to conditional replenishment coding. 相似文献
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图象质量的主观评价按评价方法的单项要素有;色纯,会聚,高度和色度分量间的重合,灰度绝调,几何失真和图象重显度,灰度重现,彩色满意度,图象干扰等,此外还有“清晰度”和总的图象质量”,在其它要素较好的情况下,这两个要素决定了彩电的技术水平,为提高图象质量采用了各种动态调整技术。 相似文献