共查询到18条相似文献,搜索用时 187 毫秒
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本文分别选择无压缩、LZW压缩、ZIP压缩、JPEG压缩四种不同压缩格式对多种阶调的TIFF图像文件(GATF)进行压缩评价,比较压缩前后图像的峰值信噪比、均方误差、色域图以及图像清晰度的差异,以评价压缩格式对印刷数字原稿图像质量的影响。实验结果表明,ZIP和LZW压缩格式的图像质量与无压缩原稿的图像质量最为接近,JPEG有损压缩(最高质量)对数字原稿质量的影响在可接受范围之内。 相似文献
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闭路电视监控作为一项先进的高科技防范手段,特别是由于系统本身具有直观、实时、记录、回放等特点,在许多领域得到越来越广泛的应用。着重介绍了H.264视频压缩技术和视频网络传输技术的同时,对前端视频处理、传输系统设计、远程联网集中平台管理以及视频存储、转发与显示等全方面的纯数字高清网络视频监控系统进行了研究设计。 相似文献
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文章以新一代网络技术、图像视频压缩技术、图像数字化传输技术为核心,结合大屯公司现状,设计网络化视频监控系统,解决了模拟系统的诸多弊端,为大屯公司的安全生产提供了更加先进的监控方案。 相似文献
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为了减少背景噪声干扰,准确地从复杂视频中提取显著目标,提出一种具有时空一致性的视频显著区域检测算法。将视频帧划分为超像素,以超像素为基本单元提取光流特征,在时空一致性原则指导下动态融合颜色、边界信息和光流特征,获取视频显著图。在此基础上,借助视频帧的细节和区域特征对视频显著图进行细化增强。实验结果表明,算法的准确率[CD*2]召回率曲线在复杂图像数据库中高于传统经典算法,具有足够高的鲁棒性,能够减少相机运动和背景运动以及突变情况对跟踪检测的影响。所提方法能够在各种运动模式下和外观复杂场景中较为完整地提取显著目标,可作为预处理技术,改善目标跟踪、行为检测、视频压缩等的性能。 相似文献
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利用完全信息动态博弈理论,对两发电商竞价上网即双寡头垄断的情形进行分析。算例表明,在发电成本相同的情况下先降低报价者具有"先动优势",而在发电成本不同的情况下,成本低者则始终具有竞争优势;同时,为保护购电商的利益,对最高报价进行合理限制十分必要。 相似文献
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作为操作风险计量本身就存在很大的不确定性,目前对于高频低冲击事件风险目前研究相对不足,针对其数据量大、极端值低的特点,采用风险价值计量可以预测最大损失的可能,通过对不同类型操作风险发生频率和损失概率分别进行预测,最后得到总的风险损失,为准备金的提取打下良好基础. 相似文献
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本文介绍了一种基于图像修复方法的图像压缩算法。首先对能够被精确覆盖的图像区域进行定位;然后将这些区域的信息消除以减少数据量;除了用于恢复被消除区域必要细节的数据外,对其余的数据进行编码以产生输出数据。在解码器中,使用从编码器中提取的信息可以重新获得被消除的图像区域。该修复技术利用偏微分方程(PDE)进行图像信息收集,其目的是达到图像压缩标准中的较高质量。本文还针对各种图像开展该算法的研究。采用这种算法,在图像质量可接受的条件下,压缩比可高达1:40。实验结果表明,与JPEG压缩方法相比,该算法在高压缩比下图像质量明显提高。 相似文献
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This paper measures the efficiency and revenue properties of the two most popular formats for divisible goods auctions: the uniform‐price and discriminatory auction. We analyze bids into the Korean Treasury auctions which have used both formats. We find that the discriminatory auction yields statistically higher revenue. Unlike previous work that uses data from only one format, we are able to compare the efficiency properties of the two formats. We find that the discriminatory auction better allocates treasury bills to the highest value financial institutions. However, the differences in revenue and efficiency are not large because the auctions are very competitive. 相似文献
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We present field evidence concerning experienced bidders that supports the linkage principle—specifically, the prediction that in affiliated‐values auction environments the expected revenues generated at open‐outcry, ascending‐bid auctions are higher than those under auction formats that reveal less information to participants. Using field data from a large seller of automobiles who experimented with different selling formats, we have found that average revenues were significantly higher under an English auction than under a dynamic Internet auction format that revealed less information to bidders. 相似文献
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Analyzing a panel dataset tracking format changes and ownership consolidation in local radio markets, we find that format
changes frequently have enabled stations to improve their performance, The success of reformatting varies widely across format,
and the likelihood that changing to another format will boost station performance declines as that format space becomes more
crowded, Successful reformatting is not limited to large radio groups, In fact, weak evidence that radio groups garner economies
of scope from owning multiple stations in the same format is the only indication we find that larger radio groups have been
able to choose formats strategically in order to obtain a boost in their listening shares. In the face of substantial and,
ongoing ownership consolidation in local radio markets, our results suggest that format changes by smaller station groups
may counter the potential exercise of market power by a radio group that acquires a substantial share of a particular audience
demographic through merger. 相似文献
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主要介绍活动图象压缩编码中最常用的几种运动补偿的算法——条件补充法和实现运动补偿技术的块匹配算法,梯度算法,傅立叶变化方法,其中也提出了用模糊数学处理方法,并指出,为了加快运动补偿向量的计算,搜索路径采取逐渐向外扩张的方式在运动较小的会议电视和可视电话中得到广泛应用;另一方法是计算象子块运动补偿时,只要所设定的(i,j)值的象块和原象块的相关系数达到一定的门限值就停止搜索,也会大大加快搜索的速度。 相似文献
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Natalia Fabra 《The Journal of industrial economics》2003,51(3):271-293
Within an infinitely repeated game, I compare the level and conduct of collusion under uniform and discriminatory auctions. For this purpose, I characterize the optimal collusive schemes and sets of sustainable profits under these auction formats. I show that uniform auctions facilitate collusion more than discriminatory auctions: the optimal penal code is equally severe under the two formats; but bidders' deviation incentives are weaker in uniform auctions given that the pay-off irrelevant bids can be used to relax the enforcement problem. This discussion is particularly relevant after the recent reforms in the electricity industry in England & Wales, and elsewhere. 相似文献