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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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数字视频编码技术是数字电视、视频会议/远程监控、视频点播、遍入千家万户的VCD/DVD,以及新一代移动通信等应用核心技术。H.264作为最新的视频编码标准,能够在尽可能低的码率(或存储容量)下获得尽可能好的图像质量。但随着市场对图像传输需求的增加,如何适应不同信道传输特性的问题也日益显现出来。本文针对H.264视频的编码与解码的性能与效率展开研究,采用两种不同格式的标准图像序列,选择多参考帧进行运动预测和运动补偿,分别在编码端和解码端进行仿真测试,比较各自的信噪比及压缩码率,从而为我们在有限资源的前提下,为解码端的抗误码性能与编码端参考帧的数量、编码效率以及计算复杂度之间做出合理的判断和权衡。 相似文献
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近年来,随着高清视频业务飞速发展,目前主流的视频压缩标准H.264已经显得有些力不从心,因此高清晰度、高压缩率的视频压缩标准就成为了当前研究的热点。本文主要针对未来的新一代视频编码标准HEVC(High Efficiency Video Coding),对其关键技术进行分析介绍。 相似文献
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熊馨 《郑州轻工业学院学报(自然科学版)》2000,15(3):63-65
通过对2种具有代表性的运动视频压缩标准H.261和MPEG-1在帧格式上的不同进行分析,总结出2类运动图像压缩标准H.X系列和MPEG系列的特点:H.261的编码延迟小,压缩比率不高;MPEG-1的压缩比率高但延迟较大。H.X适用于对实时性要求较高的场合,MPEG适用于存储读出系统。 相似文献
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综述了基于高效率视频编码HEVC(high efficiency video coding)标准的两种扩展,即MV-HEVC (high efficiency video coding based multiview)和3D-HEVC(high efficiency video coding based 3D video coding)的工作原理及其编码工具,分析了3D-HEVC 模型的特点、编码模块与方法,并将3D-HEVC与MV-HEVC进行了性能对比。总结发现,由于3D-HEVC 采用纹理视频加深度格式来合成虚拟视点,从而降低了大量的编码码率,可方便应用于3D电视、自由立体视点电视和3D数字电影等多种三维体验中。随着智能移动设备的发展,手持终端采用3D-HEVC支持多视点3D视频将会成为未来的研究趋势。 相似文献
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2.由于RIP后打样系统是通过接收照排RIP生成的1位TIFF图或者RIP中间文件而进行输出的,所以对制版软件及文件格式几乎没有要求.1位TIFF图包含了网点信息,因此文件数据量非常大,而一个作业一般要由4个1位TIFF图组成,所以在实际操作过程中速度非常慢;而RIP中间文件通常要经过压缩,因此数据量比1位TIFF格式要小一些,输出速度也要相对快一些. 相似文献
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目前很多数字相机可以提供JPEG、TIFF和RAW三种图像文件格式。大多数用户并不十分清楚这三种格式的区别,往往使用相机默认的文件数据量最小的JPEG格式,也有些人为了避免图像损失而使用非压缩的TIFF格式,很少有人去用RAW格式。如果了解了RAW格式的含义和使用方法,我们会发现使用这种格式可以很方便地对拍摄的图像进行调整,灵活地控制图像质量。专业的数字摄影师应该将摄影结果保存为RAW以便于后期的处理。要了解RAW文件所记录的内容,首先要从数字相机的图像数据记录原理说起。我们知道,RGB图像中每个像素的颜色由红、绿、蓝三… 相似文献
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本文针对网络视频监控设备的实际应用需求,设计了基于嵌入式Linux和ARM9的单画面视频监控系统。系统的硬件选用三星公司的S3C2440开发板,通过连接USB摄像头进行视频数据的采集。软件以嵌入式Linux的ubuntu操作系统为开发环境、选择H246算法对视频进行压缩,通过SOCKET传送回PC机上,客户端采用Qt技术实现界面并实时显示监控情况,同时以AVI格式存储以便播放历史录像。经测试,该系统能够实现实时视频监控及播放历史,且稳定性较好。 相似文献
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果蔬类农产品多源追溯系统设计与实现 总被引:2,自引:0,他引:2
目的 针对农产品质量安全问题, 以果蔬类农产品为研究对象, 通过分析农产品生产过程, 研究农事操作、生产环境、检测信息、生产视频的信息采集技术、数据交换技术、产品溯源技术。方法 采用C/S架构农产品企业的管理系统与B/S架构的农产品追溯系统相结合的模式, 设计开发农产品多源追溯系统。结果 实现了农产品环境数据自动采集、生产过程视频、生产农事记录的信息化管理, 并能够通过手机短信、触摸屏、手机二维码扫描、追溯网站等多种追溯方式对农产品生产信息追溯, 为提高农产品质量安全追溯水平提出了可行的解决方案。结论 该系统在山东滨州的追溯服务中心和农产品生产企业进行了应用示范。 相似文献
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畅应云 《北京印刷学院学报》2005,13(2):34-36
为尽可能占用较少的校园网带宽,向用户提供最佳的视频质量,更好地为远程教学服务,选用WindowsMedia流媒体技术,采用单播与多播服务方式,实现教学节目的点播与直播.通过采用DVCAM高质量数字视频存储格式以及广播级非线性编辑系统,既保证信号量损失最少,又实现了传统音视频技术与网络多媒体技术的完美融合.通过使用MMS协议传输ASF流,关闭Windows Media Service对ASF流的HTTP协议支持,在CBR编码中选用两次通过编码等一系列解决方案,保证了向用户提供一个可靠稳定的高质量MBR视频流. 相似文献
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The development of Eurocode 5, the future European timber design code which is based on the partial safety coefficient method, means a change of timber design code formats in a number of European countries. Because of the change in the code format from allowable values towards partial safety coefficients, characteristic values of strength and stiffness of materials and connections are needed. In order to establish characteristic values of the strength and stiffness of ring and shear-plate connections, existing test data have been evaluated. The results of the evaluation correspond well to a mechanical model assuming a shear block failure of the wood as the governing failure mode. 相似文献
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The development of Eurocode 5, the future European timber design code which is based on the partial safety coefficient method, means a change of timber design code formats in a number of european countries. Because of the change in the code format from allowable values towards partial safety coefficients, characteristic values of strength and stiffness of materials and connections are needed. In order to establish characteristic values of the strength and stiffness of tooth-plate connections, existing test data have been evaluated. The results of the evaluation correspond well to a calculation model assuming a load sharing between the connector and the bolt. 相似文献
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OPTIMIZATION OF WHEAT BLENDING TO PRODUCE BREADMAKING FLOUR 总被引:1,自引:0,他引:1
Linear programming was utilized to optimize the blending of wheat lots which have different quality characteristic and costs. Using best subsets regression three quality tests (particle size index, dough volume and falling number value) were selected in relation to loaf volume of bread to be produced. The chosen criteria were set up in a linear programming format as a model for the computerized solution. The model's applicability was assessed in a commercial mill. As a result of applying the model it was found possible to produce breadmaking flour with a reasonable quality and at a lower cost. 相似文献
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A.F. LACERDA M.H. LISBOA M.S. OLIVEIRA M.A.S. BARROZO 《Journal of food process engineering》2004,27(6):432-448
The purpose of the present work is to study the simultaneous heat and mass transfer between air and soybean seeds in a countercurrent moving bed dryer, based on the application of a two‐phase model to the drying process. The numerical solution of the model is obtained by using a computational code based on backwards differential formulae. The experimental data of air humidity and temperature and of seed moisture content and temperature at the dryer outlet are compared to the simulated values, showing a good agreement. This work also analyzes the effect of the main process variables (drying air temperature, air relative humidity, air velocity and solids flow rate) on the soybean seeds quality during drying. Empirical equations fitted to the experimental data are proposed for predicting the soybean seed quality (germination, vigor and fissures) as a function of the investigated variables. 相似文献
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Kevin J. Hanley Kevin CroninCatherine O’Sullivan Mark A. FenelonJames A. O’Mahony Edmond P. Byrne 《Journal of food engineering》2011,107(1):71-79
The objective of this paper is to investigate the relationship between the compositions of four typical infant formulae, the evolution of key quality characteristics during pneumatic conveying and the mechanical properties of individual agglomerates. Conveying experiments were conducted using a lab-scale rig. Four quality characteristics were measured before and after conveying: bulk density, volume mean diameter, wettability and percentage free fat. Relative breakages were calculated from particle size distributions. Uniaxial compression experiments were performed on individual agglomerates, giving forces and strains at failure and agglomerate stiffnesses. Coefficients of restitution of the agglomerates were obtained by video analyses of drop tests. The data indicate that bulk densities before conveying and the force and the strain of individual agglomerates at failure were related to the protein content. The force at failure and agglomerate stiffness were strongly correlated, and generally increased with increasing protein to fat ratio while the strain at failure decreased. 相似文献
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本文以糙米为原料,探究了低温等离子体对糙米的营养成分、蒸煮品质、感官品质、质构特性、糊化特性、微观结构、结晶度和近红外图谱的影响。结果表明,相比较于对照组糙米,低温等离子体处理后糙米的加热吸水率、体积膨胀率和固形物损失率显著增加到236.10%、268.25%和19.18 mg/g (P<0.05);直链淀粉、蛋白质、膳食纤维和非必需氨基酸的含量也有一定程度的增加。低温等离子体处理改善了糙米饭的糊化特性、质构特性和感官品质,有利于糙米饭品质的提升。通过对低温等离子体处理后糙米皮层微观结构的观察分析,糙米皮层遭到破坏,表面出现凹陷和裂缝;X射线衍射和近红外数据分析得出,糙米经低温等离子体处理后亲水基团增加,结晶度降低,淀粉的晶体结构被破坏,从而有助于吸水速率提升。综上,低温等离子体可以有效地改善糙米的蒸煮和食用品质,研究结果可为低温等离子在糙米生产中提供参数指导。 相似文献