自适应多值量化的亚抽样块截断编码

本文报道了一种新的活动图像编码算法,称为自适应多值量化的亚抽样块截断编码。模拟结果表明:这种新算法比现有的其它同类算法有更好的性能,压缩比为30,信噪比为35.4dB,图像主观质量良好,在现有个人计算机上可以用软件实时实现。

一种保护图象轮廓细节的自适应亚抽样和插值方法

为在图象编码时减少原始图象数据 ,以提高压缩比和编码速度 ,提出了一种新的自适应亚抽样与插值的方法及可应用于多类分块图象编码的算法 .该方法首先将图象划分成互不重叠的块 ,然后计算每个块的水平梯度与竖直梯度 ,再根据图象块的两个方向梯度值 ,将图象块分为平滑块、水平轮廓块、竖直轮廓块和高细节块等 4类 ,同时对每类图象块采用不同的亚抽样与插值方法以减少原始图象数据 .模拟结果表明 :相对于其它的亚抽样与插值方法 ,该算法能够很好地保护图象中的轮廓及细节信息 ,从而极大地提高了重建图象的质量 ,尤其是图象的主观质量 .另外 ,对于细节较多的图象 ,该算法在保持相当压缩比的同时 ,PSN R也提高了 3.9d B;而对于细节较少的图象 ,压缩比与 PSN

亚抽样方法在HDTV子编码器码率分配中的应用

由于现存硬件条件的局限,高清晰度电视视频编码的硬件实现只能通过数片SDTV级的编码芯片来完成,其子编码器的码率分配会影响整个编码器的图家编码质量。实验表明,平均分配码率存在着子图的码率分配与其活动性不匹配的弊病,为此,我们提出了一种基于亚抽样的码率分配方法。在对Basketball序列的软件模拟结果显示,该方法提高了图象编码质量的一致性,其编码子图的PSNR最大差值比平均分配码率方法减少了6dB。

Evaluation of Metal Contamination of Mullet （Mullus surmuletus L., 1758） in the Bay of Oran

The present study focused on the evaluation of the contamination by three heavy metals （Cd, Cu and Zn） of a bony fish, Mullus surmuletus L., 1758, caught in the Bay of Oran. This reflects the quality of fish habitat as species common Algerian coastal waters and enjoyed by a large fish-eating population. Monthly sampling was spread over a period of six months （December 2011-May 2012）. Given their physiological importance in the body, muscle, liver and gonads were targeted. Metal concentrations were determined by atomic absorption spectrophotometry in flame depends on three parameters （sex, size and month）. It appears from this study that the target organs of rouget （M. surmuletus） accumulate three metal pollutants sought. The highest values are those of zinc, copper and cadmium are at concentrations at least important. The results, statistically treated, showed no significant difference between the concentrations of trace metals both sexes and at all three organs considered. The average dose of heavy metals found in the mullet compared to those provided by the literature relating to DMA （Maximum Allowable Doses）, are not worrisome. Concentration levels of toxic metals reflect a certain metal pollution in the Bay of Oran.

The Perception of Small- and Medium-Sized Enterprises （SMEs） on the Importance of a Proper Accounting System： Malaysian Evidence

This paper examines the relationship between small- and medium-sized enterprises＇ （SMEs） entrepreneurs＇ perceptions towards a proper accounting system with the level of accounting staff recruited, preparation of final accounts, meetings with accounting staff, and entrepreneurs＇ ranking of accounting according to their priority. The methodology used to gather the data is survey questionnaire. It has been distributed to SMEs based on simple random sampling method. Three hundred businesses were selected from the total of 3,390 businesses listed in Kuala Lumpur, Malaysia area obtained from Small and Medium Industries Development Corporation （SMIDEC） website and a few random selected from Ampang and Cheras areas. Regression analysis has been used to analyze the data. The results of the study reveal that there was a significant relation between SMEs entrepreneurs＇ perceptions on the importance of a good accounting system and the level of professional accounting staff recruited. Furthermore, findings of this study also found that there was an insignificant relationship between SMEs entrepreneurs＇ perceptions on the importance of a good accounting system and preparation of final accounts of the company and frequency of meetings with accounting staff.

图像压缩编码技术及其发展

随着微电子技术和计算机技术日新月异的发展,数字技术在各个领域得到广泛应用,在此基础上网络技术孕育而生。

建议H.120——用于数字基群传输的电视会议编译码器

【正】 CCITT考虑到: (a)要求电视会议服务的用户日益增多; (b)目前,可以通过数字基群信道提供有效的电路来满足这种要求; (c)由于在世界各地存在不同的数字体系和不同的电视标准,使规定国际间互连的编码和传轴标准问题复杂化; (d)应该考虑最终使用数字交换传输网络; 意识到: 视频编码和比特率压缩技术的研究和开发进展迅速。在随后的研究期间可能提出进一步有关384 kbit/s倍数或约数比特速率的电视会议的建议,因而这一建议可作为不断发展的建议系列的第一个建议;还注意到: CCITT的基本目标是尽可能对国际间的互连建议唯一的解决方案;建议: 后面第1部分、第2部分和第3部分说明的具有信号处理和接口特性的编译码器应该被用于国际间的电视会议互连。注意:不排除这个建议之外的编译码器类型。