查询词典 compression

In this technique, K-L transformation was used to remove spectral statistic correlation on the spectral direction. Then SNMAW prediction tree technique was used to remove spatial correlation and spectral structure correlation. With the limit of a certain max error, this technique can get a higher compression ratio. 6. We proposed a lossy compression technique based on wavelet transformation with sharing significance map.

该方法在谱维方向进行K-L变换，有效地去除谱间统计冗余，而变换后的图象仍存在空间相关性和谱间结构相关性，再利用改进的预测树方法方法进行无损压缩，在最大误差很小的限制下，得到较高的压缩效率。

Through the analysis of characteristics in curve of deformation tests on the four kinds of rockmasses such as claystone, siltstone, feldspar-quartz sandstone and lithic sandstone underlain the dam foundation of Tingzikou Hydropower Station, it is thought that: the test deformation of thick lithic sandstone is mainly caused by slippage deformation of rock crystal lattice ; the test deformation of feldspar-quartz sandstone is mainly from small crevices in rock, compressive deformation of rock small holes and slippage deformation of rock crystal lattice; and the test deformation of thin layer claystone in which horizontal layer is developed and siltstone is mainly from compression deformation in interlayer, small crevices in rock, compression deformation of rock small holes and slippage deformation of rock crystal lattice.

通过对亭子口水利枢纽工程坝基下卧的黏土岩、粉砂岩、长石石英砂岩和岩屑砂岩等 4 种主要岩性的岩体变形试验曲线特征进行分析，认为：厚层岩屑砂岩的试验变形量主要来自于岩石晶格错动变形，长石石英砂岩的试验变形量主要为岩石内孔隙和空隙变形以及岩石晶格错动产生的变形，而层理较发育的薄层黏土岩和粉砂岩的试验变形量主要由层间压缩变形、岩石内孔隙和空隙变形以及岩石晶格错动产生的变形共同组成。

Finally, the physical index and compression index of silty soil from Yangtze Basf project are divided to three groups according to depth, then characteristic statistic are calculated to physical and compression index of three groups and mechanical index of all depths. After that, normal distribution 、 logarithmic normal distribution and extreme I distribution are fitted for physical and mechanical indexes. And Goodness-of-fit testing with X~2 method is done subsequently.

最后，将扬子巴斯夫工程粉质粘土的物理指标和压缩性指标按照埋深分为三组，计算了不同深度上粉质粘土的物理指标和压缩性指标以及所有深度上抗剪强度指标的特征统计量；然后用正态分布、对数正态分布和极值I型分布对各指标进行概率模型拟合并用x~2法对拟合优度进行了检验。

Comparing with lossy image compression, the lossless image compression is more difficult and its development is slower.

图像的无损压缩相对有损压缩来说更加困难，取得的进展也更小。

The algorithm of SAR image's lossless compression and low loss compression is discussed.

对SAR图像的统计特性进行了研究，据此对SAR图像的无失真压缩、低失真压缩进行了理论研究。

The methods of image compression could be summed up as the lossy and loseless compression.

图像压缩的方法很多，但一般可分为有损压缩和无损压缩两大类。

Comparing with lossy image compression, the lossless image compression is more difficult and itsdevelopment is slower.

图像的无损压缩相对有损压缩来说更加困难，取得的进展也更小。

Lossy compression on the other hand allows some loss, but has the potential for much higher compression rates.

损失性图像压缩则允许某些图像信息丢失，但在压缩比上有着更大的潜力。

The main work and innovation1 In general , a image compression method has different effect to different image . Some are fit for image which has much high frequency . Some are fit for image which has much low frequency .This paper analysis the applicability of fractal algorithm . In this dissertation , an improved algorithum is given . The basic algorithum without eight change and the joint use of quantitative coding , The compression ratio and PSNR can be adjusted , and it can get more quickly speed of coding .2 To a group of exact fractal code , the decoding image can be any resolution .With this characteristic ,choose the proper domain block and range block,this paper get an algorithum which can get higher decoding PSNR and speed than the basic fractal algorithum.3 Give a new method to calculate the scale factor . The calculation of basic algorithum is complex and enormous . The factor of scale is an important variable of the basic algorithm. Now there are two methods to calculate the factor of scale .A new method was given to calculate the factor of scale. The calculation load and complexity are reduced by the new method. Compared with the basic algorithm , the method can reduce coding time.4 The basic fractal algorithum is based on the Collage theorem and contraction mapping theorem . A mathematic model based on basic fractal algorithum is given .

本文的主要工作及创新点主要包括以下几点：1一般情况下，一种图像压缩的方法对不同特点的图像，压缩效果会有所不同，本文利用分形压缩编码对不同特点的图像进行编码，分析了分形编码对不同图像的编码适用性，利用去掉8种变换的分形编码算法与简单的均匀量化编码方案相结合，得到了一种可以调节压缩比与解码质量的分形编码方案，该提高编码速度6倍以上。2分形编码的特点之一是分形解码的分辨率无关性，即对于一组分形编码可以将其解码到任意分辨率下，本文利用分形编码的这一特点，结合不同的量化编码方案，选择合适的定义域块与值域块及适当的编解码分辨率，得到了一种提高解码质量，编码速度提高12倍以上的加速算法。3比例因子是基本分形算法中的一个重要变量，目前有两种计算比例因子的方法，文中给出了一种新的求比例因子的方法，该方法简化了求比例因子的计算，从整体上减小了基本分形算法的计算量，简化了算法4分形压缩的数学基础是不动点定理与拼贴定理，本文根据基本的自动分形编码方法，建立数学模型对其进行推导，得到了用普通数学的极限理论解释分形编码的数学表达式，从而对由基本分形编码得到的解码图像中的像素点的值给出了确定的表达式。

In the wet compression process the evaporation model of water droplets was established. Based on mentioned above multi elemental section constant pressure mathematical models for actual wet compression processes was established.

且在了解湿压缩过程中的液滴蒸发速率、蒸发时间等基本理论的基础上建立了湿压缩过程的等压微元段的实际湿压缩的数学模型。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。