On Zerotree Quantization for Embedded Wavelet Packet Image
Coding
N.M.Rajpoot1,2,F.G.Meyer3,R.G.Wilson1,and R.R.Coifman2
1Department of Computer Science,University of Warwick,Coventry,United Kingdom Department of2Mathematics and3Computer Science,Yale University,New Haven,CT
e-mail:rajpoot-nasir@https://www.doczj.com/doc/109175558.html,
Abstract
Wavelet packets are an e?ective representation tool for adaptive waveform analysis of a given signal.We ?rst combine the wavelet packet representation with zerotree quantization for image coding.A general ze-rotree structure is de?ned which can adapt itself to any arbitrary wavelet packet basis.We then describe an e?cient coding algorithm based on this structure.Fi-nally,the hypothesis for prediction of coe?cients from coarser scale to?ner scale is tested and its e?ective-ness is compared with that of zerotree hypothesis for wavelet coe?cients.
1Introduction
There has been a surge of interest in wavelet trans-forms for image and video coding applications,in re-cent years.This is mainly due to the nice localiza-tion properties of wavelets in both time(or space) and frequency.The zerotree quantization,proposed by Shapiro[8],is an e?ective way of exploiting the self-similarities among high-frequency subbands at vari-ous resolutions.The main thrust of this quantization strategy is in the prediction of corresponding wavelet coe?cients in higher frequency subbands at the?ner scales,by exploiting the parent-o?spring dependen-cies.This prediction works well,in terms of e?ciently coding the wavelet coe?cients,due to the statistical characteristics of subbands at various resolutions,and due to the scale-invariance of edges in high frequency subbands of similar orientation.Various extensions of zerotree quantization,such as[3,9],have been pro-posed ever since its introduction.
Wavelet packets[1]were developed in order to adapt the underlying wavelet bases to the contents of a signal.The basic idea is to allow non-octave subband decomposition to adaptively select the best basis for a particular signal.Results from various image cod-ing schemes based on wavelet packets show that they are particularly good in coding images with oscilla-tory patterns,a special form of texture.While wavelet packet bases are well adapted to the corresponding signal(image),one loses the parent-o?spring depen-dencies,or the spatial orientation trees,as de?ned in [8,7].
In this work,we address the following question: can the zerotree quantization be applied to wavelet packet transformed images?The question is valid since one does not generally observe as much self-similarities among the wavelet packet subbands as among the wavelet subbands.Moreover,even if there does exist self-similarity among wavelet packet sub-bands,the question arises:how would the spatial ori-entation trees,or zerotrees,be de?ned in order to pre-dict the insigni?cance of corresponding wavelet pack-ets at a?ner scale,given a wavelet packet at a coarser scale?The issue was addressed partially by Xiong et al.in[10].In their work,however,the tree decompo-sition was restricted not to have a basis causing the parenting con?ict,a problem described in the next sec-tion.We present a solution to this problem and de?ne a set of rules to construct the zerotree structure for a given wavelet packet geometry,thus o?ering a general structure for an arbitrary wavelet packet decomposi-tion.This generalized zerotree structure is termed as the compatible zerotree for reasons mentioned in the next section.The new tree structure provides an e?-cient way of encoding the wavelet packet coe?cients. We combine the idea of zerotree quantization with wavelet packet transforms for image coding purposes. 2Compatible Zerotree Quantization The wavelet packet basis[1]is adaptively selected in order to tailor the representation to the contents of a signal(an image,in our case).The nodes in a full subband tree(or short-term Fourier transform, namely STFT,tree)are pruned following a series of split/merge decisions using certain criterion(see[2] for entropy-based best basis selection and[6]for op-timizing the best basis from a rate-distortion view-point).Suppose the best basis has been selected us-
ing one of these methods.The issue is how to organize the spatial orientation trees so as to exploit the self-similarities,if any,among the subbands.The basis selected by any of the above methods does not,in gen-eral,yield the parent-o?spring relationships like those in wavelet subbands.Moreover,there can be an in-stance in the wavelet packet tree where one or more of the child nodes are at a coarser scale than the parent node.This results in the association of each coe?cient of such a child node to multiple parent coe?cients,in the parent node,giving rise to a parenting con?ict. To make the point clear,let us consider the segmen-tation shown in Figure1,for a3-level wavelet packet transform.The nodes C1,C2,C3,and C4at a coarser scale are children of the node P at a?ner scale.The problem with such a situation is that there are four candidates in P claiming the parenthood of the set of four coe?cients belonging to the four children nodes. In[10],the best basis was selected in such a way that whenever a con?ict like this arises,the four children are merged so as to resolve the con?ict.This subopti-mal approach constrains selection of the best basis at the loss of the freedom of adapting the wavelet packet basis to the contents of a particular
signal.
Figure1:Sample segmentation in a3-level wavelet packet decomposition and the parent-o?spring dependencies for compatible zerotree originating from T1.
We organize the zerotree structure,called compat-ible zerotrees,dynamically so that there is no restric-tion on selection of the wavelet packet basis(we call these the compatible zerotrees,since they are gener-ated taking into account both the scale and orientation compatibility).It is to be noted that the compatible zerotrees di?er from the spatial orientation trees of[7] in the sense that nodes of a compatible zerotree rep-resent a full subband,rather than one or more coe?-cients.We utilize the compatible zerotrees to?nd the coe?cients which are zerotree roots,for a given thresh-old.A set of rules is de?ned to construct the compati-ble zerotrees so that the overall zerotree structure can be constructed for any arbitrary wavelet packet basis. The only assumption made is that the basis has its lowest frequency bands at the coarsest scale.This is based upon the fact that a signi?cant amount of the signal energy is concentrated in the lowest frequency subbands,which cannot be merged by any of the tree pruning algorithms.
Let R denotes the node representing the lowest fre-quency subband,situated in the top-left corner of a conventional subband decomposed image.Then R represents the root node of overall compatible ze-rotree.It has three children(T1,T2,and T3as shown in Figure1)which represent the coarsest scale high-frequency subbands.These children are themselves root nodes of three compatible zerotrees with di?erent global orientations;horizontal,vertical,and diagonal respectively.These zerotrees are generated in a re-cursive manner(only once for a given wavelet packet basis)using the following set of rules,each of them applied to nodes with similar global orientation.
a)If a node P is followed by four nodes C1,C2,C3,
and C4(at the same scale),then P is declared to be the parent of all these four nodes.
b)If four subbands P1,P2,P3,and P4at a coarser
scale are followed by four subbands C1,C2,C3, and C4at immediately next?ner scale,then node P i is declared to be the parent of node C i(for i=1,2,3,4).
c)If a node P at a coarser scale is followed only by
a node C at the immediately next?ner scale(like
in a wavelet transform),the node P is declared as a parent of C.
d)If a node P is at a?ner scale than four of its
children,say C1,C2,C3,and C4,then P is disre-garded as being the parent of all these nodes and all this bunch is moved up in the tree.
Let us consider the segmentation shown in Figure1to explain these rules.The construction of?nal compat-ible zerotrees proceeds in two steps.In the?rst step, the primary compatible zerotrees T1,T2,and T3are constructed using rules a,b,and c,as shown in Figure 2.In the second step,the overall tree is re-organized (as shown in Figure3)using rule d,in order to resolve the parenting con?ict under node P.This rule?rst identi?es nodes with the parenting con?icts and when such nodes are found,the whole bunch(consisting of C1,C2,C3,and C4)is plucked from its current po-sition in the tree.The algorithm then climbs up the
tree to look for an appropriate node,a compatible an-cestor at the nearest scale and having the nearest ori-entation,and glues the bunch under this newly found compatible parent.The parent-o?spring dependencies for the primary compatible zerotree T1are shown in Figure1.For more details of the algorithm to con-struct the compatible zerotrees,please refer to[5].
Given an arbitrarily segmented wavelet packet ba-sis,the compatible zerotrees are constructed using the set of rules described as above.In order to be able to make predictions for wavelet packet coe?cients at ?ner scale subbands,the compatible zerotree hypothe-sis is de?ned as follows:If a wavelet packet coe?cient of a node from the compatible zerotree is insigni?cant, it is more likely that the wavelet packet coe?cients at similar spatial locations in all the descendent nodes of the same compatible zerotree will be insigni?cant as well.
We tested the success of compatible zerotree hy-pothesis,as de?ned above,for wavelet packets.The plots of wavelet packet coe?cients’amplitude against the coe?cient indices for the wavelet packet decompo-sition,using the entropy-based basis selection criterion as in[4],of a512×512Barbara image are shown in Figures4and5.The amplitude axis in both plots was restricted to±1000to facilitate the display of smaller coe?cients.While the subbands were arranged in an increasing frequency order for the plot in Figure4,the plot in Figure5refers to the subbands as organized in the compatible zerotrees.The three families of pri-mary compatible zerotrees T1,T2,and T3are clearly visible in the latter of these plots showing that the new arrangement was successful in isolating the coef-?cients of similar orientation in a hierarchy to be used for prediction in a top-down order.
3The Coder Algorithm
Once the compatible zerotrees have been generated, based upon knowledge of the best basis,the encod-ing takes place by repeatedly running the detection stage and the?ne-tuning stage until the bit budget is expired.Our algorithm requires only one list of detected coe?cients(LDC)to be maintained,as op-posed to two(three)lists kept by the EZW(SPIHT). The decoder?rst reads geometry of the best basis and generates the compatible zerotrees,and then proceeds by entropy decoding and interpreting the codewords (see[5]for more details of the algorithm).
4Experiments and Conclusions The idea of compatible zerotree quantization was coupled with the wavelet packet transform for pro-gressive image coding and its performance was tested against the fast adaptive wavelet packet(FAWP)[4] image codec algorithm.A comparison of the peak sig-nal to noise ratio(PSNR)achieved by CZQ and FAWP for three standard512×512images encoded at tar-get bit rates of0.25and0.10bits per pixel(bpp)is presented in Table1.While being relatively faster,by a factor ranging from two to four,than the bitplane coding of FAWP,the CZQ performs comparably well. We note that the e?ectiveness of zerotree quantization depends strongly upon the scale-invariance of edges among subbands of similar global orientation.The success of prediction of?ner scale coe?cients(set of all descendents D i at similar spatial location)based upon a given coe?cient i at a coarser scale is a func-tion of the conditional probability of D i being insigni?-cant,given i is insigni?cant.We compared the number of zerotree root nodes detected,for various values of threshold,both for wavelet and wavelet packet bases. It was observed that the probability of detection of the zerotree root nodes in a wavelet decomposition is far greater than that in a wavelet packet decomposition.
It is important to note here that the wavelet packet basis was selected by simply using?rst-order entropy as a criterion for the split/merge decisions.The coe?-cients of basis were,therefore,imposed to be zerotree quantized.As opposed to wavelets,the wavelet packet basis might not necessarily produce coe?cients that help towards success of the zerotree hypothesis(that is,produce more zerotrees).Figure6shows the geom-etry of wavelet packet basis selected for the512×512 Barbara image.In fact,we found that using the en-tropy as a criterion for the best basis selection might result into many coarse scale high frequency subbands (whose coe?cients represent oscillatory patterns in some parts of the image),as is clear from basis ge-ometry in Figure6.It is the encoding of coe?cients in these types of subbands which takes considerable amount of the bit budget for the following reason.If a coe?cient somewhere at the bottom of a compati-ble zerotree is found to be signi?cant,the signi?cance of all the corresponding coe?cients in sibling and the parent nodes needs to be encoded as well,even if some or most of them are insigni?cant.Our future work aims to look at the methods of optimizing the selec-tion of best basis using a criterion which results into optimal number of zerotrees and optimal distortion value,given the bit budget.Moreover,the ordering of wavelet packet coe?cients with respect to increas-ing frequency(that is,decaying magnitude)within the compatible zerotrees will provide a gain in the coding performance,by increasing the e?ciency of arithmetic coder to encode the zerotree codewords.
Figure 2:The overall compatible zerotree structure com-prising of the three primary compatible zerotrees T 1,T 2,and T 3;each node represents a whole wavelet packet sub-band,and the node radius is directly proportional to the support of wavelet packets at that transform
level.
Figure 3:The overall compatible zerotree structure,after
re-organization to resolve the parenting con?icts;the edge labels depict the rules used to generate the links between parent and the children
nodes.
Figure 4:Plot of wavelet packet coe?cients’amplitude
versus coe?cient indices for the wavelet packet decompo-sition of 512×512Barbara image;the subbands were ar-ranged in an increasing frequency
order.
Figure 5:Plot of wavelet packet coe?cients’amplitude
versus coe?cient indices for the wavelet packet decom-position of 512×512Barbara image;the subbands were organized in compatible zerotrees with the help of rules mentioned in Section
2.
Figure 6:Wavelet packet basis selected for the 512×512
Barbara image using ?rst-order entropy as selection crite-rion.
Rate (bpp)
FA WP
Fingerprint
26.68
0.10
23.81Goldhill
29.19
0.10
27.54
Lena
31.88
0.10
29.33
Acknowledgement
This work was supported in part by DARPA/AFOSR under Grant F49620-97-1-0011.
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[5]N.M.Rajpoot,F.G.Meyer,and R.R.Coifman,
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介词用法知多少 介词是英语中最活跃的词类之一。同一个汉语词汇在英语中可译成不同的英语介词。例如汉语中的“用”可译成：（1）用英语（in English）；（2）用小刀（with a knife）；（3）用手工（by hand）；（4）用墨水（in ink）等。所以，千万不要以为记住介词的一两种意思就掌握了这个介词的用法，其实介词的用法非常广泛，搭配能力很强，越是常用的介词，其含义越多。下面就简单介绍几组近义介词的用法及其搭配方法。 一. in, to, on和off在方位名词前的区别 1. in表示A地在B地范围之内。如： Taiwan is in the southeast of China. 2. to表示A地在B地范围之外，即二者之间有距离间隔。如： Japan lies to the east of China. 3. on表示A地与B地接壤、毗邻。如： North Korea is on the east of China. 4. off表示“离……一些距离或离……不远的海上”。如： They arrived at a house off the main road. New Zealand lies off the eastern coast of Australia. 二. at, in, on, by和through在表示时间上的区别 1. at指时间表示： （1）时间的一点、时刻等。如： They came home at sunrise （at noon, at midnight, at ten o’clock, at daybreak, at dawn）. （2）较短暂的一段时间。可指某个节日或被认为是一年中标志大事的日子。如： He went home at Christmas （at New Year, at the Spring Festival, at night）. 2. in指时间表示： （1）在某个较长的时间（如世纪、朝代、年、月、季节以及泛指的上午、下午或傍晚等）内。如： in 2004, in March, in spring, in the morning, in the evening, etc （2）在一段时间之后。一般情况下，用于将来时，谓语动词为瞬间动词，意为“在……以后”。如： He will arrive in two hours. 谓语动词为延续性动词时，in意为“在……以内”。如： These products will be produced in a month. 注意：after用于将来时间也指一段时间之后，但其后的时间是“一点”，而不是“一段”。如： He will arrive after two o’clock. 3. on指时间表示： （1）具体的时日和一个特定的时间，如某日、某节日、星期几等。如： On Christmas Day（On May 4th）, there will be a celebration. （2）在某个特定的早晨、下午或晚上。如： He arrived at 10 o’clock on the night of the 5th. （3）准时，按时。如： If the train should be on time, I should reach home before dark. 4. by指时间表示： （1）不迟于，在（某时）前。如：
初中英语介词用法归纳总结 常用介词基本用法辨析 表示方位的介词：in, to, on 1. in 表示在某地范围之内。 Shanghai is/lies in the east of China. 上海在中国的东部。 2. to 表示在某地范围之外。 Japan is/lies to the east of China. 日本位于中国的东面。 3. on 表示与某地相邻或接壤。 Mongolia is/lies on the north of China. 蒙古国位于中国北边。 表示计量的介词：at, for, by 1. at 表示“以……速度”“以……价格”。 It flies at about 900 kilometers an hour. 它以每小时900公里的速度飞行。 I sold my car at a high price. 我以高价出售了我的汽车。 2. for 表示“用……交换，以……为代价”。 He sold his car for 500 dollars. 他以五百元把车卖了。
注意：at表示单价(price) ，for表示总钱数。 3. by 表示“以……计”，后跟度量单位。 They paid him by the month. 他们按月给他计酬。 Here eggs are sold by weight. 在这里鸡蛋是按重量卖的。 表示材料的介词：of, from, in 1. of 成品仍可看出原料。 This box is made of paper. 这个盒子是纸做的。 2. from 成品已看不出原料。 Wine is made from grapes. 葡萄酒是葡萄酿成的。 3. in 表示用某种材料或语言。 Please fill in the form in pencil first. 请先用铅笔填写这个表格。They talk in English. 他们用英语交谈。 表示工具或手段的介词：by, with, on 1. by 用某种方式，多用于交通。 I went there by bus. 我坐公共汽车去那儿。 2. with表示“用某种工具”。
英语常用介词用法与辨析 ■表示方位的介词：in, to, on 1. in 表示在某地范围之内。如： Shanghai is/lies in the east of China. 上海在中国的东部。 2. to 表示在某地范围之外。如： Japan is/lies to the east of China. 日本位于中国的东面。 3. on 表示与某地相邻或接壤。如： Mongolia is/lies on the north of China. 蒙古国位于中国北边。 ■表示计量的介词：at, for, by 1. at表示“以……速度”“以……价格”。如： It flies at about 900 kilometers a hour. 它以每小时900公里的速度飞行。 I sold my car at a high price. 我以高价出售了我的汽车。 2. for表示“用……交换，以……为代价”。如： He sold his car for 500 dollars. 他以五百元把车卖了。 注意：at表示单价(price) ，for表示总钱数。 3. by表示“以……计”，后跟度量单位。如： They paid him by the month. 他们按月给他计酬。 Here eggs are sold by weight. 在这里鸡蛋是按重量卖的。 ■表示材料的介词：of, from, in 1. of成品仍可看出原料。如： This box is made of paper. 这个盒子是纸做的。 2. from成品已看不出原料。如： Wine is made from grapes. 葡萄酒是葡萄酿成的。 3. in表示用某种材料或语言。如： Please fill in the form in pencil first. 请先用铅笔填写这个表格。 They talk in English. 他们用英语交谈(from 。 注意：in指用材料，不用冠词；而with指用工具，要用冠词。请比较：draw in penc il/draw with a pencil。 ■表示工具或手段的介词：by, with, on 1. by用某种方式，多用于交通。如by bus乘公共汽车，by e-mail. 通过电子邮件。
The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because
页脚.
. . 教学过程 一、课堂导入 本堂知识是初中最常见的介词by的一个整理与总结，让学生对这个词的用法有一个系统的认识。页脚.
. . 二、复习预习 复习上一单元的知识点之后，以达到复习的效果。然后给学生一些相关的单选或其他类型题目，再老师没有讲解的情况下，让学生独立思考，给出答案与解释，促进学生发现问题，同时老师也能发现学生的盲点，并能有针对性地进行后面的讲课。 页脚.
. . 三、知识讲解 知识点1： by + v.-ing结构是一个重点，该结构意思是“通过……，以……的方式”，后面常接v.-ing形式，表示“通过某种方式得到某种结果”，即表示行为的方式或手段。 I practice speaking English by joining an English-language club. 我通过加入一个英语语言俱乐部来练习讲英语。 Mr Li makes a living by driving taxis.先生靠开出租车为生。 页脚.
. . 页脚. 介词by + v.-ing 结构常用来回答How do you...?或How can I...?之类的问题。 —How do you learn English? 你怎样学习英语呢？ —I learn English by reading aloud. 我通过大声朗读来学英语。 —How can I turn on the computer? 我怎样才能打开电脑呢？ —By pressing this button. 按这个按钮。 知识点2：by 是个常用介词，其他用法还有： 1【考查点】表示位置，意思是“在……旁边”，“靠近……”，有时可与beside互换。 The girls are playing by (beside) the lake. 女孩们正在湖边玩。 此时要注意它与介词near有所不同，即by 表示的距离更“近”。比较： He lives by the sea. 他住在海滨。 He lives near the sea. 他住在离海不远处。
The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中
at,in与on的用法 一、表示时间，注意以下用法： ①表示时间的某一点、某一时刻或年龄等用at。如： Igetupatsixinthemorning.我早上六点钟起床。 Hegotmarriedattheageof25.他25岁结婚。 ②泛指一般意义的上午、下午或晚上以及月或年等较长的时间，一般用in。如： WewatchTVintheevening.我们晚上看电视。 HewenttoJapanin1946.他于1946去了日本。 ③若表示星期几或某一特定的日期，则用on。如： HelefthereonthefifthofMay.他于5 月 5日离开这儿。 二、表示地点、场所、位置等，注意以下用法： ①表示某一点位置，用at。如： WeliveatNo87BeijingRoad.我们住在北京路87号。 Thehospitalisattheendofthestreet.医院在这条街的尽头。 与名词所有格连用表示地点，也用at。如： atmysister's在我姐姐家atthedoctor's在医务室 ②表示空间或范围，用in。如： What'sinthebox?这盒子里有什么? HelivesinPariswithhiswife.他同他妻子住在巴黎。 但有时两者可换用。如： Themeetingwasheldat[in]thehotel.会议在宾馆举行。 ③at与in的另一个区别是：at用于指较小的地方，而in用于指较大的地方。如： inShanghai在上海atthestation在车站 但是，大与小是相对的，有时随着说话者的着眼点不同，大地方也可能用at（比如把一个大地方看作一个点时）。如： OurplanerefuelledatLondon.我们的飞机在伦敦加油。 WestoppedforanhouratMoscowonourwaytoParis.我们在去巴黎的途中在莫斯科停了1个小时。 ④介词on用于地点，主要指在某物的表面。如： What'sonthetable?桌上有什么? There'sawalletlyingontheground.地上有个钱包。 【注】在少数搭配中，也用介词on。如： Heworksonafarm.他在农场工作。 三、在某些搭配中，三者的区别与英国英语和美国英语有关：
超全的英语介词用法归纳总结常用介词基本用法辨析 表示方位的介词：in, to, on 1. in 表示在某地范围之内。 Shanghai is/lies in the east of China. 上海在中国的东部。 2. to 表示在某地范围之外。 Japan is/lies to the east of China. 日本位于中国的东面。 3. on 表示与某地相邻或接壤。 Mongolia is/lies on the north of China. 蒙古国位于中国北边。 表示计量的介词：at, for, by 1. at 表示“以……速度”“以……价格”。 It flies at about 900 kilometers an hour. 它以每小时900公里的速度飞行。 I sold my car at a high price. 我以高价出售了我的汽车。 2. for 表示“用……交换，以……为代价”。 He sold his car for 500 dollars. 他以五百元把车卖了。 注意：at表示单价(price) ，for表示总钱数。
3. by 表示“以……计”，后跟度量单位。 They paid him by the month. 他们按月给他计酬。 Here eggs are sold by weight. 在这里鸡蛋是按重量卖的。 表示材料的介词：of, from, in 1. of 成品仍可看出原料。 This box is made of paper. 这个盒子是纸做的。 2. from 成品已看不出原料。 Wine is made from grapes. 葡萄酒是葡萄酿成的。 3. in 表示用某种材料或语言。 Please fill in the form in pencil first. 请先用铅笔填写这个表格。They talk in English. 他们用英语交谈。 表示工具或手段的介词：by, with, on 1. by 用某种方式，多用于交通。 I went there by bus. 我坐公共汽车去那儿。 2. with表示“用某种工具”。 He broke the window with a stone. 他用石头把玻璃砸坏了。注意：with表示用某种工具时，必须用冠词或物主代词。
【备战高考】英语介词用法总结(完整) 一、单项选择介词 1． passion, people won't have the motivation or the joy necessary for creative thinking. A．For . B．Without C．Beneath D．By 【答案】B 【解析】 【详解】 考查介词辨析。句意：没有激情，人们就不会有创新思维所必须的动机和快乐。A. For 对于；B. Without没有； C. Beneath在……下面 ; D. By通过。没有激情，人们就不会有创新思维所必须的动机和快乐。所以空处填介词without。故填without。 2．Modern zoos should shoulder more social responsibility _______ social progress and awareness of the public. A．in light of B．in favor of C．in honor of D．in praise of 【答案】A 【解析】 【分析】 【详解】 考查介词短语。句意：现代的动物园应该根据社会的进步和公众的意识来承担更多的社会责任。A. in light of根据，鉴于；B. in favor of有利于，支持；C. in honor of 为了纪念；D. in praise of歌颂，为赞扬。此处表示根据，故选A。 3．If we surround ourselves with people _____our major purpose, we can get their support and encouragement. A．in sympathy with B．in terms of C．in honour of D．in contrast with 【答案】A 【解析】 【详解】 考查介词短语辨析。句意：如果我们周围都是认同我们主要前进目标的人，我们就能得到他们的支持和鼓励。A. in sympathy with赞成；B. in terms of 依据；C. in honour of为纪念； D. in contrast with与…形成对比。由“we can get their support and encouragement”可知，in sym pathy with“赞成”符合句意。故选A项。 4．Elizabeth has already achieved success_____her wildest dreams. A．at B．beyond C．within D．upon
定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...
英语介词in、on、at等的用法大全 “表时间的介词at、on、in到底怎么用？”，今天接着跟大家分享这三个介词表时间的用法。 一、at 1、表示时刻，即几点几分（with particular points on the clock） I’ll see you at five o’clock. （我五点和你见面。） 2、表示一天中的某个时间段（with particular points in the day） The helicopter took off at midday and headed for the island. （直升机中午起飞，飞往那个岛屿。） 3、表示一周中的某个时间段，即工作日（weekday）和周末（weekend）（with particular points in the week） What are you doing at the weekend? 4、表示某种特殊场合，如名字中不含day的节假日（with special celebrations） At the New Year, millions of people travel home to be with their families（到了新年，成百上千万的人会回到家里和家人团聚。） 例外情况：如果是说在生日那天，不用at，而用on，因为生日那天是指具体日期，请往下参考on 的用法。 【注意】
如果是用what time来提问，what time前面一般不用at。如：What time are you leaving? （你几点走？）但是在口语中也可以这么问：At what time are you leaving? 二、on 1、用在日期前（with dates） We moved into this house on 2 October 1997. （我们是1997年10月2日搬进这栋房子的。）2、用在星期的单数前（with a singular day of the week to refer to one occasion） I’ve got to go to London on Friday. （我周五就到伦敦了。） 3、用在星期的复数前（with a plural day of the week to refer to repeated events） The office is closed on Fridays. （办公室周五是关门的。） 特殊情况：口语中有时会省略on，如：Do you work Saturdays? （你周六上班的吗？） 4、用在特殊日子前（with special dates） What do you normally do on your birthday? （你生日那天一般都做些什么？） 三、in 1、用在一天中的某个时间段前，一般为固定用法（with parts of the day） I’ll come and see you in the morning for a cup of coffee. （我上午来看你，一起喝杯咖啡。）2、用在月份前（with months）
介词的用法总结归纳 一、 In 介词 prep. 1.(表示位置)在…里面; 在, 于; 在…部位上 I could feel the tension in the room.我可以感觉到房间里的紧张气氛。 They live in France.他们住在法国。 2.(表示时间)在…时期, 在…之后, 在过程中 In her twenties and thirties she had had no difficulty getting jobs. 她在二三十岁时找工作一点也不困难。 I cannot see you now, e back in half an hour.我现在不能见你, 半小时后回来。 3.(表示方向)往…内, 朝…方向 I saw him go in the shop.我看到他走进了商店。 4.(表示状态)处于…之中, 在…情况下 Martin was in his pyjamas.马丁穿着睡衣。 They were living in terrible poverty.他们生活在极度贫困之中。 5.(表示方式)用, 以, 按, 乘, 以…形式 They were speaking in Italian.他们在讲意大利语。 They went up in the lift.他们乘电梯上楼了。
6.(表示原因)由于, 为了 He went in fear of his life.他为自己的性命担忧, 所以走了。 7.(表示领域, 范围)在…以内 It is not in my power to do that.做那事非我力所能及。 8.(表示结果)当做, 作为 What did you give him in return?你给他什么作为报答呢? 9.(表示目的)为了 They set off in search of the lost child.他们出发去寻找走失的孩子。 10.[表示职业、活动等]从事于，参加 11.[表示数量、程度、比例]按，以;从…中 12.[表示品质、能力等]在…之中;在…身上 I don't think he had it in him.我认为他没这个本事。 二、Into 介词 prep. 1.(表示时间)持续到, 进行到 The meeting carried on into the afternoon.会议一直延续到下午。 2.(表示方向)进入…中, 到…里 Anney dived into the water.安尼潜入水中。 He came into the room.他到房子里面。 3.(表示状态)进入…状态, 欠…债
“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法
不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.
初中英语介词用法归纳整理 表示时间的介词 at：用于表示时刻，时间的某一点。 on:用于星期，某天，某一天的上午，下午，晚上指具体的某一天时，一律用on in:用于表示周，月，季节，年，泛指上午，下午，晚上 before:在...之前 after:在...之后 by:在....前时间截止到... untiltill：直到.....为止 for：达...之久表示过了多少时间 during：在....期间 through：一直..从开始到结束 from：从...起时间 since:自从...以来表示从以前某时一直到现在仍在继续 in：过...后未来时间 within：不超过...的范围 表示场所，方向的介词 at :在某地点表示比较狭窄的场所 in:在某地表示比较宽敞的场所 on:在...上面，有接触面 above：在...上方 over：在...正上方，是under的反义词 under：在..下面，在...之内 below :在...下方不一定是正下方
near：近的，不远的 by:在...的旁边，比near的距离要近 between：在两者之间 among：在三者或者更多的之中 around：环绕，在...的周围，在....的四周 in front of:在...的前面 behind：在...后边 in：在..之内，用于表示静止的位置 into：进入 out of :和into一样，也表示有一定的运动方向 along：沿着 across：横过平面物体 through：贯通，通过 to :达到..地点目的地或方向 for：表示目的，为了..... from：从...地点起 其他介词 with：和..在一起; 具有，带有; 用某种工具或方法 in：表示用什么材料例如：墨水，铅笔等或用什么语言。表示衣着.声调特点时，不用with而用in。 by:通过...方法，手段 of:属于...的，表示...的数量或种类 from：来自某地，某人，以...起始 without：没有，是with的反义词 like :像...一样
英语介词用法详解 一、单项选择介词 1．“May I help you?”Said a bright American voice _____ the telephone. A．in B．over C．from D．of 【答案】B 【解析】 分析句意，可知这是从电话的另外一端所讲的话。在英语的习惯中，要用介词over。根据句意，可知选B。句意：“我有什么能帮你的呢？”从电话的另外一端传过来一把响亮的美国口音。 2．All of us want to go to the park ___________ Bob. He had to look after his sick mother at home. A．except B．besides C．except for D．in addition to 【答案】A 【解析】 【详解】 考查介词和介词短语辨析。句意；除了鲍勃，我们都想去公园。他不得不在家照顾生病的母亲。except后接的词同整体词（主语）一般是同类，指在同类的整体中除去一个部分；besides除……之外还有；except for后接的词同句子中的整体词（主语）不是同类的，指从整体中除去一个细节，一个方面；in addition to除……之外还有。根据句意可知，鲍勃没有和我们一起去，而且与主语是同类，故选A。 3．The police are reopening the investigation ________ the new evidence. A．in tune with B．in conflict with C．in light of D．in place of 【答案】C 【解析】 【详解】 考查固定短语。句意：警方正根据新的证据重新展开调查。A. in tune with与……一致；B. in conflict with和……冲突；C. in light of根据，鉴于；D. in place of代替。分析句子可知，应该根据新证据重新调查，故选C。 4．As is known to all, the law requires equal treatment for all, ________ race, religion, or gender. A．in spite of B．in terms of C．regardless of D．in virtue of 【答案】C 【解析】 【详解】
表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法
后”： I ' ll see you aga in with in three days. 3 I ' ll see you again after three days. 3 Look, there ' s a hole on the wall.介词in 重要用法归纳 介词in 用法比较复杂，以下几点比较重要，须引起注意： 1.表示时间，表示“在……后”，注意它与after 的区别：虽然两者均可与一段时间连用， 表示多久之后，但in 以现在时间为起点，表示从现在起多久以后，通常用于将来时态或 含有将来意味的句子；而 after 则以过去或将来时间为起点，表示从那以后。如： I ' II come back in five minutes. 我5分钟后就回来。（以现在时间为起点） He came back after five minu tes. 5 分钟后他就回来了。（以过去时间为起点） 但是，若after 后接的不是一 “段”时间，而是一 “点”时间，则完全可以现在时间为起点。 如： I ' ll come back after five o ' clock. 我 5点钟以后回来。 不过，在现代英语中，以上规则有时被打破。如: I may come after a day or two. 我可能过一两天会来。 Wang Bing is leavi ng the USA after two days. 两天后王兵要离开美国。 2.类似in three days 这样的短语，有时含义不易确定，因为它既可表示“ 3天内”， 也可表示“ 3天后”，大致可以这样区分：若与延续性动词连用，则表示“ 3天内”，若与 非延续性动词连用，则表示“ 3天后”。如: He lear nt En glish in three weeks. 他在3周内学会了英语。 The train will arrive in a few minu tes. 火车过几分钟就到。 但语言的实际并不完全是这样，有时需视具体的上下文或语境来确定。如: We should be able to complete the work in five days. 我们应该能在 5天内完成这工 作。 为了明确语义，有时人们就分别用 within 和 after 来表示“在……内”和“在 3. 表地点、位置、范围、空间等，注意不要混淆 in 与on 的用法。如: 瞧, 墙上有个 洞。 天内我再来看你。 天后我再来看你。 误: 正: Look, there s a hole in the wall.