计算机专业英语教案--25[3页]

教材名称：《计算机专业英语》主编：来永春出版时间：电子教案第25次课学时2授课题目（章，节）ProjectFiveBeautifyingtheOnlineStorePagePartATheoreticalLearningSkillOneAShortIntroductiontoMultimedia授课类型（请打√）理论课□√研讨课□习题课□复习课□其他□教学目的：1Inthispart,ourtargetistoimprovethespeedofreadingprofessionalarticlesandthecomprehensionabilityofthereader.2.Wehavemarkedspecializedvocabularykeywordsinsomeparagraphssothatthereadercanquicklygraspthemainideaofthesentencesandparagraphs.教学方法、手段：1.Bythecomputer,projectorandblackboard-writing2.Bythestudent-centeredlearning,usingClassroomTeachingMethod,CommunicativeTeachingMethod,Task-basedTeachingMethodandAudio-visualTeachingMethod教学重点、难点：1.Masterthekeywordsandphrasesinthetext.2.Cananalyzethestructureofthecomplexsentencesinthetext.3.CantranslatethetextintoChinesewiththehelpofthereferencematerials.3.CandescribeAShortIntrodutiontoMultimedia教学内容及过程设计补充内容和时间分配教学设计Step1.Learningkeywordsandphrasesaudion.音频animationn.动画videon.视频compressionn.压缩framen.帧algorithmn.算法pixeln.像素JPEG(JointPhotographicExpertsGroup)abbr.联合图像专家组MPEG(MotionPictureExpertsGroup)abbr.运动图像专家组rectangularadj.矩形的gridn.网格Step2.Introductionoftrainingtarget1Inthispart,ourtargetistoimprovethespeedofreadingprofessionalarticlesandthecomprehensionabilityofthereader.2.Wehavemarkedspecializedvocabularykeywordsinsomeparagraphssothatthereadercanquicklygraspthemainideaofthesentencesand20分钟5分钟paragraphs.Step3.LeadinginashortintroductiontoMultimediaInfact,multimediaisjusttwomedia:soundandpictures.Itismadefromamixofhardwareandsoftware,ormachineandideas.Itpresentsinformation,sharesideasandevokesemotions.Itenablesyoutosee,hear,andunderstandthethoughtsofothers.Step4.Analyzingthestructureofthecomplexsentences1.Multimediaisakindofcomputertechnologythatcombinestext,audio,staticgraphicimages,animations,andfull-motionvideo.2.Audioreferstosoundortothingswhichcanbeheard.Usually,thehumanearcanheararangeoffrequenciesbetweenaround20Hz~20KHz.3.AmajorgoaloftheMPEG-2videostandardistodefinetheformatofthevideodatawhichistobetransmitted.Step5.Memorizingandmasteringthefollowingkeysentencesinthetext.1.Youcanmakeitdowhatyouwantittodo.That’sthestrengthofmultimedia.2.Computersoftwarecaneasilyprocessdigitizedsound.Virtually,allprofessionalsoundsofrecordingandeditingaredigitalnowadays.3.JPEGimage-compressionstandardandfileformatdefineasetofcompressionmethodsforhigh-qualityimages,suchasphotographs,singlevideoframesorscannedpictures.4.JPEGdoesnotworkverywellwhencompressingtext,lineartorvectorgraphics.5.MPEGstandardsarethemainalgorithmsusedtocompressvideoandhavebecomeinternationalstandardsince1993.6.IfthecompressiontechniquesareusedinMPEG-2,thentheyaretoalargeextentbasedonsomeknowledge.7.Theknowledgeisthatwehaveabouthowthehumaneyeandthevisualcentersinthebrainrecognizeimages.8.Sofar,thecapabilitiesofthehumaneyetorecognizeimageshavebeendescribed.9.Therearetwomajorcolorspacestypesusedindigitalvideo:RGBandYUV.RGBiscommonlyusedincomputerenvironments,whileYUVisrelatedmoretothetelevisionworld.`10.Thesimplestrepresentationofdigitalvideoisasequenceofframes,eachconsistingofarectangulargridofpictureelementsorpixels.11.Eachpixelcanbeasinglebittorepresenteitherblackorwhite,using8bitsperpixeltorepresent256graylevels.12.Forcolorvideo,goodsystemsuse8bitsforeachoftheRGBcolors.24bitsperpixellimitsthenumberofcolorstoabout16millionStep6.Summarizinginclass.5分钟15分钟45分钟思考题、作业题、讨论题：1.Reviewthekeywordsandphrasesinthetext.2.CantranslatethetextintoChinesewiththehelpofthereferencematerials.3.Completetheexercisesinvolved.课后总结分析：