《无人机行业应用（双语）》课件-16.正射影像图与数字表面模型生成

正射影像图与数字表面模型生成-Orthophotoimagesanddigitalsurfacemodelgeneration--《无人机行业应用》-"UnmannedAerialVehicleIndustryApplications"Keyknowledge重点知识掌握这两种数字产品的生成原理、制作流程和质量控制要点Masterthegenerationprinciples,productionprocessesandkeypointsofqualitycontrolofthesetwodigitalproducts实现从原始数据到标准成果的完美转化Achieveaperfecttransformationfromrawdatatostandardachievements壹正射影像图生成技术Orthophotoimagegenerationtechnology正射影像图生成技术Orthophotoimagegenerationtechnology正射影像图是经过几何校正、具有统一坐标系统的影像地图。Anorthophotomapisanimagemapthathasundergonegeometriccorrectionandhasaunifiedcoordinatesystem.Theprojectiondifferencecausedbyundulatingterrainandcameratilthasbeeneliminated消除了因地形起伏和相机倾斜引起的投影差Ithasachievedanexpressioneffectaspreciseasamap实现了"像地图一样精准"的表达效果制作过程融合了摄影测量与数字图像处理的核心技术。Theproductionprocessintegratesthecoretechnologiesofphotogrammetryanddigitalimageprocessing.正射影像图生成技术Orthophotoimagegenerationtechnology生成正射影像图的首要步骤是数字微分纠正。Thefirststepingeneratinganorthophotomapisdigitaldifferentialcorrection.基于空三加密成果和数字表面模型，逐像素计算影像的正确位置。Basedonthespace-threeencryptionresultsandthedigitalsurfacemodel,thecorrectpositionoftheimageiscalculatedpixelbypixel.正射影像图生成技术Orthophotoimagegenerationtechnology生成正射影像图的首要步骤是数字微分纠正。Thefirststepingeneratinganorthophotomapisdigitaldifferentialcorrection.在大疆智图中，我们需要设置合适的采样间隔，通常建议使用默认的像元尺寸倍数，以平衡精度和效率。InDJIMap,weneedtosetanappropriatesamplinginterval.Itisusuallyrecommendedtousethedefaultpixelsizemultipletobalanceaccuracyandefficiency.正射影像图生成技术OrthophotoimagegenerationtechnologyColorbalanceprocessing色彩均衡处理Whenshooting,changesinlightingconditionsmaycausecolordifferencesandbrightnessvariationsbetweenadjacentimages拍摄时光照条件变化，相邻影像间可能存在色差和亮度差异Thesoftwarewillautomaticallyperformcolortonematchingandeliminateseammarks软件会自动进行色调匹配，消除接缝痕迹正射影像图生成技术OrthophotoimagegenerationtechnologyColorbalanceprocessing色彩均衡处理手动调整均衡化强度，在自然过渡和细节保留之间找到最佳平衡。Manuallyadjusttheintensityofequalizationtofindthebestbalancebetweennaturaltransitionsanddetailretention.正射影像图生成技术OrthophotoimagegenerationtechnologyColorbalanceprocessing色彩均衡处理对于大面积单一地物区域，建议适当降低处理强度，避免纹理失真。Forlargeareasofsinglegroundobjects,itisrecommendedtoappropriatelyreducetheprocessingintensitytoavoidtexturedistortion.正射影像图生成技术OrthophotoimagegenerationtechnologyInlaylineeditingstage镶嵌线编辑环节智能算法会自动寻找最佳镶嵌路径。TheintelligentalgorithmwillautomaticallysearchforthebestMosaicpath.Avoidbuildings,treesandothergroundobjectstoreducetheinfluenceofprojectiondifferences避开建筑物、树木等地物，减少投影差影响对于自动生成不满意的区域；Fortheautomaticallygeneratedunsatisfactoryareas;可以手动编辑镶嵌线，确保重要地物完整且无重影。TheMosaiclinescanbemanuallyeditedtoensurethatimportantfeaturesareintactandfreeofghosting.贰数字表面模型制作Digitalsurfacemodelmaking数字表面模型制作DigitalsurfacemodelmakingThefoundationofthree-dimensionalspatialanalysis三维空间分析的基础数字表面模型反映了地表及其上所有地物的高程信息。Digitalsurfacemodelsreflecttheelevationinformationoftheearth'ssurfaceandallthefeaturesonit.生成质量直接影响正射影像图的精度和后续应用的可靠性。Thegenerationqualitydirectlyaffectstheaccuracyoftheorthophotoimageandthereliabilityofsubsequentapplications.数字表面模型制作DigitalsurfacemodelmakingDSM生成的核心是密集匹配技术。ThecoreofDSMgenerationisdensematchingtechnology.Thesoftwarewillbebasedonthenullthreeencryption软件会在空三加密的基础上在影像重叠区域进行高密度特征点匹配，构建数倍于空三连接点的密集点云。High-densityfeaturepointmatchingiscarriedoutintheoverlappingareaoftheimagetoconstructadensepointcloudseveraltimesthatofthespatialtripleconnectionpoints.数字表面模型制作DigitalsurfacemodelmakingDSM生成的核心是密集匹配技术。ThecoreofDSMgenerationisdensematchingtechnology.Thesoftwarewillbebasedonthenullthreeencryption软件会在空三加密的基础上匹配程度设置是关键参数，较高程度能获得更丰富的细节，但计算时间会显著增加。Thematchingdegreesettingisakeyparameter.Ahigherdegreecanobtainricherdetails,butthecalculationtimewillincreasesignificantly.数字表面模型制作Digitalsurfacemodelmaking在滤波处理环节，我们需要根据地物特征选择合适的算法。Inthefilteringprocessingstage,weneedtoselectanappropriatealgorithmbasedonthecharacteristicsofthegroundobjects.Fordenselybuilt-upareas,afilteringalgorithmthatretainstheedgeisadopted对于建筑密集区，采用保留边缘的滤波算法Forareaswithundulatingterrain,afilteringmethodwithsmoothtransitionsisused对于地形起伏区域，使用平滑过渡的滤波方式这个过程需要反复调试，既要消除匹配噪声，又要保留真实的地物边缘。Thisprocessrequiresrepeateddebugging,whichisnecessarytoeliminatematchingnoisewhilepreservingthetrueedgesofthegroundobjects.数字表面模型制作Digitalsurfacemodelmaking成果输出时需要设置合适的分辨率Whenoutputtingtheresults,anappropriateresolutionneedstobesetTheresolutionofDSMshouldbeconsistentwiththatoftheorthophotoimageDSM分辨率应与正射影像图保持一致通常选择与原始影像地面分辨率相同或稍低的设置。Usually,asettingwiththesameorslightlylowergroundresolutionastheoriginalimageischosen.同时要注意设置正确的数据格式和坐标系统，确保与其他测绘成果的兼容性。Atthesametime,itisnecessarytopayattentiontosettingthecorrectdataformatandcoordinatesystemtoensurecompatibilitywithothersurveyingandmappingresults.叁成果质量与应用Qualityofachievementsandapplication成果质量与应用Qualityofachievementsandapplication成果质量检查是确保产品可用的最后关口。Thequalityinspectionoftheoutcomeisthefinalcheckpointtoensuretheusabilityoftheproduct.Geometricaccuracy几何精度Colorconsistency色彩一致性Integrity完整性通过对比已知控制点坐标，验证平面位置精度。Theplanarpositionaccuracyisverifiedbycomparingtheknowncontrolpointcoordinates.通过目视检查，确认色彩过渡自然、无接缝痕迹。Throughvisualinspection,confirmthatthecolortransitionisnaturalandseamless.通过叠加检查线，确保全域覆盖无漏洞。Bysuperimposinginspectionlines,ensurefullcoveragewithoutanyloopholes.成果质量与应用QualityofachievementsandapplicationDSM的质量评估更为复杂。ThequalityassessmentofDSMismorecomplex.除了检查高程精度外，还需要重点检查地物边缘的保真度。Inadditiontocheckingtheelevationaccuracy,itisalsonecessarytofocusoninspectingthefidelityoftheedgesofthegroundobjects.Whethertheoutlineofthebuildingisclear建筑物轮廓是否清晰Whethertheroofstructureisintact屋顶结构是否完整Whetherthevegetationareaisoverlysmooth植被区域是否过度平滑这些都是评价DSM质量的重要指标。TheseareallimportantindicatorsforevaluatingthequalityofDSM.成果质量与应用QualityofachievementsandapplicationDSM的质量评估更为复杂。ThequalityassessmentofDSMismorecomplex.除了检查高程精度外，还需要重点检查地物边缘的保真度。Inadditiontocheckingtheelevationaccuracy,itisalsonecessarytofocusoninspectingthefidelity