Основен преглед
Colordesktoppublishingsystem,alsoknownasDTP,istheabbreviationofDeskTopPublishingbecauseitissmallandcanbeplacedNamedonthedesktop.
Thecolordesktoppublishingsystemisanewtypeofpre-pressprocessingequipmentintroducedinthe1990s.Itisacombinationofdesktopcolorseparationanddesktopelectronicpublishing.Itsadventfundamentallysolvesthedefectsofelectroniccolorseparationmachine'sweakabilitytoprocesstextandcannotmakenegativeorscientificnegativeswithintegratedgraphicsandtext.
Thecolordesktoppublishingsystemisdividedintothreeparts:input,processingandoutputfromtheoverallstructure.
Входно устройство
Thebasicfunctionoftheinputdeviceistoscan,separatecolorsandenterthesystem.Inadditiontotextinputandthecomputertypesettingsystemisthesame,imageinputcanuseavarietyofequipment,suchas:scanners,electroniccolorseparationmachines,cameras,plottersandsatellitegroundreceivingstations.Scannersaremorecommonlyused.
Therearetwotypesofscanners:platformtypeandrollertype.Thescannerusedincolordesktoppublishingsystemshouldhaveinputresolution,colornumberandscandensityrangesuitableforprintingrequirements.
(1)Входна резолюция
referstothenumberofpointssampledperinch,expressedindpi.Dpiandthenumberofdotlineslpihavethefollowingrelationship:
dpi(входна разделителна способност)=брой точкови линии×скорост на мащабиране×коефициент
Thecoefficientisgenerally1to2.Asthemagnificationincreases,therequiredresolutionincreases.Themagnificationofthereflectivemanuscriptissmall,calculatedat5times,1500dpiisenough.Theformatofthetransmissivemanuscriptissmall,anditiscalculatedat10times,and3000dpiwillwork.Somescannershavearesolutionof6000-8000dpi.Theactualresolutionuseddependsontheoutputresolutionandthezoomratiooftheimage.
(2)Цветни цифри и диапазон на сканиране
Цветните цифри се отнасят за това колко двоични цифри е представен определен цвят, като 8-битов, 16-битов, 24-битов, 36-битов и т.н.. Диапазонът на плътност на сканиране се отнася до разликата в плътността между най-светлите и най-тъмните части. Като цяло, колкото по-голям е диапазонът на плътност на сканиране, толкова повече цветни цифри. Ако диапазонът на плътност е по-голям от 3,0, са необходими поне 10 цифри.
Inaddition,thescannerisrequiredtoprovideastandarduniversaldataformat,accuratelyandreliablyacceptthecontroloftheworkstation,andhavethefunctionofautomaticenvironmentalcorrection,whichcancompensatefortheinterferenceoflightfromtheoutside,andatthesametime,ensurethatthescannercanreachUnderthepremiseofthemaintechnicalindicators,thefasterthescanningspeed,thebetter.
Оборудване за обработка
Оборудване за обработкаiscollectivelyreferredtoasgraphicworkstation.Thebasicfunctionistoprocessthemanuscriptdatathatentersthesystem,suchas:colorcorrection,revision,impositionandcreativeproduction,plustext,symbols,etc.,toformacompletepicture-textpage,andthensendittotheoutputdevice.
ThecomputeryouareusinghasaMaccamera(MAC)?PCsandworkstations,etc.Becausethehardwareequipmentandsoftwareavailablefordesktopsystemsareextremelyrich,whenselectinghardwareandsoftwaresuitableforprintingrequirementstoformasystem,severalissuessuchasprocessingspeed,processingcapacity,systemnetwork,andChineseenvironmentshouldbeconsidered.
(1) Скорост на обработка
Imageprocessingrequirespoint-by-pointprocessingofthepointsintheimage.Theamountofdataisverylargeandrequiresahighspeed.Ahigher-grademicrocomputershouldbeused.Orworkstation.
(2) Капацитет за обработка
Asimageprocessingrequireshigherandhigherinputresolutionandoutputresolution,thecapacityoftheworkstationtoprocessdataisincreasing.Atthesametime,itisalsorequiredtostorealargenumberofready-madeimagelibrariesandfontlibraries.
(3) Системна мрежа
Iftheworkofthecolordesktoppublishingsystemisnetworked,multiplecomputerswillworktogethertocompleteatask,andpeoplewillenjoyexpensivescanningandrecordingequipment.Therefore,itisnecessarytoselectareasonablesystemnetwork,networkserver,andfileservertosupportit.
(4) Китайска среда
Thedevelopmentofvariousforeignapplicationsoftwareisveryrapid,itisimpossibletoChineseizethenewapplicationsoftwareonebyoneandthenuseitinChina,whichrequiresgoodworkstationsWithitsChineseenvironmentandgoodcompatibilityandopenperformance,itcandirectlytransplantthenewlyopenedWesternlanguagesoftwaretothesystem'sChineseenvironmentwithoutanyproblems.
Изходно устройство
Theoutputdeviceisthedevicethatthecolordesktoppublishingsystemgeneratesthefinalproduct.Itismainlycomposedofahigh-precisionlaserimagesetter(alsocalledagraphicrecorder)andRIP(RasterImageProcessor).Thelaserimagesetterusesalasertogatherthebeamintoalightspot,hitthephotosensitivematerialtomakeitsensitive,anddevelopitintoablackandwhitenegative.RIPacceptsthelayoutofPostScriptlanguage,convertsitintoarasterimage,andthenoutputsitfromtheimagesetter.(PostScriptisapagedescriptionlanguagedevelopedbyAdobe.Itisnowacceptedbymanypeopleandhasbecomeastandard.)RIPcanbeimplementedbyhardwareorsoftware.ThehardwareRIPiscomposedofahigh-performancecomputerplusadedicatedchip.ThesoftwareRIPiscomposedofahigh-performancegeneral-purposemicrocomputerpluscorrespondingsoftware.Inordertomeettherequirementsofimageprocessingforprinting,theoutputresolution,outputrepeataccuracy,outputscreenstructure,outputspeedandotherperformanceindicatorsofthelaserimagesetterandRIPmustbeconsidered.
(1) Изходна разделителна способност
Разделителната способност на текста обикновено е 700～900 dpi, разделителната способност на изображението е 60 реда/cmdots, там разделителната способност изисква 2400 dpi, 70 реда/cm dots са необходими 3200 dpi.
(2) Повторяемост на изхода
Forhigh-endexquisiteprints,themaximumallowableerrorofrepeatabilityis5μm.Forgeneralprintedmattersuchasmanuals,booksandperiodicals,therepeataccuracyisallowedtobe20-25μm.Forlow-gradeprintedmattersuchascolornewspapers,theallowableerrorofrepeatabilityis25-50μm.
(3) Структура за скрининг на изхода
Itcanoutputdifferentdotlinesanddotshapes.Inordertoensurethatthecolorimageiscopiedwithoutobvioustortoiseordensityfluctuations,theoutputdeviceisrequiredtoproducedotswithgoodprintingperformance.
(4) Изходна скорост
TheoutputspeeddependsontheperformanceofRIPandgraphicrecorder.ThehardwareRIPspeedisfast,andthesoftwareRIPspeedisslow.Underthepremiseofoutputtingthesamequalitycolorseparationfilm,thefasterthebetter.
Inaddition,theoutputdeviceshouldalsohaveastandardinterfaceandtheabilitytooutputChinesecharacters,andtheoutputformatcanmeettherequirementsofprinting.
Theoutputdevicesofthecolordesktoppublishingsystemalsoincludevariouscolorprinterssuchaslaserprinters,inkjetprinters,thermalprinters,andvariousmultimediacarriers(slideshowmaker,CD-ROM,videorecorder,etc.).
Мрежа от висок клас
Thecolordesktoppublishingsystemisconnectedwithvarioustypesofexistingelectroniccolorseparationmachines,calledhigh-endnetworking,whichisanotherwayofworkingfordesktopsystems.
Whenusinghigh-endnetworkingtoobtainhigh-qualitygraphicnegatives,theelectroniccolorseparationmachineinterfacemustsolvetwokeyproblems.First,thespeedissue.Sincetheelectroniccolorseparationmachinecannotbecontrolledwhenitisinandinthestate,theinterfaceandtheinterfaceworkstationmustbefastenoughtoreceivethescanningdataoftheelectroniccolorseparationmachineandsenddatatotheelectroniccolorseparationmachineatthesametime.Second,thewaytooutputnegativesinoneimageandtext.Ifthedotgeneratoroftheelectroniccolorseparationmachineisusedtogeneratedots,onlyahigh-resolutioninterfaceisaddedtojointlycompletetheoutputoftheimageandtext.Ifyoudonotusethedotgeneratoroftheelectroniccolorseparationmachinetogeneratedots,andonlytreattherecordingpartoftheelectroniccolorseparationmachineasanimagetypesettingmachine,youneedtoaddaRIPtoprocessthedotsandtext,andthedesktopsystemusestheelectroniccolorseparationmachinethroughRIP.
Мрежа от висок класhasformedafull-pageimpositionsystemwithageneral-purposecomputerasthecore.Itnotonlytakesadvantageofthehighinputresolutionoftheelectroniccolorseparationmachineandgoodimageprocessingquality,butalsointegratestheadvantagesofthedesktopsystemthatcanprocessgraphicsandtextatthesametime.Itopensupanexcellentwayformanufacturerswithelectroniccolorseparationmachinestoimprovetheabilityandefficiencyofcolorplatemaking.