Základní přehled
Colordesktoppublishingsystem,alsoknownasDTP,istheabbreviationofDeskTopPublishingbecauseitissmallandcanbeplacedNamedonthedesktop.
Thecolordesktoppublishingsystemisanewtypeofpre-pressprocessingequipmentintroducedinthe1990s.Itisacombinationofdesktopcolorseparationanddesktopelectronicpublishing.Itsadventfundamentallysolvesthedefectsofelectroniccolorseparationmachine'sweakabilitytoprocesstextandcannotmakenegativeorscientificnegativeswithintegratedgraphicsandtext.
Thecolordesktoppublishingsystemisdividedintothreeparts:input,processingandoutputfromtheoverallstructure.
Vstupní zařízení
Thebasicfunctionoftheinputdeviceistoscan,separatecolorsandenterthesystem.Inadditiontotextinputandthecomputertypesettingsystemisthesame,imageinputcanuseavarietyofequipment,suchas:scanners,electroniccolorseparationmachines,cameras,plottersandsatellitegroundreceivingstations.Scannersaremorecommonlyused.
Therearetwotypesofscanners:platformtypeandrollertype.Thescannerusedincolordesktoppublishingsystemshouldhaveinputresolution,colornumberandscandensityrangesuitableforprintingrequirements.
(1)Vstupní rozlišení
referstothenumberofpointssampledperinch,expressedindpi.Dpiandthenumberofdotlineslpihavethefollowingrelationship:
dpi(vstupní rozlišení)=počet tečkovaných řádků × rychlost přiblížení × koeficient
Thecoefficientisgenerally1to2.Asthemagnificationincreases,therequiredresolutionincreases.Themagnificationofthereflectivemanuscriptissmall,calculatedat5times,1500dpiisenough.Theformatofthetransmissivemanuscriptissmall,anditiscalculatedat10times,and3000dpiwillwork.Somescannershavearesolutionof6000-8000dpi.Theactualresolutionuseddependsontheoutputresolutionandthezoomratiooftheimage.
(2)Rozsah barevných číslic a skenování
Barevné číslice odkazují na to, kolik binárních číslic je zastoupena určitá barva, například 8bitové, 16bitové, 24bitové, 36bitové atd..Rozsah hustoty skenování se týká rozdílu hustoty mezi nejsvětlejšími a nejtmavšími částmi.
Inaddition,thescannerisrequiredtoprovideastandarduniversaldataformat,accuratelyandreliablyacceptthecontroloftheworkstation,andhavethefunctionofautomaticenvironmentalcorrection,whichcancompensatefortheinterferenceoflightfromtheoutside,andatthesametime,ensurethatthescannercanreachUnderthepremiseofthemaintechnicalindicators,thefasterthescanningspeed,thebetter.
Zpracovatelské vybavení
Zpracovatelské vybaveníiscollectivelyreferredtoasgraphicworkstation.Thebasicfunctionistoprocessthemanuscriptdatathatentersthesystem,suchas:colorcorrection,revision,impositionandcreativeproduction,plustext,symbols,etc.,toformacompletepicture-textpage,andthensendittotheoutputdevice.
ThecomputeryouareusinghasaMaccamera(MAC)?PCsandworkstations,etc.Becausethehardwareequipmentandsoftwareavailablefordesktopsystemsareextremelyrich,whenselectinghardwareandsoftwaresuitableforprintingrequirementstoformasystem,severalissuessuchasprocessingspeed,processingcapacity,systemnetwork,andChineseenvironmentshouldbeconsidered.
(1) Rychlost zpracování
Imageprocessingrequirespoint-by-pointprocessingofthepointsintheimage.Theamountofdataisverylargeandrequiresahighspeed.Ahigher-grademicrocomputershouldbeused.Orworkstation.
(2) Kapacita zpracování
Asimageprocessingrequireshigherandhigherinputresolutionandoutputresolution,thecapacityoftheworkstationtoprocessdataisincreasing.Atthesametime,itisalsorequiredtostorealargenumberofready-madeimagelibrariesandfontlibraries.
(3)Systémová síť
Iftheworkofthecolordesktoppublishingsystemisnetworked,multiplecomputerswillworktogethertocompleteatask,andpeoplewillenjoyexpensivescanningandrecordingequipment.Therefore,itisnecessarytoselectareasonablesystemnetwork,networkserver,andfileservertosupportit.
(4)Čínské prostředí
Thedevelopmentofvariousforeignapplicationsoftwareisveryrapid,itisimpossibletoChineseizethenewapplicationsoftwareonebyoneandthenuseitinChina,whichrequiresgoodworkstationsWithitsChineseenvironmentandgoodcompatibilityandopenperformance,itcandirectlytransplantthenewlyopenedWesternlanguagesoftwaretothesystem'sChineseenvironmentwithoutanyproblems.
Výstupní zařízení
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) Výstupní rozlišení
Rozlišení textu je obecně 700 až 900 dpi, rozlišení je 60 řádků/cmbodů, rozlišení vyžaduje 2400 dpi, 70 řádků/cmbodů je vyžadováno 3200 dpi.
(2)Opakovatelnost výstupu
Forhigh-endexquisiteprints,themaximumallowableerrorofrepeatabilityis5μm.Forgeneralprintedmattersuchasmanuals,booksandperiodicals,therepeataccuracyisallowedtobe20-25μm.Forlow-gradeprintedmattersuchascolornewspapers,theallowableerrorofrepeatabilityis25-50μm.
(3)OutputScreeningStructure
Itcanoutputdifferentdotlinesanddotshapes.Inordertoensurethatthecolorimageiscopiedwithoutobvioustortoiseordensityfluctuations,theoutputdeviceisrequiredtoproducedotswithgoodprintingperformance.
(4) Výstupní rychlost
TheoutputspeeddependsontheperformanceofRIPandgraphicrecorder.ThehardwareRIPspeedisfast,andthesoftwareRIPspeedisslow.Underthepremiseofoutputtingthesamequalitycolorseparationfilm,thefasterthebetter.
Inaddition,theoutputdeviceshouldalsohaveastandardinterfaceandtheabilitytooutputChinesecharacters,andtheoutputformatcanmeettherequirementsofprinting.
Theoutputdevicesofthecolordesktoppublishingsystemalsoincludevariouscolorprinterssuchaslaserprinters,inkjetprinters,thermalprinters,andvariousmultimediacarriers(slideshowmaker,CD-ROM,videorecorder,etc.).
Špičkové sítě
Thecolordesktoppublishingsystemisconnectedwithvarioustypesofexistingelectroniccolorseparationmachines,calledhigh-endnetworking,whichisanotherwayofworkingfordesktopsystems.
Whenusinghigh-endnetworkingtoobtainhigh-qualitygraphicnegatives,theelectroniccolorseparationmachineinterfacemustsolvetwokeyproblems.First,thespeedissue.Sincetheelectroniccolorseparationmachinecannotbecontrolledwhenitisinandinthestate,theinterfaceandtheinterfaceworkstationmustbefastenoughtoreceivethescanningdataoftheelectroniccolorseparationmachineandsenddatatotheelectroniccolorseparationmachineatthesametime.Second,thewaytooutputnegativesinoneimageandtext.Ifthedotgeneratoroftheelectroniccolorseparationmachineisusedtogeneratedots,onlyahigh-resolutioninterfaceisaddedtojointlycompletetheoutputoftheimageandtext.Ifyoudonotusethedotgeneratoroftheelectroniccolorseparationmachinetogeneratedots,andonlytreattherecordingpartoftheelectroniccolorseparationmachineasanimagetypesettingmachine,youneedtoaddaRIPtoprocessthedotsandtext,andthedesktopsystemusestheelectroniccolorseparationmachinethroughRIP.
Špičkové sítěhasformedafull-pageimpositionsystemwithageneral-purposecomputerasthecore.Itnotonlytakesadvantageofthehighinputresolutionoftheelectroniccolorseparationmachineandgoodimageprocessingquality,butalsointegratestheadvantagesofthedesktopsystemthatcanprocessgraphicsandtextatthesametime.Itopensupanexcellentwayformanufacturerswithelectroniccolorseparationmachinestoimprovetheabilityandefficiencyofcolorplatemaking.