Color Desktop Publishing System

Basicoverview

Colordesktoppublishingsystem,alsoknownasDTP,istheabbreviationofDeskTopPublishingbecauseitissmallandcanbeplacedNamedonthedesktop.

Thecolordesktoppublishingsystemisanewtypeofpre-pressprocessingequipmentintroducedinthe1990s.Itisacombinationofdesktopcolorseparationanddesktopelectronicpublishing.Itsadventfundamentallysolvesthedefectsofelectroniccolorseparationmachine'sweakabilitytoprocesstextandcannotmakenegativeorscientificnegativeswithintegratedgraphicsandtext.

Thecolordesktoppublishingsystemisdividedintothreeparts:input,processingandoutputfromtheoverallstructure.

Inputdevice

Thebasicfunctionoftheinputdeviceistoscan,separatecolorsandenterthesystem.Inadditiontotextinputandthecomputertypesettingsystemisthesame,imageinputcanuseavarietyofequipment,suchas:scanners,electroniccolorseparationmachines,cameras,plottersandsatellitegroundreceivingstations.Scannersaremorecommonlyused.

Therearetwotypesofscanners:platformtypeandrollertype.Thescannerusedincolordesktoppublishingsystemshouldhaveinputresolution,colornumberandscandensityrangesuitableforprintingrequirements.

(1)Inputresolution

referstothenumberofpointssampledperinch,expressedindpi.Dpiandthenumberofdotlineslpihavethefollowingrelationship:

dpi(inputresolution)=numberofdotlines×zoomrate×coefficient

Thecoefficientisgenerally1to2.Asthemagnificationincreases,therequiredresolutionincreases.Themagnificationofthereflectivemanuscriptissmall,calculatedat5times,1500dpiisenough.Theformatofthetransmissivemanuscriptissmall,anditiscalculatedat10times,and3000dpiwillwork.Somescannershavearesolutionof6000-8000dpi.Theactualresolutionuseddependsontheoutputresolutionandthezoomratiooftheimage.

(2)Colordigitsandscandensityrange

Colordigitsrefertohowmanybinarydigitsacertaincolorisrepresented,suchas8-bit,16-bit,24-bit,36-bit,etc..Thescandensityrangereferstothedensitydifferencebetweenthelightestanddarkestparts.Generally,thelargerthescanningdensityrange,themorecolordigits.Ifthedensityrangeisgreaterthan3.0,atleast10digitsarerequired.

Inaddition,thescannerisrequiredtoprovideastandarduniversaldataformat,accuratelyandreliablyacceptthecontroloftheworkstation,andhavethefunctionofautomaticenvironmentalcorrection,whichcancompensatefortheinterferenceoflightfromtheoutside,andatthesametime,ensurethatthescannercanreachUnderthepremiseofthemaintechnicalindicators,thefasterthescanningspeed,thebetter.

Processingequipment

Processingequipmentiscollectivelyreferredtoasgraphicworkstation.Thebasicfunctionistoprocessthemanuscriptdatathatentersthesystem,suchas:colorcorrection,revision,impositionandcreativeproduction,plustext,symbols,etc.,toformacompletepicture-textpage,andthensendittotheoutputdevice.

ThecomputeryouareusinghasaMaccamera(MAC)?PCsandworkstations,etc.Becausethehardwareequipmentandsoftwareavailablefordesktopsystemsareextremelyrich,whenselectinghardwareandsoftwaresuitableforprintingrequirementstoformasystem,severalissuessuchasprocessingspeed,processingcapacity,systemnetwork,andChineseenvironmentshouldbeconsidered.

(1)Processingspeed

Imageprocessingrequirespoint-by-pointprocessingofthepointsintheimage.Theamountofdataisverylargeandrequiresahighspeed.Ahigher-grademicrocomputershouldbeused.Orworkstation.

(2)Processingcapacity

Asimageprocessingrequireshigherandhigherinputresolutionandoutputresolution,thecapacityoftheworkstationtoprocessdataisincreasing.Atthesametime,itisalsorequiredtostorealargenumberofready-madeimagelibrariesandfontlibraries.

(3)Systemnetwork

Iftheworkofthecolordesktoppublishingsystemisnetworked,multiplecomputerswillworktogethertocompleteatask,andpeoplewillenjoyexpensivescanningandrecordingequipment.Therefore,itisnecessarytoselectareasonablesystemnetwork,networkserver,andfileservertosupportit.

(4)Chineseenvironment

Thedevelopmentofvariousforeignapplicationsoftwareisveryrapid,itisimpossibletoChineseizethenewapplicationsoftwareonebyoneandthenuseitinChina,whichrequiresgoodworkstationsWithitsChineseenvironmentandgoodcompatibilityandopenperformance,itcandirectlytransplantthenewlyopenedWesternlanguagesoftwaretothesystem'sChineseenvironmentwithoutanyproblems.

Outputdevice

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)Outputresolution

Thetextresolutionisgenerally700~900dpi,theimageresolutionis60lines/cmdots,theresolutionrequires2400dpi,70lines/cmdots3200dpiisrequired.

(2)Outputrepeatability

Forhigh-endexquisiteprints,themaximumallowableerrorofrepeatabilityis5μm.Forgeneralprintedmattersuchasmanuals,booksandperiodicals,therepeataccuracyisallowedtobe20-25μm.Forlow-gradeprintedmattersuchascolornewspapers,theallowableerrorofrepeatabilityis25-50μm.

(3)OutputScreeningStructure

Itcanoutputdifferentdotlinesanddotshapes.Inordertoensurethatthecolorimageiscopiedwithoutobvioustortoiseordensityfluctuations,theoutputdeviceisrequiredtoproducedotswithgoodprintingperformance.

(4)Outputspeed

TheoutputspeeddependsontheperformanceofRIPandgraphicrecorder.ThehardwareRIPspeedisfast,andthesoftwareRIPspeedisslow.Underthepremiseofoutputtingthesamequalitycolorseparationfilm,thefasterthebetter.

Inaddition,theoutputdeviceshouldalsohaveastandardinterfaceandtheabilitytooutputChinesecharacters,andtheoutputformatcanmeettherequirementsofprinting.

Theoutputdevicesofthecolordesktoppublishingsystemalsoincludevariouscolorprinterssuchaslaserprinters,inkjetprinters,thermalprinters,andvariousmultimediacarriers(slideshowmaker,CD-ROM,videorecorder,etc.).

High-endnetworking

Thecolordesktoppublishingsystemisconnectedwithvarioustypesofexistingelectroniccolorseparationmachines,calledhigh-endnetworking,whichisanotherwayofworkingfordesktopsystems.

Whenusinghigh-endnetworkingtoobtainhigh-qualitygraphicnegatives,theelectroniccolorseparationmachineinterfacemustsolvetwokeyproblems.First,thespeedissue.Sincetheelectroniccolorseparationmachinecannotbecontrolledwhenitisinandinthestate,theinterfaceandtheinterfaceworkstationmustbefastenoughtoreceivethescanningdataoftheelectroniccolorseparationmachineandsenddatatotheelectroniccolorseparationmachineatthesametime.Second,thewaytooutputnegativesinoneimageandtext.Ifthedotgeneratoroftheelectroniccolorseparationmachineisusedtogeneratedots,onlyahigh-resolutioninterfaceisaddedtojointlycompletetheoutputoftheimageandtext.Ifyoudonotusethedotgeneratoroftheelectroniccolorseparationmachinetogeneratedots,andonlytreattherecordingpartoftheelectroniccolorseparationmachineasanimagetypesettingmachine,youneedtoaddaRIPtoprocessthedotsandtext,andthedesktopsystemusestheelectroniccolorseparationmachinethroughRIP.

High-endnetworkinghasformedafull-pageimpositionsystemwithageneral-purposecomputerasthecore.Itnotonlytakesadvantageofthehighinputresolutionoftheelectroniccolorseparationmachineandgoodimageprocessingquality,butalsointegratestheadvantagesofthedesktopsystemthatcanprocessgraphicsandtextatthesametime.Itopensupanexcellentwayformanufacturerswithelectroniccolorseparationmachinestoimprovetheabilityandefficiencyofcolorplatemaking.

Picturedisplay

Related Articles
TOP