This might help...

http://www.scriptsrus.talktalk.net/Pdfprocessor.htm

Are the original pdfs proper vector-pdfs, are the texts actual searchable text?

Because then I would doubt the wisdom of converting them to pdfs than only contain pixel images.

Do you have Photoshop CS6?

Because PDF Presentation was reintroduced and therefore one could create multipage pdfs from Photoshop again.

By the way: You mentioned the pdfs have no searchable text, so I wonder if the individual odf-pages are actually images?

In that case converting the pages would seem less advisable than opening the images.

So do the pages originally contain vector/font elements or not?

That does not answer my question.

Does the original pdf consist of pages that contain vector data or is it actually a pdf that consists of only one image per page?

// 2012, use it at your own risk;

#target photoshop

// get folder;

var theFolder = Folder.selectDialog ("select folder");

if (theFolder) {

var theFiles = theFolder.getFiles(/\.(pdf)$/i);

if (theFiles.length > 0) {

// work through files;

for (var x = 0; x < theFiles.length; x++) {

var pdf = theFiles[x];

// create jpgs;

if(pdf != null){

var theseFiles = new Array;

var folderPath = pdf.fsName.slice(0, pdf.fsName.lastIndexOf("/"))+"/jpgs";

var theFolder = new Folder(folderPath);

if (theFolder.exists == false) {theFolder.create()};

for(var i =1; i<500; i++){

    var mode = OpenDocumentMode.RGB;

          rasterizePDF( i, 300, mode, pdf); //Page Number, Resolution, File

          if(app.documents.length == 0) break;    //loop passed the number of pages

// code to process page     

app.activeDocument.flatten();

app.activeDocument.activeLayer.duplicate();

app.activeDocument.activeLayer = app.activeDocument.artLayers.getByName('Background copy');

var idDfs = charIDToTypeID( "Dfs " );

var desc44 = new ActionDescriptor();

var idMd = charIDToTypeID( "Md  " );

var idDfsM = charIDToTypeID( "DfsM" );

var idanisotropic = stringIDToTypeID( "anisotropic" );

desc44.putEnumerated( idMd, idDfsM, idanisotropic );

var idFlRs = charIDToTypeID( "FlRs" );

desc44.putInteger( idFlRs, 4837760 );

executeAction( idDfs, desc44, DialogModes.NO );

app.activeDocument.activeLayer.applyUnSharpMask(50, 2.0, 0);

app.activeDocument.flatten();

if(app.documents.length > 0){

          var saveFile = new File(folderPath + "/" + pdf.name +"-Page" + i + ".jpg");

          SaveJPEG(saveFile,12);

          app.activeDocument.close(SaveOptions.DONOTSAVECHANGES);

          theseFiles.push(saveFile);

          };

};

// create the collection pdf;

pdfPresentation (theseFiles, String(pdf.fsName).replace(".pdf", "_jpg.pdf"))

}

}

}

};

////////////////////////////////////

function rasterizePDF( pageNumber,res, mode, pdfFile){//pageNumber as integer, pdfFile as File object

    var desc = new ActionDescriptor();

        var optionsDesc = new ActionDescriptor();

        optionsDesc.putString( charIDToTypeID( "Nm  " ), "rasterized page" );

        optionsDesc.putEnumerated( charIDToTypeID( "Crop" ), stringIDToTypeID( "cropTo" ), stringIDToTypeID( "trimBox" ) );

        optionsDesc.putUnitDouble( charIDToTypeID( "Rslt" ), charIDToTypeID( "#Rsl" ), res);

        optionsDesc.putEnumerated( charIDToTypeID( "Md  " ), charIDToTypeID( "ClrS" ), charIDToTypeID( "ERGB" ) );

        optionsDesc.putInteger( charIDToTypeID( "Dpth" ), 8 );

        optionsDesc.putBoolean( charIDToTypeID( "AntA" ), true );

        optionsDesc.putBoolean( stringIDToTypeID( "suppressWarnings" ), false );

        optionsDesc.putEnumerated( charIDToTypeID( "fsel" ), stringIDToTypeID( "pdfSelection" ), stringIDToTypeID( "page"  ));

        optionsDesc.putInteger( charIDToTypeID( "PgNm" ), pageNumber );

    desc.putObject( charIDToTypeID( "As  " ), charIDToTypeID( "PDFG" ), optionsDesc );

    desc.putPath( charIDToTypeID( "null" ), pdfFile );

executeAction( charIDToTypeID( "Opn " ), desc, DialogModes.NO );

};

function SaveJPEG(saveFile, jpegQuality){

jpgSaveOptions = new JPEGSaveOptions()

jpgSaveOptions.embedColorProfile = true

jpgSaveOptions.formatOptions = FormatOptions.STANDARDBASELINE

jpgSaveOptions.matte = MatteType.NONE

jpgSaveOptions.quality = jpegQuality //1-12

activeDocument.saveAs(saveFile, jpgSaveOptions, true,Extension.LOWERCASE)

};

////// function pdf presentation //////

function pdfPresentation (theFiles, thePath) {

// =======================================================

var idPDFExport = stringIDToTypeID( "PDFExport" );

    var desc1 = new ActionDescriptor();

    var idflst = charIDToTypeID( "flst" );

        var list1 = new ActionList();

for (var m = 0; m < theFiles.length; m++) {

        list1.putPath( new File( theFiles[m] ) );

//        list1.putPath( new File( "/Volumes/Backup HD/photoshop/test/illustratorMove.jpg" ) );

//        list1.putPath( new File( "/Volumes/Backup HD/photoshop/test/scripteventmanager.jpg" ) );

                    };

    desc1.putList( idflst, list1 );

    var idT = charIDToTypeID( "T   " );

    desc1.putPath( idT, new File( thePath ) );

    var idincludeAnnotations = stringIDToTypeID( "includeAnnotations" );

    desc1.putBoolean( idincludeAnnotations, true );

    var idBckC = charIDToTypeID( "BckC" );

    var idBckC = charIDToTypeID( "BckC" );

    var idWht = charIDToTypeID( "Wht " );

    desc1.putEnumerated( idBckC, idBckC, idWht );

    var idAs = charIDToTypeID( "As  " );

        var desc2 = new ActionDescriptor();

        var idpdfPresetFilename = stringIDToTypeID( "pdfPresetFilename" );

        desc2.putString( idpdfPresetFilename, """High Quality Print""" );

        var idpdfPreserveEditing = stringIDToTypeID( "pdfPreserveEditing" );

        desc2.putBoolean( idpdfPreserveEditing, false );

        var idpdfDownSample = stringIDToTypeID( "pdfDownSample" );

        var idpdfDownSample = stringIDToTypeID( "pdfDownSample" );

        var idNone = charIDToTypeID( "None" );

        desc2.putEnumerated( idpdfDownSample, idpdfDownSample, idNone );

        var idpdfCompressionType = stringIDToTypeID( "pdfCompressionType" );

        desc2.putInteger( idpdfCompressionType, 7 );

    var idPhtP = charIDToTypeID( "PhtP" );

    desc1.putObject( idAs, idPhtP, desc2 );

executeAction( idPDFExport, desc1, DialogModes.NO );

};