Script for splitting multiple PSDs to defined slices

The following script can be recorded into a single step action, then the action can be used with the batch command.

Change the following as required to suit your desired column/rows layout (it does not use slices or guides):

var theX = 4;
var theY = 2;

https://community.adobe.com/t5/photoshop-ecosystem-discussions/slicing-a-very-image-24k-px-x-34k-px-into-smaller-crops/m-p/9366573

/* https://community.adobe.com/t5/photoshop-ecosystem-discussions/slicing-a-very-image-24k-px-x-34k-px-into-smaller-crops/m-p/9366573#M115021 */

// split image into x times y segments and save them as jpgs;
// 2017, use it at your own risk;
#target photoshop
if (app.documents.length > 0) {
var originalUnits = app.preferences.rulerUnits;
app.preferences.rulerUnits = Units.PIXELS;
// document;
var myDocument = app.activeDocument;
var theName= myDocument.name.match(/(.*)\.[^\.]+$/)[1];
var thePath = myDocument.path;
var theCopy = myDocument.duplicate("copy", true);
// the numbers;
var theX = 4;
var theY = 2;
var xFrac = myDocument.width/theX;
var yFrac = myDocument.height/theY;
// psd options;
psdOpts = new PhotoshopSaveOptions();
psdOpts.embedColorProfile = true;
psdOpts.alphaChannels = true;
psdOpts.layers = true;
psdOpts.spotColors = true;
// jpg options;
var jpegOptions = new JPEGSaveOptions();
jpegOptions.quality = 9;
jpegOptions.embedColorProfile = true;
jpegOptions.matte = MatteType.NONE;
// create folder;
var folderName = thePath+"/"+theName+"_"+theX+"x"+theY;
if (Folder(folderName).exists == false) {Folder(folderName).create()};
//save jpgs;
for (var n = 1; n <= theY; n++) {
for (var m = 1; m <= theX; m++) {
cropTo((m-1)*xFrac, (n-1)*yFrac, m*xFrac, n*yFrac);
var theNewName = theName+"_"+bufferNumberWithZeros(m, 3)+"_"+bufferNumberWithZeros(n, 3);
theCopy.saveAs((new File(folderName+"/"+"_"+theNewName+".jpg")),jpegOptions,true);
theCopy.activeHistoryState = theCopy.historyStates[0];
//executeAction( charIDToTypeID("undo"), undefined, DialogModes.NO );
}
};
theCopy.close(SaveOptions.DONOTSAVECHANGES);
// reset;
app.preferences.rulerUnits = originalUnits;
};
////// buffer number with zeros //////
function bufferNumberWithZeros (number, places) {
var theNumberString = String(number);
for (var o = 0; o < (places - String(number).length); o++) {
theNumberString = String("0" + theNumberString)
};
return theNumberString
};
////// crop //////
function cropTo (x1, y1, x2, y2) {
// =======================================================
    var desc7 = new ActionDescriptor();
        var desc8 = new ActionDescriptor();
        var idPxl = charIDToTypeID( "#Pxl" );
        desc8.putUnitDouble( charIDToTypeID( "Top " ), idPxl, y1 );
        desc8.putUnitDouble( charIDToTypeID( "Left" ), idPxl, x1);
        desc8.putUnitDouble( charIDToTypeID( "Btom" ), idPxl, y2 );
        desc8.putUnitDouble( charIDToTypeID( "Rght" ), idPxl, x2 );
    var idRctn = charIDToTypeID( "Rctn" );
    desc7.putObject( charIDToTypeID( "T   " ), idRctn, desc8 );
    desc7.putUnitDouble( charIDToTypeID( "Angl" ), charIDToTypeID( "#Ang" ), 0.000000 );
    desc7.putBoolean( charIDToTypeID( "Dlt " ), false );
    desc7.putEnumerated( stringIDToTypeID( "cropAspectRatioModeKey" ), stringIDToTypeID( "cropAspectRatioModeClass" ), stringIDToTypeID( "pureAspectRatio" ) );
    desc7.putBoolean( charIDToTypeID( "CnsP" ), false );
executeAction( charIDToTypeID( "Crop" ), desc7, DialogModes.NO );
};

Code taken from this topic:

https://community.adobe.com/t5/photoshop-ecosystem-discussions/slicing-a-very-image-24k-px-x-34k-px-into-smaller-crops/m-p/9366573

Different code that does the same thing:

https://www.andrewnoske.com/wiki/Adobe_Photoshop_-_Scripts_Related_to_Montaging

Another topic with related info using slices or guides to layers (not files):

https://community.adobe.com/t5/photoshop-ecosystem-discussions/divide-my-image-to-layers/m-p/12467039

Instructions for saving/installing code:

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

Slices would appear to be unnecessary as this is just a case of two crops via canvas size adjustment.

Retrieve all slice information via script