How to save mask to file

You would need to design the the process you want to use and code the script.  For example if I want to create a collage template that would looks like a pile of 4" x 6" images  were toss randomly on a table I may prototype that collage  Create a document the size I want the collage to be.  Create a 4x6 Layer and duplicate it x number if time where x is 53 or less.  The scatter layers over the canvas.  I would then runs  my script that  would convert the prototype collage into an actual template document.  Create Alpha channels for each image layer and merge all the layers into the background.  The problem is my Collage populating scripts do not support rotating image they place in.  That I have to do manually after the image are populated.  So  I would be more likely scatter some shape layer so place in images would have different shapes  I would not add rotation when I distribute the shape layers. The collaget will look like the dhaped image were carfully layer out one the canvas.

/* ==========================================================
// 2011  John J. McAssey (JJMack) 
// ======================================================= */
// This script is supplied as is. It is provided as freeware. 
// The author accepts no liability for any problems arising from its use.
/* Help Category note tag menu can be used to place script in automate menu
<javascriptresource>
<about>$$$/JavaScripts/LayerToAlphaChan./About=JJMack's Create Alpha Channels for layers placement then Flatten.^r^rCopyright 2011 Mouseprints.^r^rBuild a Photo Collage Toolkit type Template</about>
<category>JJMack's Collage Script</category>
</javascriptresource>
*/
// enable double-clicking from Mac Finder or Windows Explorer
#target photoshop // this command only works in Photoshop CS2 and higher
// bring application forward for double-click events
app.bringToFront();
// ensure at least one document open
if (!documents.length) alert('There are no documents open.', 'No Document');
else {
// declare Global variables
app.activeDocument.suspendHistory('LayerToAlphaChan','main()'); // at least one document exists proceed
}
///////////////////////////////////////////////////////////////////////////////
//                            main function                                  //
///////////////////////////////////////////////////////////////////////////////
function main() {
// declare local variables
var startDisplayDialogs = app.displayDialogs;
var orig_ruler_units = app.preferences.rulerUnits;
app.displayDialogs = DialogModes.NO;
app.preferences.rulerUnits = Units.PIXELS; // Set the ruler units to PIXELS
try { code(); }
// display error message if something goes wrong
catch(e) { alert(e + ': on line ' + e.line, 'Script Error', true); }
app.preferences.rulerUnits = orig_ruler_units; // Reset units to original settings
app.displayDialogs = startDisplayDialogs;
}
///////////////////////////////////////////////////////////////////////////////
//                           main function end                               //
///////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////
// The real code is embedded into this function so that at any point it can return //
// to the main line function to let it restore users edit environment and end      //
/////////////////////////////////////////////////////////////////////////////////////
function code() {
// Create Alpha Channels for Layers named Image 1 through Image n Then Flatten Image 
var layers = activeDocument.layers;
if ( layers.length < 2) {
alert("The current Document is Flat!");
return;
}
activeDocument.activeLayer = layers[layers.length-1] // Target Bottom Layer; 
var imageCount = layers.length -1; // number of layer over the bottom layer
if ( imageCount >= 54) { 
alert(imageCount + " images exceed the maximum allowed limit of 53"); 
return;
}
for (i=1; i<imageCount +1; i++) { // Create Image n Alpha Channels
layerForward();
if( activeDocument.activeLayer.kind == LayerKind.SMARTOBJECT)  {rasterizeLayer();}
if( activeDocument.activeLayer.kind == LayerKind.SOLIDFILL)  {rasterizeLayer();}
if( activeDocument.activeLayer.kind != LayerKind.NORMAL) {continue;}
selectTranparency(); 
saveAlpha("Image " + i);
}
activeDocument.selection.deselect(); // Deselect
activeDocument.flatten() // Flatten Template
makeLayer("Mat"); // Add Layer for mat
fillColor(); // Fill with light gray
addTexture(); // add texture
addStyle("Mat"); // add Mat Layer Style
selectChannelTrans("Image 1"); // Select Image locations
for (i=2; i<imageCount +1; i++) addChannelTrans("Image " + i);
try {
activeDocument.selection.clear(); // cut Mat for images
}
catch(e) {};
activeDocument.selection.deselect(); // deselect
addClipHueAdj(); // add a clipped hue and saturation adjustment layer
targetCont("Mat"); // Target layers continiously to Mat Layer
makeGroup("Mat"); // Make Mat Layer Group
hideGroup(); // Hide Group
SetViewFitonScreen()
}
//////////////////////////////////////////////////////////////////////////////////
// Helper Functions //
//////////////////////////////////////////////////////////////////////////////////
function layerForward(){
var idslct = charIDToTypeID( "slct" );
    var desc26 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref19 = new ActionReference();
         var idLyr = charIDToTypeID( "Lyr " );
         var idOrdn = charIDToTypeID( "Ordn" );
        var idFrwr = charIDToTypeID( "Frwr" );
        ref19.putEnumerated( idLyr, idOrdn, idFrwr );
     desc26.putReference( idnull, ref19 );
    var idMkVs = charIDToTypeID( "MkVs" );
    desc26.putBoolean( idMkVs, false );
executeAction( idslct, desc26, DialogModes.NO );
}
function selectTranparency(){
var idsetd = charIDToTypeID( "setd" );
    var desc26 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
         var ref9 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        var idfsel = charIDToTypeID( "fsel" );
        ref9.putProperty( idChnl, idfsel );
    desc26.putReference( idnull, ref9 );
    var idT = charIDToTypeID( "T   " );
        var ref10 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        var idChnl = charIDToTypeID( "Chnl" );
         var idTrsp = charIDToTypeID( "Trsp" );
        ref10.putEnumerated( idChnl, idChnl, idTrsp );
     desc26.putReference( idT, ref10 );
executeAction( idsetd, desc26, DialogModes.NO );
}
function  saveAlpha(alphaName){
var idDplc = charIDToTypeID( "Dplc" );
    var desc27 = new ActionDescriptor();
     var idnull = charIDToTypeID( "null" );
        var ref11 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        var idfsel = charIDToTypeID( "fsel" );
        ref11.putProperty( idChnl, idfsel );
    desc27.putReference( idnull, ref11 );
    var idNm = charIDToTypeID( "Nm  " );
    desc27.putString( idNm, alphaName );
try {
executeAction( idDplc, desc27, DialogModes.NO );
}
catch(e) {}
}
function makeLayer(name){
var idMk = charIDToTypeID( "Mk  " );
    var desc138 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref91 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        ref91.putClass( idLyr );
    desc138.putReference( idnull, ref91 );
    var idUsng = charIDToTypeID( "Usng" );
        var desc139 = new ActionDescriptor();
        var idNm = charIDToTypeID( "Nm  " );
        desc139.putString( idNm, name );
    var idLyr = charIDToTypeID( "Lyr " );
    desc138.putObject( idUsng, idLyr, desc139 );
executeAction( idMk, desc138, DialogModes.NO );
}
function selectChannelTrans(name){  
var idsetd = charIDToTypeID( "setd" );
    var desc22 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref20 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        var idfsel = charIDToTypeID( "fsel" );
         ref20.putProperty( idChnl, idfsel );
     desc22.putReference( idnull, ref20 );
    var idT = charIDToTypeID( "T   " );
        var ref21 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        ref21.putName( idChnl, name );
     desc22.putReference( idT, ref21 );
try {
executeAction( idsetd, desc22, DialogModes.NO );
}
catch(e) {};
}
function addChannelTrans(image) {
var idAdd = charIDToTypeID( "Add " );
    var desc23 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref22 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        ref22.putName( idChnl, image );
    desc23.putReference( idnull, ref22 );
    var idT = charIDToTypeID( "T   " );
        var ref23 = new ActionReference();
        var idChnl = charIDToTypeID( "Chnl" );
        var idfsel = charIDToTypeID( "fsel" );
        ref23.putProperty( idChnl, idfsel );
    desc23.putReference( idT, ref23 );
try {
executeAction( idAdd, desc23, DialogModes.NO );
}
catch(e) {};
}
function fillColor(){
// Hard coded Fill with light gray
var idFl = charIDToTypeID( "Fl  " );
    var desc31 = new ActionDescriptor();
    var idUsng = charIDToTypeID( "Usng" );
    var idFlCn = charIDToTypeID( "FlCn" );
    var idClr = charIDToTypeID( "Clr " );
    desc31.putEnumerated( idUsng, idFlCn, idClr );
    var idClr = charIDToTypeID( "Clr " );
        var desc32 = new ActionDescriptor();
         var idRd = charIDToTypeID( "Rd  " );
        desc32.putDouble( idRd, 221.996109 );
        var idGrn = charIDToTypeID( "Grn " );
        desc32.putDouble( idGrn, 221.996109 );
        var idBl = charIDToTypeID( "Bl  " );
        desc32.putDouble( idBl, 221.996109 );
    var idRGBC = charIDToTypeID( "RGBC" );
     desc31.putObject( idClr, idRGBC, desc32 );
     var idOpct = charIDToTypeID( "Opct" );
    var idPrc = charIDToTypeID( "#Prc" );
    desc31.putUnitDouble( idOpct, idPrc, 100.000000 );
    var idMd = charIDToTypeID( "Md  " );
    var idBlnM = charIDToTypeID( "BlnM" );
    var idNrml = charIDToTypeID( "Nrml" );
    desc31.putEnumerated( idMd, idBlnM, idNrml );
executeAction( idFl, desc31, DialogModes.NO );
}
function addTexture(){  
// texturizer sandstone
var idTxtz = charIDToTypeID( "Txtz" );
    var desc87 = new ActionDescriptor();
    var idGEfk = charIDToTypeID( "GEfk" );
    var idGEft = charIDToTypeID( "GEft" );
    var idTxtz = charIDToTypeID( "Txtz" );
    desc87.putEnumerated( idGEfk, idGEft, idTxtz );
    var idTxtT = charIDToTypeID( "TxtT" );
    var idTxtT = charIDToTypeID( "TxtT" );
    var idTxSt = charIDToTypeID( "TxSt" );
    desc87.putEnumerated( idTxtT, idTxtT, idTxSt );
    var idScln = charIDToTypeID( "Scln" );
    desc87.putInteger( idScln, 85 );
    var idRlf = charIDToTypeID( "Rlf " );
    desc87.putInteger( idRlf, 6 );
    var idLghD = charIDToTypeID( "LghD" );
    var idLghD = charIDToTypeID( "LghD" );
    var idLDTL = charIDToTypeID( "LDTL" );
    desc87.putEnumerated( idLghD, idLghD, idLDTL );
    var idInvT = charIDToTypeID( "InvT" );
    desc87.putBoolean( idInvT, false );
try{
executeAction( idTxtz, desc87, DialogModes.NO );
}catch(e){}
}
function addStyle(Style){
var idASty = charIDToTypeID( "ASty" );
    var desc20 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref3 = new ActionReference();
        var idStyl = charIDToTypeID( "Styl" );
        ref3.putName( idStyl, Style );
    desc20.putReference( idnull, ref3 );
    var idT = charIDToTypeID( "T   " );
        var ref4 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        var idOrdn = charIDToTypeID( "Ordn" );
        var idTrgt = charIDToTypeID( "Trgt" );
        ref4.putEnumerated( idLyr, idOrdn, idTrgt );
    desc20.putReference( idT, ref4 );
try{
executeAction( idASty, desc20, DialogModes.NO);
}catch(e){}
}
function addClipHueAdj(){ 
// Add a Clipped Hue and Saturation Adjustment layer
var idMk = charIDToTypeID( "Mk  " );
    var desc90 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref66 = new ActionReference();
        var idAdjL = charIDToTypeID( "AdjL" );
        ref66.putClass( idAdjL );
    desc90.putReference( idnull, ref66 );
    var idUsng = charIDToTypeID( "Usng" );
        var desc91 = new ActionDescriptor();
        var idGrup = charIDToTypeID( "Grup" );
        desc91.putBoolean( idGrup, true );
        var idType = charIDToTypeID( "Type" );
            var desc92 = new ActionDescriptor();
            var idpresetKind = stringIDToTypeID( "presetKind" );
            var idpresetKindType = stringIDToTypeID( "presetKindType" );
            var idpresetKindDefault = stringIDToTypeID( "presetKindDefault" );
            desc92.putEnumerated( idpresetKind, idpresetKindType, idpresetKindDefault );
            var idClrz = charIDToTypeID( "Clrz" );
            desc92.putBoolean( idClrz, false );
        var idHStr = charIDToTypeID( "HStr" );
        desc91.putObject( idType, idHStr, desc92 );
    var idAdjL = charIDToTypeID( "AdjL" );
    desc90.putObject( idUsng, idAdjL, desc91 );
executeAction( idMk, desc90, DialogModes.NO );
// Adjust hue adjustment layer
var idsetd = charIDToTypeID( "setd" );
    var desc182 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref106 = new ActionReference();
        var idAdjL = charIDToTypeID( "AdjL" );
        var idOrdn = charIDToTypeID( "Ordn" );
        var idTrgt = charIDToTypeID( "Trgt" );
        ref106.putEnumerated( idAdjL, idOrdn, idTrgt );
    desc182.putReference( idnull, ref106 );
    var idT = charIDToTypeID( "T   " );
        var desc183 = new ActionDescriptor();
        var idClrz = charIDToTypeID( "Clrz" );
        desc183.putBoolean( idClrz, true );
        var idAdjs = charIDToTypeID( "Adjs" );
            var list27 = new ActionList();
                var desc184 = new ActionDescriptor();
                var idChnl = charIDToTypeID( "Chnl" );
                var idChnl = charIDToTypeID( "Chnl" );
                var idCmps = charIDToTypeID( "Cmps" );
                desc184.putEnumerated( idChnl, idChnl, idCmps );
                var idH = charIDToTypeID( "H   " );
                desc184.putInteger( idH, 48 );
                var idStrt = charIDToTypeID( "Strt" );
                desc184.putInteger( idStrt, 78 );
                var idLght = charIDToTypeID( "Lght" );
                desc184.putInteger( idLght, 2 );
            var idHsttwo = charIDToTypeID( "Hst2" );
            list27.putObject( idHsttwo, desc184 );
        desc183.putList( idAdjs, list27 );
    var idHStr = charIDToTypeID( "HStr" );
    desc182.putObject( idT, idHStr, desc183 );
executeAction( idsetd, desc182, DialogModes.NO );
}
function targetCont(name){
var idslct = charIDToTypeID( "slct" );
    var desc96 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref68 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        ref68.putName( idLyr, name );
    desc96.putReference( idnull, ref68 );
    var idselectionModifier = stringIDToTypeID( "selectionModifier" );
    var idselectionModifierType = stringIDToTypeID( "selectionModifierType" );
    var idaddToSelectionContinuous = stringIDToTypeID( "addToSelectionContinuous" );
    desc96.putEnumerated( idselectionModifier, idselectionModifierType, idaddToSelectionContinuous );
    var idMkVs = charIDToTypeID( "MkVs" );
    desc96.putBoolean( idMkVs, false );
executeAction( idslct, desc96, DialogModes.NO );
}
function makeGroup(name){  
var idMk = charIDToTypeID( "Mk  " );
    var desc97 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref69 = new ActionReference();
        var idlayerSection = stringIDToTypeID( "layerSection" );
        ref69.putClass( idlayerSection );
    desc97.putReference( idnull, ref69 );
    var idFrom = charIDToTypeID( "From" );
        var ref70 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        var idOrdn = charIDToTypeID( "Ordn" );
        var idTrgt = charIDToTypeID( "Trgt" );
        ref70.putEnumerated( idLyr, idOrdn, idTrgt );
    desc97.putReference( idFrom, ref70 );
    var idUsng = charIDToTypeID( "Usng" );
        var desc98 = new ActionDescriptor();
        var idNm = charIDToTypeID( "Nm  " );
        desc98.putString( idNm, name );
    var idlayerSection = stringIDToTypeID( "layerSection" );
    desc97.putObject( idUsng, idlayerSection, desc98 );
executeAction( idMk, desc97, DialogModes.NO );
}
function hideGroup(){ 
var idHd = charIDToTypeID( "Hd  " );
    var desc118 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var list11 = new ActionList();
            var ref78 = new ActionReference();
            var idLyr = charIDToTypeID( "Lyr " );
            var idOrdn = charIDToTypeID( "Ordn" );
            var idTrgt = charIDToTypeID( "Trgt" );
            ref78.putEnumerated( idLyr, idOrdn, idTrgt );
        list11.putReference( ref78 );
    desc118.putList( idnull, list11 );
executeAction( idHd, desc118, DialogModes.NO );
}
//==================== Set View Fit on Screen ==============
function SetViewFitonScreen() {
// Menu View>screen Mode Standard
var desc1 = new ActionDescriptor();
var ref1 = new ActionReference();
ref1.putEnumerated(charIDToTypeID('Mn  '), charIDToTypeID('MnIt'), stringIDToTypeID("screenModeStandard"));
desc1.putReference(charIDToTypeID('null'), ref1);
executeAction(charIDToTypeID('slct'), desc1, DialogModes.NO);
// Menu View>Fit on screen
var desc1 = new ActionDescriptor();
var ref1 = new ActionReference();
ref1.putEnumerated(charIDToTypeID('Mn  '), charIDToTypeID('MnIt'), charIDToTypeID('FtOn'));
desc1.putReference(charIDToTypeID('null'), ref1);
executeAction(charIDToTypeID('slct'), desc1, DialogModes.NO);
};
// ================ rasterizeLayer =======================================
function rasterizeLayer() {
var idrasterizeLayer = stringIDToTypeID( "rasterizeLayer" );
var desc47 = new ActionDescriptor();
var idnull = charIDToTypeID( "null" );
var ref24 = new ActionReference();
var idLyr = charIDToTypeID( "Lyr " );
var idOrdn = charIDToTypeID( "Ordn" );
var idTrgt = charIDToTypeID( "Trgt" );
ref24.putEnumerated( idLyr, idOrdn, idTrgt );
desc47.putReference( idnull, ref24 );
executeAction( idrasterizeLayer, desc47, DialogModes.NO );
}