activeDocument.bitsPerChannel = BitsPerChannelType.SIXTEEN; (WITHOUT MEREGER?) (Extendscript)

Question

I really hope the someone can help out. I just need to change depth from 32 to 16 bit without merging the layers. The code for changing depth is as follows:

activeDocument.bitsPerChannel = BitsPerChannelType.SIXTEEN;

However, it flattens the image (merges all layers).

I tried:

BitsPerChannelType.SIXTEEN.WITOUTMERGER;
BitsPerChannelType.SIXTEEN.WithoutMerger;

But it didn’t work. I can of course call an action from the script like I do to apply exposure adjustment layer app.doAction ("Exposure", "Processing");. But I want to know how.

Answer 1

To convert from 32 bit to 16 without merging use:

var idCnvM = charIDToTypeID( "CnvM" );
var desc27 = new ActionDescriptor();
var idDpth = charIDToTypeID( "Dpth" );
desc27.putInteger( idDpth, 16 );
var idMrge = charIDToTypeID( "Mrge" );
desc27.putBoolean( idMrge, false );
executeAction( idCnvM, desc27, DialogModes.NO );

Answer 2

Implemented:

function exeAction (Type, subType, Value) {

if (Type == 'Mode') {
    var desc27 = new ActionDescriptor();
    var idCnvM = charIDToTypeID ('CnvM');
    var idMrge = charIDToTypeID ('Mrge');
    desc27.putBoolean (idMrge, false);

        if (subType == 'Depth') {
            var idDpth = charIDToTypeID ('Dpth');
            desc27.putInteger (idDpth, Value);}
        else if (subType == 'Color') {}
    
    executeAction (idCnvM, desc27, DialogModes.NO);}
}

I tested and it works like a charm. I just need to add the rest of the IDcodes. I found this page Photoshop Scripting & Extension Reference which has become more useful than the Object Mode Viewer. I also found the Photoshop Javascript Ref 2020 however neither Dpth nor Mrge are listed under the Appendix A. Nevertheless, I also discovered the ScriptingListener plug-in.