Script to Make Brush Preset from PNG File

Try this script:

#target photoshop
var bName = prompt ('Enter a name for the brush', 'brush 1', 'Create Brush')
if(bName != null){
    var idMk = charIDToTypeID( "Mk  " );
        var desc5 = new ActionDescriptor();
        var idnull = charIDToTypeID( "null" );
            var ref1 = new ActionReference();
            var idBrsh = charIDToTypeID( "Brsh" );
            ref1.putClass( idBrsh );
        desc5.putReference( idnull, ref1 );
        var idUsng = charIDToTypeID( "Usng" );
            var ref2 = new ActionReference();
            var idPrpr = charIDToTypeID( "Prpr" );
            var idfsel = charIDToTypeID( "fsel" );
            ref2.putProperty( idPrpr, idfsel );
            var idDcmn = charIDToTypeID( "Dcmn" );
            var idOrdn = charIDToTypeID( "Ordn" );
            var idTrgt = charIDToTypeID( "Trgt" );
            ref2.putEnumerated( idDcmn, idOrdn, idTrgt );
        desc5.putReference( idUsng, ref2 );
        var idNm = charIDToTypeID( "Nm  " );
        desc5.putString( idNm, bName );
    executeAction( idMk, desc5, DialogModes.NO );
    }