如何用PS批量处理多张图片？

// 示例：记录一个简单的Action
app.bringToFront();
var idMk = charIDToTypeID( "Mk  " );
    var desc1 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref1 = new ActionReference();
        var idActn = charIDToTypeID( "Actn" );
        ref1.putClass( idActn );
    desc1.putReference( idnull, ref1 );
    var idNm = charIDToTypeID( "Nm  " );
    desc1.putString( idNm, "MyAction" );
    var idUsng = charIDToTypeID( "Usng" );
        var ref2 = new ActionReference();
        var idASet = charIDToTypeID( "ASet" );
        ref2.putName( idASet, "Default Actions" );
    desc1.putReference( idUsng, ref2 );
executeAction( idMk, desc1, DialogModes.NO );

// 示例：Batch处理多张图片
var folder = Folder.selectDialog("选择包含图片的文件夹");
if (folder != null) {
    var files = folder.getFiles(/\.(jpg|jpeg|png|gif)$/i);
    for (var i = 0; i < files.length; i++) {
        var file = files[i];
        app.open(file);
        app.doAction("MyAction", "Default Actions");
        var saveFile = new File(file.path + "/" + file.name.split('.')[0] + "_processed.jpg");
        var saveOptions = new JPEGSaveOptions();
        saveOptions.quality = 12;
        activeDocument.saveAs(saveFile, saveOptions, true, Extension.LOWERCASE);
        activeDocument.close(SaveOptions.DONOTSAVECHANGES);
    }
}