app.bringToFront();

var rootFolder = Folder.selectDialog("Select a folder of documents to process");
var saveFolder = Folder.selectDialog("Select save folder");

rootFolder.changePath("./left");
var leftFileList = rootFolder.getFiles();
rootFolder.changePath("../right");
var rightFileList = rootFolder.getFiles();

var leftImage;
var rightImage;
var allChannels;

for (var i = 0; i < leftFileList.length; i++) {
	if ( leftFileList[i] instanceof File && ! leftFileList[i].hidden && IsFileATIF(leftFileList[i])) {
		leftImage = open(leftFileList[i]);
		leftImage.changeMode(ChangeMode.GRAYSCALE);
		leftImage.changeMode(ChangeMode.RGB);
		var activeChannels = new Array();
		allChannels = leftImage.activeChannels;
		for(var ci = 0; ci < leftImage.activeChannels.length; ci++) {
			if (leftImage.activeChannels[ci].name == "Red") {
				continue;
			} else {
				activeChannels.push(leftImage.activeChannels[ci]);
			}
		}
				
		leftImage.activeChannels = activeChannels;
	}
	if ( rightFileList[i] instanceof File && ! rightFileList[i].hidden && IsFileATIF(rightFileList[i])) {
		rightImage = open(rightFileList[i]);
		rightImage.changeMode(ChangeMode.GRAYSCALE);
		rightImage.selection.selectAll();
		rightImage.selection.copy();
		rightImage.close(SaveOptions.DONOTSAVECHANGES);
		leftImage.paste();
		leftImage.activeChannels = allChannels;
		outFile = new File(saveFolder + "/" + i.toString() + ".psd");
		saveOptions = new PhotoshopSaveOptions();
		leftImage.saveAs (outFile, saveOptions, true, Extension.LOWERCASE);
		leftImage.close(SaveOptions.DONOTSAVECHANGES);
	}
}




function IsFileATIF( inFileName ) {
	var lastDot = inFileName.toString().lastIndexOf( "." );
	if ( lastDot == -1 ) {
		return false;
	}
	var strLength = inFileName.toString().length;
	var extension = inFileName.toString().substr( lastDot + 1, strLength - lastDot );
	extension = extension.toLowerCase();
	if ( extension == "tif") {
		return true;
	}
	return false;
}