batch background subtract problems

[Ninja Chris]

Hi,

I've adapted the batch folder process macro to perform background subtraction on all images in a folder but, being something of an amateur at this game, I'm having problems getting it to work.


// This macro subtracts a background image from each TIFF in a folder
   requires("1.33s");
   sdir = getDirectory("select source directory");
   final = "final"+File.separator;
   ddir = sdir+final;
   File.makeDirectory(ddir);
                background = File.openDialog("select background image for subtraction");
                open(background);
                background = getImageID();
   setBatchMode(true);
   count = 0;
   countFiles(sdir);
   n = 0;
   processFiles(sdir);
   //print(count+" files processed");
   
   function countFiles(sdir) {
      list = getFileList(sdir);
      for (i=0; i<list.length; i++) {
          if (endsWith(list[i], "/"))
              countFiles(""+sdir+list[i]);
          else
              count++;
      }
  }

   function processFiles(sdir) {
      list = getFileList(sdir);
      for (i=0; i<list.length; i++) {
          if (endsWith(list[i], "/"))
              processFiles(""+sdir+list[i]);
          else {
             showProgress(n++, count);
             path = sdir+list[i];
             processFile(path);
          }
      }
  }

  function processFile(path) {
       if (endsWith(path, ".tif")) {
        open(path);
                target = getImageID();
                imageCalculator("Difference create", target, background);
                result = getImageID();
                selectImage(target);
                close();
                selectImage(result);
        saveAs("tiff", ddir+list[i]);
        close();
      }
  }


The macro seems to conduct the subtraction and saves all the image files to the new folder "\final" but then overwrites them with the original images and I can't work out why!

Help plz?

Thanks,
Chris