http://imagej.273.s1.nabble.com/Apply-Substract-background-to-all-files-in-subfolders-tp3705174p3705187.html
>
> > It stops when it finds a file which is not an image in a
> > subdirectory and displays an appropriate error message
> > (I have some ZIP files in subdirectories).
> > Can I modify the macro in order to just let it handle .tiff and
> > .tif files for example?
>
> You can modify the macro at
> "
http://rsb.info.nih.gov/ij/macros/BatchProcessFolders.txt" to handle
> only .tif files by modifying the processFile() function as follows:
>
> function processFile(path) {
> if (endsWith(path, ".tif")) {
> open(path);
> run("Subtract Background...", "rolling=50 white");
> save(path);
> close();
> }
> }
>
> The save() function appears to not work with files that have a ".tiff"
> extension. You can use saveAs("tiff", path) but it changes the
> extension from ".tiff" to ".tif".
>
> -wayne
>