improved list_files_in_directory syntax

util/list_files_in_directory.m

@@ -2,10 +2,11 @@
 % Given a directory, list all files inside the directory and create a cell
 % array of strings, where each string is the file location
 %
-% extensions is optional and a cell array of extensions that you want this
-% function to return. If given, any file with an extension not listed in this
-% cell array will be not be returned. If extensions is true, then only images
-% will be returned.
+% extensions is optional and can take a variety of types:
+% - if it is a cell array, only return files with extensions in this array
+% - if it is the string 'images', only return images
+% - if it is a string, only return files with this extension
+% - if it is not given, return all files
 %
 % NOTE: this can be used with convert_to_I, as follows >> files =
 % list_files_in_directory('~/myimages/'); >> imagesc(convert_to_I(files{10}))
@@ -23,8 +24,14 @@
 files = cellfun2(@(x)[dirpath '/' x],files);
 
 if exist('extensions', 'var'),
-  if ~iscell(extensions),
-    extensions = {'.jpg', '.png', '.gif', '.ppm', '.tif', '.jpeg'};
+  if isstr(extensions),
+    if strcmpi(extensions, 'images') || strcmpi(extensions, 'image'),
+      extensions = {'.jpg', '.png', '.gif', '.ppm', '.tif', '.jpeg'};
+    elseif strcmpi(extensions, 'videos') || strcmpi(extensions, 'video'),
+      extensions = {'.mp4', '.mov', '.avi', '.ogv', '.wmv'};
+    else,
+      extensions = {extensions};
+    end
   end
   ext = cellfun2(@(x)get_extension(x), files);
   ext = cellfun2(@(x)any(strcmp(x, extensions)), ext);