diff --git a/src/main/java/net/sf/javaanpr/gui/tools/ImageFileFilter.java b/src/main/java/net/sf/javaanpr/gui/tools/ImageFileFilter.java
index 3185d76..05dd2d8 100644
--- a/src/main/java/net/sf/javaanpr/gui/tools/ImageFileFilter.java
+++ b/src/main/java/net/sf/javaanpr/gui/tools/ImageFileFilter.java
@@ -19,8 +19,16 @@
 import javax.swing.filechooser.FileFilter;
 import java.io.File;
 
+/**
+ * This class filters filenames using the filename extension.
+ */
 public class ImageFileFilter extends FileFilter {
 
+    /**
+     * This method will accept the given filename if its extension is .bmp, .jpg, .jpeg, .png or .gif.
+     * @param name The filename to check
+     * @return true if the filename has one of the accepted extensions
+     */
     public static boolean accept(String name) {
         int lastIndex = name.lastIndexOf('.');
         if (lastIndex < 0) {
@@ -31,15 +39,25 @@ public static boolean accept(String name) {
                 .equals("gif");
     }
 
+    /**
+     * This method will accept the given file if it is a directory or if it has a filename which is accepted
+     * by {@link ImageFileFilter#accept(String)}.
+     * @param file The file to check
+     * @return true if the file is a directory or its filename is accepted by {@link ImageFileFilter#accept(String)}
+     */
     @Override
-    public boolean accept(File f) {
-        if (f.isDirectory()) {
+    public boolean accept(File file) {
+        if (file.isDirectory()) {
             return true;
         }
-        String name = f.getName();
+        String name = file.getName();
         return accept(name);
     }
 
+    /**
+     * This method returns a description of the file extensions which are currently accepted.
+     * @return "images (*.jpg, *.bmp, *.gif, *.png)"
+     */
     @Override
     public String getDescription() {
         return "images (*.jpg, *.bmp, *.gif, *.png)";