Added progress dialog display to 'Add Thumbnail Icon' and 'Convert Image' functions, which let users cancel the operation anytime in the middle.
Increased the speed of making thumbnail icon (3 times faster than before) by eliminating of generating small icons. (Now only 128x128 dot icon is generated).
Added a preference option whether to add or not to add black frame to thumbnail icons.
Improved the image quality of thumbnail icons.
Added 'Delete Resource Fork' function which eliminates extra data from image files in addition to thumbnail icons.
Added Label button to the main view window, which let users add/remove label easily for organizing images.
Changed all blank menu items to separator lines in pulldown menu at main view dialog.
Fixed a bug of undo/redo processing during file switching back and forth.
