RPictureResize is a simple and useful utility. It provides following features with just few clicks operation.
1. Scan folders recursively and save pictures(JPG, BMP,GIF,PNG)
2. Resize multiple pictures with given resolution in batch mode
3. Save resized pictures from different folders into single one
4. Save resized pictures to an new folder which is under original pictures
5. Override resized pictures
6. Slim. It's just 158KB.
7. Support both English & Traditional Chinese languages
8. No installation is required.
9. Free!

The license of this software is Freeware, you can free download and free use this image resizer software.