You can use LiveWriter Onscreen to blog an image from the web or from a file.
Select "Blog image from local file" or "Blog image from web".
A dialog window like the one shown below is displayed. Enter the title for the image and comments and click ok. LiveWriter will be launched with the title, comments and selected image inserted into the editor. Now you can blog away.
These images will be uploaded to your pre-configured FTP server.