You can start Fireworks from Dreamweaver to make quick export changes, such as resizing an image or changing the file type, to placed Fireworks images and animations. Fireworks lets you make changes to optimization settings, animation settings, and the size and area of the exported image.
Clicking Update exports the image using the new optimization settings, updates the GIF or JPEG placed in Dreamweaver, and saves the PNG source file if a source file was selected.
If you changed the format of the image, the Dreamweaver link checker prompts you to update references to the image. For example, if you changed the format of an image called my_image from GIF to JPEG, clicking OK at this prompt changes all references to my_image.gif in your site to my_image.jpg.