Most images you get from the web (by right-clicking the image and choosing save image) are already optimized and should work well, but remember to credit your source...are you allowed to use this image?
Images that come from your digital camera, for example, are far too high in resolution and should be scaled down, because a) you won't notice the difference in quality when viewed online and b) the graphics will load much faster.
Images for the web must be in one of three formats: .JPG, .GIF, or .PNG
If you re-size pictures directly in Dreamweaver, the images are not optimized for web delivery. In other words, if it was a 6 MB file prior to re-sizing in Dreamweaver, it is still a 6 MB file and will take a long time to load.
If you have Microsoft Word, here is another option for scaling images:
- Insert the images you want to use in a MS Word document.
- Size them visually using the tools in Word.
- Save that Word document as a web page
- This will create a folder (xxx_files) in the same location where you saved the new html version of the Word document
- Copy these images into the local computer's folder used by the Dreamweaver site (perhaps "images"?).
- Now go into Dreamweaver and insert the images where you would like them.
- They should load as the same size defined in Word with no need to adjust.
- Lastly, add the ALT text and you are ready to go.