heya,
'Adobe ImageReady' should come bundled as part of your photoshop.
If you have your file open in Photoshop, go to file>edit in imageReady. ImageReady should open straight up. then you can then compress it more in ImageReady, or if you are happy with the file size then go to File>Save Optimised As..and under 'format' select 'html and images'... save this file where you want and then you can open the html page in dreamweaver no problem.