Speedster allows you to control the display quality of web page images. By decreasing the image quality, you increase the download speed of web pages. You can tell Speedster how much to compress images, or to not compress them at all.

Right-click the Speedster icon
Click Settings...

Under the Image Quality tab, move the bar to the left or right to adjust the amount of compression for web page images
The images above the bar give you a preview of how images will look on the web
Click OK when done