Using JPEG Compression
JPEG (Joint Photographic Experts Group) compression is one of the two standards of image compression, and currently the one with the most options.
Images that are compressed in JPEG format retain most of the colors (within a range of millions) in the original image, while losing a moderate amount of detail. So little detail is lost that most people outside the graphics industry can't tell the difference between the original and the modified JPEG image.
JPEG is a "lossy" form of compression, meaning that each time an image is saved as a JPEG, more of the original information is lost. Fortunately, you can have some degree of control over the amount of the image loss by choosing from various options when saving: from a limited amount of compression (and thus more original detail is maintained) to a much greater amount of compression (and less detail). Using the maximum amount of JPEG compression can reduce a file to 5% of its original size, or even less.
To set Acrobat Distiller to JPEG compression:
Choose Job Options from the Settings menu (Figure 1).
Choose Job Options from the Settings menu.
Click on the Compression tab in the Job Options dialog box (Figure 2).
Click on the Compression tab to view the different graphics compression options.
Change the pop-up menus in the first two sections to JPEG and High.
Click the OK button.
The options change to the choices you've selected. The next time you run Distiller on a file, it will use those compression settings.