This data set is a digital archive of images acquired by the Viking Orbiter 1 and 2 spacecraft. The archive will include the best available Experiment Data Record (EDR) versions of images acquired by the Viking Orbiter Visual Imaging Subsystems (VIS). The archive is stored on compact read-only optical disk media (CD-ROM) for distribution. The EDR image data are stored on CD-ROM in a compressed format that allows exact reconstruction of the original image. The images were compressed in order to reduce the number of CD-ROMs required for the archive. The average Viking Orbiter image is compressed by a factor of about 3.5. Each CD-ROM in the archive also includes documentation about the organization and contents of the disk. Software is included to provide programmers with tools to decompress image files. The CD-ROM has index files containing information about all the images stored in the archive. These index files can be loaded into a database management system to help the user locate images of interest.