About the Image Files:

The files in the "IMAGES" directory are images corresponding to the
"Relief Globe Slides" available from NGDC. The image files are stored in
several formats compatible with both DOS and Macintosh systems: .GIF
(8-bit Graphic Interchange Format), .HDF (8-bit format for NCSA Image),
.TIF (24-bit), and 8- and 24-bit Macintosh PICT. In addition, there is
an 8-bit representation of the GeoSat Antarctic gravity anomaly image
(.GIF, .TIF., .HDF, and PICT). Most of the images are 640x480 pixels in
size; a few are larger. Software is included in this CD-ROM to view the
images on both DOS and Macintosh computers; a color display is
recommended on both.

In the directory "RGBImage" is a representation of world relief on a
Mercator projection, stored as red-blue-green separations in a plain
raster format. Each component image is 4680 x 3320 pixels in size, with
8-bits per pixel. There are several commercial packages that can be used
to view the component images or combine them into the full-color
composite.