Mars Global Surveyor Mars Orbiter Camera Image Gallery

About the Processed Images

There are as many as five processed and two unprocessed versions of most of the images in the MOC Image Gallery:

Processed

• Small, 400 line, JPEG compressed (with loss) image that has been processed and map-projected;
• Medium, 800 line, JPEG compressed (with loss) image that has been processed and map-projected;
• Full-size (up to many 1000's of lines), JPEG compressed (with loss) image that has been processed and map-projected;
• Full-size (up to many 1000's of lines), GIF losslessly compressed image that has been processed and map-projected; and
• Full-size (up to many 1000's of lines), GIF losslessly compressed image that has been processed but not map-projected.

Unprocessed

• Full-size decompressed but otherwise unprocessed image in PDS .IMG format; and
• Full-size data set in raw MOC compressed (PDS .IMQ) format.

Processed MOC images in this gallery have been treated as follows:

1. Pixel-to-pixel and overall shading variations introduced by the instrument have been removed using the best available calibration data as of the date of release. Two forms of power supply noise (a periodic pattern of dark-bright-dark and a random component) have not been removed as the techniques for this processing are still being developed.

2. Map-projection into sinusoidal and polar stereographic projection was accomplished using the final spacecraft and planet ephemerides and reconstructed spaceraft pointing. Processed/projected images are presented with north to the top and the sun generally illuminating the scene from the left.

3. Each image has been contrast-enhanced by performing a linear contrast stretch saturating 0.1% to 0 DN and 0.1% to 255 DN.