NASA / JPL / Cornell / color composites by Stuart Atkinson
Comparing Opportunity raw images to PDS versions
These two versions of color Opportunity images were made from raw JPEGs (left) and archived images (right). Because of the automated contrast stretch applied to the rover "raw" JPEG images, color images produced from them can look odd. In particular, the brightest and darkest areas of any image often have a color cast to them that is not real; bright areas often look yellow, and dark areas often look blue. Also, unusually colored things covering small areas of the original image -- like the glints off the surface of the metallic meteorite -- are simply invisible in the raw versions.