18. Generation of color separation negatives from different 
filter views of the same scene 
  
Figure 12.--Mariner 9 image processing: upper left, picture as received; 
upper right, after linear contrast enhancement; lower left, after local 
contrast enhancement; lower right, after vertical automatic gain control 
In addition to these image manipulation algorithms, the computer 
system produces project control information: 
19. -Plotting of picture footprints on reference graticule 
20. Cataloging of picture data 
21. Generation of navigation data parameters 
When photographic operations have been completed, a control net 
will be computed.  Procedures are described in reference 21. This will 
be followed hy preparation of photomaps at 1:5,000,000 scale.