From: ken@home.nz.retro.com   
      
    wrote in message   
   news:1126122024.614175.203320@g44g2000cwa.googlegroups.com...   
   > When a photograph taken under sodium light is later viewed in normal   
   > lighting it appears a much deeper orange compared to the subjective   
   > experience of being there. The brain performs automatic "white balance"   
   > correction when it is immersed in colored light. This correction is not   
   > as strong when the image only fills a small part of the field of vision   
   > and the rest is illuminated by white light.   
   >   
   > NASA carefully calibrates the colors of published images to match the   
   > spectrum of ambient light on Mars. Would these pictures really match   
   > the subjective experience of actually being there some day?   
   >   
   > The first Viking images received from Mars were not color-calibrated. I   
   > believe each color component was individually stretched to cover the   
   > full range to maximize SNR with the highest gain applied to the   
   > relatively weak blue signal. The result was an image that looked as if   
   > it was taken somewhere in Arizona, with blue skies, reddish rocks and   
   > even some greenish patches. The color calibration was later changed to   
   > the much redder hues we usually see.   
   >   
   > Some conspiracy theorists claim that this Earth-like view is what Mars   
   > really looks like. I wonder if there is actually some truth in their   
   > claims. No, I don't think NASA tweaked the colors "to make it look more   
   > alien" because of some sinister motives. Perhaps the color correction   
   > applied is just a little too correct?   
   >   
      
   IIRC the color enhancements were initially incorrect and were recalibrated   
   after an image including the American flag was sent back. The red was   
   noticed to be way out.   
      
   Ken   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)