Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We're currently using PixelSense to convert raw SPOT5 images to natural color ones for display and printing. Do you know a good algorithm to perform the same task as we want to ingest raw images in an image server and provide an image service with on the fly natural color conversion.

share|improve this question
up vote 3 down vote accepted

An option is to perform these steps:

  • generate a synthetic blue channel
  • balance the colors by outlier removal through analysing the channel historgrams. For a GPL'ed approach, see here
  • then create the RGB composite

Concerning the generating of a synthetic blue channel:

Since I don't have SPOT5 data here, I cannot make a test. But I found this formula (Knudsen):

Blue_synth = 0.70 × Green + 0.24 × Red - 0.14 × NIR
share|improve this answer
The first step is where the magic lies, I guess. Care to elaborate please ? – GuillaumeC Nov 27 '10 at 23:11
I have edited my previous answer, see above. – markusN Nov 30 '10 at 21:43

If you are using ESRI software; check out this thread:

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.