Author Topic: Image integration  (Read 1635 times)

Offline Harry page

  • PTeam Member
  • PixInsight Jedi Knight
  • *****
  • Posts: 1455
    • View Profile
    • http://www.harrysastroshed.com
Image integration
« on: 2009 November 24 12:15:55 »
Hi

I notice when using Image integration with a RGB image ( From a OSC camera) that different weights are given the RGB channels from the same image some times very different weights  In  One for red 1.5 for blue and 2 for red ( These are made up numbers but you get the idea)
Even though I see little difference the final image , doesn't this unbalance the image   ???

Any input   Ideas welcome


Harry
Harry Page

Online Juan Conejero

  • PTeam Member
  • PixInsight Jedi Grand Master
  • ********
  • Posts: 6715
    • View Profile
    • http://pixinsight.com/
Re: Image integration
« Reply #1 on: 2009 November 26 01:51:43 »
Hey Harry,

Quote
different weights are given the RGB channels from the same image some times very different weights

The different weights are computed from automatic noise estimates for each channel, as you're using the automatic noise evaluation weighting method. With this method each channel is treated as an independent image. The computed weights will provide the highest possible SNR improvement in each channel of the final integrated image.

Quote
doesn't this unbalance the image

The resulting RGB image can be slightly different if you use a weighting method where equal weights are assigned to all channels: either the "don't care" method, or the "exposure time" method, for example. The differences can be larger if your images have been acquired under varying conditions: different exposure times, ambient temperatures, or even different light pollution and atmospheric conditions. However, automatic noise estimation will always yield the best result in terms of SNR increment.

It's up to you, but I bet you'll prefer less noise and more signal, even if this means altering the inherent color balance of your image set. And we have very good color calibration tools!
Juan Conejero
PixInsight Development Team
http://pixinsight.com/