Auto Color Balance

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gustavo_sanchez
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Joined: Fri Oct 12, 2012 3:37 pm
Location: Puerto Rico
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Auto Color Balance

Post by gustavo_sanchez »

There could be an auto color balance option? Sometimes the "Wipe" module does not completely remove the color cast from my images... The method that I am using right now is to do auto color balance in Nebulosity right after stacking, and then importing the image into StarTools for postprocessing.
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admin
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Re: Auto Color Balance

Post by admin »

Hi Gustavo,

Actually, there are a number of ways to further correct color balance in StarTools.
The Wipe function should push you in the general direction, but sometimes it isn't enough.

1. The 'Sample' function in the Color module is a very versatile way to calibrate your color and lets you calibrate against either G2V stars, 'white' galaxies, or - for widefields - aggregated star color. To use this feature, create a mask with the objects you're calibraing against. Click the 'Sample' button to have Color calibrate against the objects. You will notice that only the masked-in objects get calibrated (because only these objects are currently part of the mask). To apply the calibration to the full image, go back into the mask editor, click 'Clear', 'Invert' and return to the Color module. The full image will now be calibrated.
2. You can perform an white balance correction by simply clicking in the image on an area that 'should' be a shade of grey.The Color module will then make sure that it is.
3. The 'MaxRGB' button in the top right corner gives you an alternative view of your data - it shows you the dominant channel per pixel. If you have, or example, a red cast, you can reduce red until red is no longer completely dominant (with bits of green and blue poking through) using this view. It is also the next best thing to owning a color-calibrated monitor, as it is an objective measure for the color balance in your image.

Hope this helps,
Ivo Jager
StarTools creator and astronomy enthusiast
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