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Narrowband mixed methods - clarification

starfield
in PixInsight
Hi Adam, 

Just watched your new mixed methods video and I'm trying to wrap my head around how the NB color mapper and NB Normalization tools interact.  

So, let's say in the NB Color Mapper I map my SII color to orange.    When I get to the NB Normalization tool and select boost SII am I now boosting the orange instead of the normal red (for SHO at least)?     I guess what I'm asking is if the NB Normalization tool boosts the SII or OIII colors based on the palette assigned to these channels in the Color Mapper?    Thats kind of what I'm expecting but what to make sure I've got this right.

Thanks, Steve

Comments

  • BlockHeadBlockHead
    The answer (if I understand your question) is no. NB normalization knows nothing about the image (or what you have done to create it... say previously from NB ColourMapper).

    What NB normalization does is to equalize the color channels (of RGB) based on a REFERENCE channel. When you tell NB normalization what the "pallette" is, you are basically telling what band is in which RGB channel. Furthermore, NB normalization will take the channel that you put the Ha into and use it as a reference channel to equalize the other channels. 

    So if you make a color image in NB ColourMapper- and you chose an arbitrary color mapping... the "Ha" band doesn't exist in any strictly independent channel of Red, Green, or Blue... you have mixed things by picking your own colors. 

    However, based on what I said above.. you can see what will happen. Whatever mapping scheme you choose will determine how the image is affected. If you pick HSO for your palette and you have orange in your image (which information in both the red and green channels)..then I would expect any blues in your image to become more pronouced because H=Red, S = Green, O= Blue... so the Green and Blue are normalized to the Red channel since the H is the reference. If you change the palette to SHO... now H is in the Green Channel...   

    On top of all of this, is the adjustment you can make with the Lightness assignment as well.

    So...I probably wouldn't try to predict things if you take an arbitrary color image and put it in NB normalization. You can, by thinking carefully, figure it out... but really just selecting the choices and see what happens can probably be an easier way of discovering the pattern.

    -the Blockhead
  • starfield
    Thanks, for the explaination.    Makes sense now.
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