Creating a synthetic Green channel?

[Emanuele]

HI all...
what is the best way to create a synthetic Green channel just using R and B, in PI?

Thank you!
E.

[caliu]

Pixel Math, is the best way,
You can assign it deems appropriate percentage, uncheck "Use a sinlge RGB expression" and edit G, enter the percentage of R & B that seems more convenient, then configure the destination and press F6, get a new image with the synthesized green channel.

Cheers

[Ginge]

Caliu, where can I learn PixelMath syntax? I have no idea how to write the expression below as I have no experience whatsoever with programming, apart from Basic back in the days.

If I want to combine 20% of an image called "OIII" and 20% of one called "SII" with a greyscale image called "Ha", what exactly would the expression look like?

Best regards,
Ginge

[caliu]

For example:



This is just a small example,
You can assign the percentage you wish to each channel, dividing or multiplying by 0.20 or by the value you want, you can add multiple images among themselves, subtract, divide, whatever you want ... remember to always open images in space work 

[Ginge]

Thanks a lot Ferran! Do you also know of resources anywhere on the web where I can learn this syntax so I don't have to ask every time I want to use PixelMath?

Clear skies,
Ginge

[Andres.Pozo]

Thanks a lot Ferran! Do you also know of resources anywhere on the web where I can learn this syntax so I don't have to ask every time I want to use PixelMath?

Clear skies,
Ginge

You can start with the tutorial of PixelMath.

[Ginge]

Oh well, it seems PixelMath is as I suspected, not for me . I've seen this tutorial before and it assumes the reader already has some programming skills other than
10 PRINT "GINGE IS A NERD";
20 GOTO 10
RUN
- which I don't. I'll leave it alone then and make my synthetic greens elsewhere.

Thanks anyway,
Ginge

[Emanuele]

thank you caliu

[caliu]

thank you caliu

Yep  , to make a new channel only is necessary blend two images in the correct proportion, not need to be a computer genius

[mmirot]

Oh well, it seems PixelMath is as I suspected, not for me . I've seen this tutorial before and it assumes the reader already has some programming skills other than
10 PRINT "GINGE IS A NERD";
20 GOTO 10
RUN
- which I don't. I'll leave it alone then and make my synthetic greens elsewhere.

Thanks anyway,
Ginge

I don't like typing stuff myself. However, It is easier than you imagine.
To be sure, there some fairly elaborate operations.

You are asking about the most basic
Max

[Ginge]

You are asking about the most basic
Max

I know, and asking for help every time, either with a supersimple prosedure like this or with a more elaborate one like automating equalisation of gain from a 4-output ccd, is not what I want to be doing. Problem is, if one doesn't know the PixelMath grammar even the simplest issue is out of reach.

However, having had good help on several PixelMath issues, I'm now beginning to see a pattern, hehe. I feel I'm understanding more of  the abovementioned tutorial better now that I read it again.

But thanks for helping! Especially with the basic stuff 

Best regards,
Ginge

[Simon Hicks]

I do sympathise with you Ginge. I remember reading through the PixelMath tutorial the first time and not having a clue at the end of it. I have picked it up just by seeing examples....and now I realise that its actually very simple and intuitive....once you have the basics laid out.....much simpler and accessible than the tutorial suggests. I think the PI newbies would really benefit from the PixelMath tutorial being rewritten in a much simpler form based on simple examples. 

[Ginge]

Hi there Simon!
I think so too, the tutorial is probably very thorough and well written, but to freshmen it can actually seem a bit daunting. I'm not giving up though, was fooling around with PixelMath just now and I think I'm am making some progress 8). Having seen how useful a tool it can be, I really want to learn how to use it.

Clear skies,
Ginge