Why can't I combine my L channel with RGB please?

[stevek]

Hello, I have my Luminance image open on the desktop and also my RGB image likewise opened.  Please see attachment. So with the LRGB combination tool open I select the Luminance image on the L box and the with the triangle I drag this onto the RGB image on the desktop, assuming it will combine the L with RGB.  But it throws an error saying it cannot find the RGB.  But it is on the desktop!

However, if I select the luminance as above, clear the RGB checkboxes and select the RGB image (that is on the desktop) in the "target" select box and THEN drag onto the RGB it goes off and works.  But does this process create a combined LRGB image?  A bit confused!

Many thanks, Steve

[AstroScience]

From the image it seems that you have also R G and B channels box ticket. Since they not specified it throws an error on the first R channel missing.
You have to un-check the R G and B channels and try this again.

I see that you already doing so and yes, it does creates combined image (Luminance channel being replaced by the one you have specified) when you have selected only L and applied it to an RGB image.

[pfile]

yes - with the checkbox ticked and <auto> in the field, PI tries to take a guess at the name for the image. so just untick the RGB boxes as AstroScience says.

[stevek]

Thanks Guys, but what about me specifying the RGB image - open on the desktop - in the "target" drop down menu - after clearing the RGB tick boxes.  It all seemed to work but did that create the combined image?
Thanks.

[AstroScience]

Steve,
for your specific task you don't have to use "Target" drop down menu.
Just tick the L box, select your Luminance image , un-tick the R, G and B boxes and drag triangle instance on to your image. That will do it.
If you didn't preprocessed your Luminance image, you won't see any difference.
Try to set Saturation from 0.5 to 0.2 and you will notice color boost after combining L.


The "Target" drop down selection is useful when you have extracted all channels from specific image, then selecting that image as target and LRGB tool will automatically select the corresponding  R G B channels.

If you didn't saw this yet, watch both parts of NGC1808 LRGB video here: http://www.youtube.com/watch?v=zqhLKIjGMXA it would be really helpful.

[stevek]

Wahoo!!!!!!    Thats it!  Thanks so much guys!  I just need to uncheck the RGB tick boxes and it worked!