How to combine luminance to RGB data

[Jim_]

I know I'm missing something.
I've searched the forums but can't fine exactly what I'm looking for.
How do I combine two layers into one.
I make a false luminance layer and do all my sharpening on that and then combine it with the RGB in photoshop.
There has to be a way to do this but I haven't found it yet.
Any advice???

Jim

[Nocturnal]

I dunno, seems like the LRGB tool is exactly what you want?

Of course most PI processes can be applied directly to the L of the image so what you're proposing is a bit cumbersome. When I want to mess with L I simply mess with L. I don't extract, manipulate and re-apply.

[Jim_]

I'm still on the trial version so I'm probably going about this in a way i don't really need to.

Does PI work on the luminance layer only?
sorry for such a newbie question but this is like learning a complete new way to process.
I've worked with PS for so long all I know is that way of working with layers.

PI does seem to be a great program though.
I don't know why it hasn't caught on more.

Jim

[Nocturnal]

Hi Jim,

glad you're trying out PI, I hope you like it. Look for checkboxes that say things like 'Luminance' or 'Lightness' only. ACDR (noise reduction) for example can be applied to L or Chrominance or both. Same for wavelets, histogram, curves etc. Give it a try. If you find a process where it doesn't work, let me know and I'll see if I can help.

[Jim_]

I dunno, seems like the LRGB tool is exactly what you want?

Where is  the tool located?
I can't seem to find it.

[Nocturnal]

I don't have PI here to check but they're all listed in alphabetical order under 'all processes'. Shouldn't be too hard to track down.

[topboxman]

If you captured L, R, G, and B, then you will most likely need to do "LRGB Combination". That's under "Color Spaces" category.

PixInsight wrote a nice LRGB tutorial at:

http://www.pixinsight.com/videos/NGC1808LRGB-vperis/en.html

There's a bunch of other tutorials at:

http://www.harrysastroshed.com/pixinsighthome.html

Peter

[Nocturnal]

Jim wanted to do this:

- extract L
- process L
- reapply L

So that would become:

- extract L
- process L
- extract R, G and B from original image
- combine R, G, B and new L into new image

This can still be done but I recommend exploring if it's really needed in this case.

[topboxman]

OK. Like I said, use "LRGB Combination". To learn how to apply "L" to RGB is follow the tutorial from the link I provided.

Extracting "L" from RGB is simple by using a button icon in tool bar at top of screen. I am at work so I don't remember what the icon looks like. Open RGB image and click on the button icon and the Luminance image will pop up. Process this image and use "LRGB Combination" to apply L to RGB.

Peter

[Jim_]

If you captured L, R, G, and B, then you will most likely need to do "LRGB Combination". That's under "Color Spaces" category.

That's the one.
See, I knew I was blind.

Thanks all for the help!!!
This seems like a great AP processing program...just a large learning curve.
I'm sure I'll go ahead and get the full license for it.

Jim

[Nocturnal]

Nah, learning curve isn't so bad. The issue is that you're used to working with mystical layers in PS that do 'magic' things. In PI you manipulate the image with named processes. I think it's easier to explain what wavelet processing does than what 'dodging' is, for example.

Spend some time with Harry's videos. They're great.

[topboxman]

I used Photoshop for three years and was still struggling. Then I saw PixInsight and available tutorials and suddenly PixInsight made sense. After about two weeks of learning from video tutorials, I was processing my old images much better than what I did with Photoshop.

You will not regret purchasing PixInsight. I bought PixInsight after only two days with 43 days left of free trial.

Peter

[Nocturnal]

I started AP with PI when it was still in beta, somewhere in 2006 or 2007. As it went GA I tried for a while to do AP on the cheap with fitsworks, PI LE, nebulosity and paintshoppro. That just wasn't cutting it. Of course I really didn't know what to do anyway. That's when I bought PI and the rest is history.