How do I combine 2 images

[pyrasanth]

I have 2 registered L images.

One has nice round stars & average galaxy detail. The other image has very nice galaxy detail but distorted stars.

I've used the clone stamp tool to remove the distorted stars on the image with the bad stars. I now have a nice galaxy image with no stars and an image with good stars but a weak galaxy image

I want to merge the 2 images perhaps using Pixel math keeping the good parts from both images. I hope the composite will give me the best elements from each image.

Please can you explain how to do this.

Thanks

[TobiasLindemann]

What happens, when you just add the two images? (Image1+Image2)/2
If you want only the brightest pixels (maximum) of both images try: max(Image1,Image2)
Tobias

[Geoff]

1. Use LinearFit to adjust images to the same brightness.
2. Make a preview around the "good" galaxy.
3. Use the SubstituteWithPreview script (Scripts > Utilities > SubstituteWithPreview) to transfer the galaxy preview to the image with the good stars.
Geoff

[pyrasanth]

1. Use LinearFit to adjust images to the same brightness.
2. Make a preview around the "good" galaxy.
3. Use the SubstituteWithPreview script (Scripts > Utilities > SubstituteWithPreview) to transfer the galaxy preview to the image with the good stars.
Geoff

Thanks!- that works really well and it is very simple. I think its down to understanding the available scripts and what they do. I have only been using PixInsight less than 6 months but its power amazes me.

Is there a way to create a preview freehand- I can only set a box around an object at present- is there a way to more closely follow the contours of an object. I keep thinking PS where you can use a free hand or magic wand type of tool- let me know if this is possible.