Jan 10, 2022 · Pixelmath expression: RGB/K: ~((~starless)*(~stars)) Replace the "starless" and "stars" wit your image files.-Chris White PS- This is the expression the Russ provides with StarXterminator. It's a seamless blend. EDIT- I see that is covered in the link Rob provided.

Jun 1, 2022 · Here is another example: let’s say we want to combine RGB stars with a narrowband nebula image. Here are M20’s stars from above combined with a starless image of a portion of NGC6188 using the add-subtracted-stars method. This is again astronomically perverse, but illustrative. I chose the positioning of the stars strategically to show the ...

Oct 5, 2023 · A partial way round this is to recombine using "pseudo-linear" data. This approach means returning a stretched image to a state where pixel values are small by applying a "reverse" stretch. Stars can then be replaced and the inverse of the reverse stretch applied to return to the non-linear state you started out in.

Jul 11, 2023 · Bill Blanshan and I have released a new script designed to help add and remove stars from images. The script features a preview window so you can see what you are doing! The basic approach is the commonly used screening and unscreening methods, however, we have incorporated an additional...

Jul 22, 2022 · The expression I used to use to create a stars only image was a simple subtraction, 'full_image - starless_image' , but when I referred to "subtracting" stars in the way the video describes, I really just meant removing.

Jan 3, 2023 · Removed stars from image with StarXTerminator. Having trouble adding the stars back into the image with pixelmath. Tried a couple of different expressions but always get a white background.

Jul 4, 2022 · If you want the stars to end up roughly the right colour, you should probably run PCC on the image before separation; then, if your "creative processing" of the starless image dramatically modifies the colour balance, your stars can be restored without "christmas tree" effects. The bigger problem is non-linear modifications to the luminosity.

Feb 22, 2025 · Well, there just aren't enough stars in the images. Not sure why. Part of the problem might be poor S/N because of your massive oversampling, 0.38"/pixel and 4.5" stars. You could try scaling down your images by at least a factor of two before processing (which requires a little more work with OSC data).

Aug 6, 2019 · Don't use star mask, use pixel math as below: To save the stars as a separate image use PixelMath Original - Starless = Stars To put stars back in again use PixelMath Starless + Stars = new image with stars The Stars image is in effect the best star mask you will ever get

Dec 5, 2019 · If you've selected Large-Scale Pixel Rejection on either of the scripts' flats tab, or in ImgInt to help eliminate stars in your sky flats, this is likely the cause. Interestingly, if 'Optimize dark frames' is not selected, this seems to bypass the issue, though I've yet to understand why. When both Optimize and LSPR are selected, master darks ...