All,
The "correct" way to blend a narrowband image, particular an H-alpha image, with its corresponding broadband image, in this case a Red image, has had many comments, questions, and even implementations. I've taken a physical approach to the problem. The narrowband and broadband images both represent mixtures of a background (red) signal and an emission-line (Ha) signal. As such the two images provide a pair of simultaneous equations that allows us separately to estimate their two signal components for each pixel. Then, of course we can remix the red background with the Ha line emission in any proportions we desire to produce an image that can be used wherever the red image would be used, but having enhanced Ha signal.
That is what my icon BLM does (at the dropbox link below). The derivation of the equations (simple) and an example are also in the dropbox file. Hope they are of use. But this is the first incarnation of the algorithm, so use with care.
https://www.dropbox.com/s/1fv6b7wcsdlld0e/BLM.zip?dl=0
Alex Woronow
The "correct" way to blend a narrowband image, particular an H-alpha image, with its corresponding broadband image, in this case a Red image, has had many comments, questions, and even implementations. I've taken a physical approach to the problem. The narrowband and broadband images both represent mixtures of a background (red) signal and an emission-line (Ha) signal. As such the two images provide a pair of simultaneous equations that allows us separately to estimate their two signal components for each pixel. Then, of course we can remix the red background with the Ha line emission in any proportions we desire to produce an image that can be used wherever the red image would be used, but having enhanced Ha signal.
That is what my icon BLM does (at the dropbox link below). The derivation of the equations (simple) and an example are also in the dropbox file. Hope they are of use. But this is the first incarnation of the algorithm, so use with care.
https://www.dropbox.com/s/1fv6b7wcsdlld0e/BLM.zip?dl=0
Alex Woronow