Ok, further update...
I have uploaded a new version this morning 4.1.11388, which has some hopefully useful improvements to the planetary stacking.
Compared to the 4.1.11368 interim version, the changes are
- Add option to halve wavelet scales
- Add colour channel alignment
- Fix crash on PNG timelapse
- Add TIFF option to save timelapse
- Save TIFF/PNG timelapses as 16 bit images to allow for further processing
- Allow AVI timelapse when camera in 16 bit mode
- Add a brightness adjustment for the planetary stack
- Remove final wavelet level 5 (have not found it useful, removing it speeds up procesing)
- Add checkbox to view unprocessed frames
Some of these deserve a little more discussion...
Halving wavelet scales
I found that the sharpening worked pretty well on over-sampled images, but couldn't be tuned to give good results on smaller images that were either under-sampled or near critical sampling.
I suspect that in time I will have to re-do the sharpening code, which is a little crude, but an effective way to get much improved results turned out to be to double the size of the image, wavelet sharpen the zoomed image, then rescale back to the original size. This is what the 'Halve wavelet scales' option does behind the scenes - it will slow down processing, but will probably only been needed for relatively small ROI captures anyway, so that should be OK.
Colour alignment
This option will digitally re-align the Red and Blue channels with the Green as the image is being processed (before sharpening). It is only enabled if the checkbox is checked *and* the measured offset of either the blue or red channels from the green channel is at least 1 pixel. As well as helping suppress blue-one-side-red-the-other fringes on the image, it will also help with general sharpness as it will align the image features better across the image.
Note that an ADC will still do a better job, since the image processing approach cannot do anything about blurring within the colour channels caused by dispersion across the range of the colour channel.
Brightness Adjustment
Brightness is a bit of an inaccurate name for this, but I struggled to find an accurate name that wasn't either too long or potentially confusing in some other way. A traditional brightness control lifts the brightness of each pixel by the same amount. This instead scales up pixel values by a constant multiplication factor, so if you choose 1.2 it will make all pixels 20% brighter than they were. It's handy if your camera images are a bit under-exposed, allowing you to brighten the output image without affecting the stack. I suspect that I may have to change this in a later update to be one of a brightness/contrast pair.
cheers,
Robin
