What would be the minimum required overlap as a %-age of frame width/height?
I would say, that APP needs about 10% of frame width/height for most cases but it strongly depends on several factors.
– the amount of detected stars at the borders of the frames, the more stars detected, the less % it needs.
– the pattern recognition engine creates patterns in the frame to be aligned at different scales and different areas of the frame. These patterns are then compared to patterns found in the reference, also at different scales and areas. The actual implementation of this can be a limiting factor as well. I will test this on @mauricetoet’s data.
So depending on the data and the relative orientation of the reference and frame to be aligned, the percentages could actually be in the range of roughly 2% to even 25 %.
If you are planning to create a mosaic, for best results, I would advise to have at least 15% overlap and preferably a bit more. The more stars that are detected, the higher the chance that registration will be perfect.
@keesscherer, what % did you use in planning your 6 panel Virgo cluster mosaic?
I will have a look at Maurice’s data later today, I’ll make an assessment of the amount of overlap for these 2 frames where registration fails and will report my findings. I hope this data helps me in reducing the required % of overlap for any dataset ?