Hi,
Bicubic spline works but I agree with Mike, you loose in resolution.
I hope this is something can be fixed and prioritized in the next developments.
I'm afraid this cannot be fixed or improved, as far as I know. When it comes to choose an interpolation algorithm, you have to decide between:
- Better detail preservation and less aliasing, but more ringing: Lanczos.
- Less detail preservation and more aliasing, but less ringing: Bicubic spline.
- Poor detail preservation and lots of aliasing, but zero ringing: Bilinear.
In our implementations of Lanczos and bicubic spline, I added a clamping device that limits ringing generation. Of course, this feature also has its own drawback: clamping increases the low-pass behavior of the interpolation filters, which degrades interpolation and leads to more aliasing. However, the clamping feature provides finer control that in most cases allows you to use Lanczos or bicubic without having to resort to bilinear.
Generally, interpolation ringing artifacts disappear after integrating a sufficient number of frames, when they can be rejected as outliers. This usually happens, for example, with ringing generated around stars. Ringing around hot pixels can be more persistent. In these cases you can use cosmetic correction to remove all hot pixels before registration (BatchPreprocessing allows you to automate this).
