Hi folks -
Here's a workflow for getting rid of interference fringes in solar images.
Let me start off by saying that the best way to remove interference fringes / Newton's Rings from images is to use a tilt device to correct for the problem at its source.
However, if you have an image that you like and it has an objectionable case of interference fringes, then this approach should help ameliorate the problem.
1. Download and install ImageJ (freeware from NIH) - https://imagej.nih.g...j/download.html
2. Launch ImageJ and open the offending image (you can drag and drop image files such as FITS or PGM onto the ImageJ window to open them) - Here's a single frame from back in July of 2013: