|
I can't claim to be an expert in how the Quality Estimate function works, but I think that the image is compressed and ppmcentre uses the result of the compression to determine how much 'information' is in the image and therefore its quality (a fuzzy image will have less information).
I have had problems with the quality estimation function in Registax if I have a mixture of darker and lighter frames, so I think that is where the problem lies. In those cases, I just made sure I picked the sharpest frame I could find as the reference frame in Registax.
You can save your preferred settings as the new default. Just change the settings on the ppmcentre tab and select File|Save ppmcentre options on the Menu.
Adam.
|