I'd agree that any image processing involves changing an image in some way, and point out also that it's a matter of choosing and balancing the changes to improve an image. The raw streaks are themselves a distortion of the image, and on balance, to me removing them improves the image.

The destreaking algorithm is pretty accurate under certain circumstances. It works best on an image which overall has roughly the same average brightness everywhere. The algorithm changes an image most when it has a distinct brightness variation on the horizontal axis. Terminator shots show the most dramatic change, brightening the shadowed side and toning down the bright side. Vertical brightness variations undermine the column average used to determine the correction factor, and so residual streaking will be visible in that kind of image. The destreaking algorithm is far from perfect, but I think in most cases its use is beneficial.

I can't think of a technical reason why using the destreaker would remove fine detail. I think your impression is subjective--the streaks are sharp-edged, and removing them may give the impression that the image is somehow "softer". There is, possibly, one pathological case in which this might actually happen: If the image happens to have a long linear feature that's aligned very close to vertical in the image. Then, for obvious reasons, the algorithm would "perceive" the feature as a streak and remove it. Such features are rare in nature...I guess it depends what you're looking for, doesn't it? ;-)

My algorithm works on simple column averages. MSSS has a more advanced destreaking algorithm that's based on the derivative of column-to-column variation--it acts as a high-pass filter. It occurs to me that the MSSS filter actually could result in "softening" an image by attacking sharper brightness changes more heavily. But I have to admit that their algorithm will destreak much lousier images than mine will.

By the way the spiders are amazing, even like worms at the bottom.

Nice try, but this fish ain't gonna bite on that worm. I can see the hook!

--Robert