Looks good in xifs format, however...

[Bill1054]

Rank newbie processing first comet image.  I like the result, but only while it remains in the PI friendly format.  Saving as a tiff or jpeg results in loss of all faint detail which is this case is both the ion and dust tails.  I must be overlooking something, and would much appreciate some help.

Thanks,
Bill

[NGC7789]

It's hard to tell you what you may have overlooked if you don't tell us what you did. What were your processing steps? Also screenshots or links to the two results would be helpful too.

[pfile]

you probably used the screen transfer function to adjust the histogram. by default, XISF can save the state of the STF on the image, leading to the impression that your stretch was permanent when you close and re-open the XISF.

or, it could be that you applied an STF, then applied some real histogram changes on top of that (using the HistogramTransformation or Curves tool), but those changes are not significant compared to the STF, so what gets written out to jpeg or tiff does not look right.

STF is just to make linear data visible on the screen - it does not change the underlying data.

is there a green bar along the left side tab showing the name of the image? that's the indicator that the STF is on.

rob

[Bill1054]

Rob-  Many thanks, I'm so new at this I didn't know about the green line, nor had I found the icon that enable/disables the STF.  Now I'm an iota better informed.  May I live long enough to find my way around in PI!

Bill

[jkmorse]

Bill,

I have a workbook that I freely share that may help.  If you are interested, just drop me a line at jkmorse57@gmail.com.

Best,

Jim