Images Saved with STF are Permanently Altered

[GordonH]

My normal routine is to use STF to examine an image right after ImageIntegration and then save this image. In the past these images would reopen without any stretching. That no longer appears to be true.

If I save the image, close it down, and then reopen, it immediately appears stretched. Resetting in the STF will return it to its unstretched state. However, if I shut PixInsight down and then restart and open the image, it again appears stretched, but, that stretch is now permanent.

Not sure when this started. I recently upgraded to Windows 10 and the the same behavior occurs on both my desktop and laptop computers.

Gordon Hansen

[msmythers]

Gordon

Some time ago there was a major update to PI that embedded the STF settings for an image when saved. This can be disabled for the saved image by unchecking the 'Display Function" check box in the XISF options when saving an image.

As far as the STF not resetting after reopening I don't have that issue on my Windows 7 computer. In the zip file are 2 xisf images that are identical. The first one has the STF saved with the image. The second doesn't. When I open the first one in a newly started PI session I can reset the STF.

Mike

[pfile]

yes the stretch should not be permanent after a restart of PI... if you are seeing this then it could be a bug.

rob

[Juan Conejero]

The "stretch" doesn't exist, that is, the saved image has not been stretched. As Mike has pointed out, this is just an XISF feature to store display functions (aka STF AutoStretch parameters) which, as you know, only affect the visual representation of the image.

[GordonH]

Thanks all for the responses. Another lesson learned!

I did do some more "experimenting." If I reopen a file saved with an STF stretch after restarting PixInsight, it will not re-set by clicking the reset button. You must first click on the AutoStretch button. then the Reset works.

Once again thanks for the help.

Gordon

[mschuster]

Gordon,

After restarting PI and opening STF, the track view (check) button is likely disabled. Click to enable it first and then reset will work.

Thanks,
Mike