Saving...

[jdonald]

I am processing my first image and when I try to save the finished product it doesn't save it as I see it on the screen, its like it is saving an unprocessed image, even if I use Tiff.  The only way I can show the image as I see it on the screen is to take a screenshot of my desktop.  Am I missing something?

Thanks
Jeff

[Nocturnal]

Hi,

sounds like you have a ScreenTransferFunction (STF) applied?

[jdonald]

Yessir I do

[Nocturnal]

Well there's you're problem. As the name implies STF does not change your image, it only changes how data in your image is mapped to data on your screen. Unfortunately STF is not saved with your image so it's not there when you load the image again. So make permanent brightness changes with processes like the histogram or curves transformation tools.

[jdonald]

I was going by the tutorials, what a waste STF is.  Is there an easier way? I just spent hours working on this and having to start over is frustrating

[Nocturnal]

I'm not sure which tutorials you're referring to but I'm suspecting there's a misunderstanding somewhere. STF is an essential part of PI and similar methods are used in other software so there's nothing weird about it. Finding a proper STF should take about 5 seconds as you press the 'A' button for automatic.

[jdonald]

I am using Harry's Tutorials, I press A for auto, but I just don't know how to make that Permanent   Sorry for the noob questions, but I am lost lol.

Jeff

[Nocturnal]

I haven't watched Harry's tutorials but I imagine he explains what the STF is for. Perhaps review the same video again. What is his next step? Perhaps a histogram transformation? That would actually change the image data, making it brighter if that's what you want.

I wrote a series of articles for Astro Photo Insight that go over a typical processing sequence like this. If you're not a member yet it's well worth the fist full of dollars. Not just for my content of course but for all the other things people have written as well. I'm pretty sure membership gets you immediate access to back issues.

I'd summarize my typical processing sequence here but I'm afraid it would overwhelm you.



PS the only reason I haven't watched Harry's videos is that he put the first ones up around the time I wrote my articles and I didn't want to copy his material by accident. I really should sit down and watch them all now.

[Nocturnal]

On this page

http://www.harrysastroshed.com/pixinsighthomenewbie.html

watch all the vids or at least the STF and Histogram ones.

[pfile]

you can apply the auto-STF (or any STF) to an image by:

1) dragging the STF's triangle to the bottom of the HistogramTransformation window (to the strip where the HistogramTransformation window's own triangle is)
2) applying the HistogramTransformation to the image, either by dragging the HT triangle to the image, or if the image is the topmost window, by clicking the blue square.

after doing this, it's a good idea to reset the HT (4 arrows in the bottom right corner of the window) because the STF->HT manipulates the R,G,B channels instead of the combined channel and that can lead to confusion afterward.

don't be surprised if your image goes all white after this - that's because the STF is still applied. just turn it off after applying the HT.

you are not the first person to be fooled by this, but as sander says such "screen stretches" are a part of any good astro processing package...

[Harry page]

Hi

Yes please do watch the video again , as I do go to great lenths to explain that the STF does not alter your data 


Harry

[jdonald]

Thanks for the replies, I have been meaning to check out that astrophoto insight.  Pfile, that worked like a charm, I will post my first AP image later on.

Harry, wonderful videos, I will be watching them again.  Learn something new each time.

Jeff