Super Structure module with star mask

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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firebrand18
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Joined: Tue Feb 04, 2020 1:43 pm

Super Structure module with star mask

Post by firebrand18 »

Hello,

Really appreciating the new Super Structure module functionality; works great.

I have a question around what Ivo mentioned last week for this:

"Having many uses for final image presentation after colour and detail have been brought out to taste, the usage of the Super Structure module is chiefly recommended as one of the last processing steps. The use of a mask is possible for selective processing, however if uncompromised documentary value of the final image is desired (e.g. the image is to be presented as a photo, rather than art), then relying on the model as extracted from the dataset itself is highly preferable."

My mantra is to keep images as "true" as possible without "creative manipulation". That being said, before this latest rev, I sometimes used Guy's "Star Shrinking Under Tracking" Notes to push back heavy star fields and bring forth subject detail, but used a mask only on stars, not subject itself:

Mask, Auto, Fat Stars, Grow x2, then Auto, Stars, Add New to Old, Do, Invert", run Life module with default Isolate preset.

Is this an acceptable form, both with previous Life and new Super Structure modules to keep an image "true" or does it skew things? I figure since the mask is only on stars and not the subject, considered documentary value?

Thanks for any guidance.
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admin
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Re: Super Structure module with star mask

Post by admin »

That's a really good question!

Using masks to do selective processing can be anywhere from OK, to gray area, to a pitch-black-do-not-go-there area. :)

The rule of thumb is generally this; if the software (mask generator) uses only an automated algorithm that purely uses the image itself as an input to generate the mask, then the resulting mask is still "OK".

The line - for many - is when data/knowledge is manually introduced that was not part of the image as recorded, when that data/knowledge cannot (was not) derived from the contents of the image itself.

Note that it also depends on the module with respect to how the module uses a mask. The Wipe module, for example, does not use the mask to perform selective processing, rather it uses it to perform selective sampling to construct a model that is still applied to all pixels evenly and not selectively. E.g. it does not (should not) create any artificial outlines.

I hope that makes sense!
Ivo Jager
StarTools creator and astronomy enthusiast
firebrand18
Posts: 13
Joined: Tue Feb 04, 2020 1:43 pm

Re: Super Structure module with star mask

Post by firebrand18 »

Good reply, and makes perfect sense.

So if only using the "Auto" Stars feature in a mask to just select Stars, inverting then doing Isolate, you are simply pushing stars backwards and bringing the subject (nebulosity) forward without altering it in any way? That would be "Ok" in your opinion and still "photo" worthy?

Just getting it really well defined.

Thanks.
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Re: Super Structure module with star mask

Post by admin »

firebrand18 wrote: Tue Nov 03, 2020 2:33 am Good reply, and makes perfect sense.

So if only using the "Auto" Stars feature in a mask to just select Stars, inverting then doing Isolate, you are simply pushing stars backwards and bringing the subject (nebulosity) forward without altering it in any way? That would be "Ok" in your opinion and still "photo" worthy?

Just getting it really well defined.

Thanks.
Indeed, the auto-mask generation relies wholly on an algorithm that uses the image itself as in input, so it would indeed be "permissible" (I am not the arbiter of that, you are!) in that sense.
Ivo Jager
StarTools creator and astronomy enthusiast
firebrand18
Posts: 13
Joined: Tue Feb 04, 2020 1:43 pm

Re: Super Structure module with star mask

Post by firebrand18 »

Thanks Ivo, "Less is more" as I always say! Cheers.
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