PI Workflow question

[Stephane Murphy]

Hi, first I most say that I am addicted now to PI, great software.

I am having some issues with my current workflow and I was wondering if the sequence of execution is correct, in this example I am using M13.

1- I have a master RGB float 32 bit (created with CCDStack for now, still learning how to use PI for this task) and the data is still linear.
2- Applied a STF
3- Applied DBE on the STF image - Seem problematic
4- Background neutralization on the STF image
5- Color balance on the STF image
6- Deconvolution on the STF image
7- Reset the STF image
8- Applied histogram and other processing on the RGB

Does the step above seem correct?

Any suggestion would be appreciated.
Thank you
Stephane

PS: Sorry for my english!

[Nocturnal]

Hi,

I'm curious about the color balance and background neutralization as well. I think it can be applied at any stage, on linear and non-linear images but I'd like to hear from the experts about that.

What is the problem with DBE? You you start a separate thread for that so we don't mix topics.

[mmirot]

I agree with Saunder.
I would adjust color last although it really does not matter because it is a linear operation.

Also, If you check normalized on DBE it is now already neutral.
If you apply your decon to luminance only then the background should stay neutral.
Then you will just need color adjustment after decon.
There is no reason to do it again.

This is my linear workflow. I don't see too many reasons to stay linear after these steps.
I like to do a real Histogram strech next.


Max Mirot

[Stephane Murphy]

Hi Max and Sander, thanks for your feedbacks. It makes sense now, because the data is still linear it should not matter when I applied linear processing functions.

As for the DBE problem, I will post a separate thread. Basically I am finding it difficult to create a model with only STF stretch, I can’t reveal the gradient very easily.

Thanks again
Stephane

[mmirot]

Tip,

The STF tool is much improved in 1.5.2 however there is a neat fine tuning trick in one of the Videos Juan produced.

First, Have STF tool open.
Go to histogram tool. Turn on RT preview in the histogram tool.
Strech and fine tune the image with the histogram tool until you can see the gradient properly in RT preview.
Drag and drop the apply instance triangle ( lower left corner in histogram) on to the STF tool.
The histogram settings majically transfer to the STF tool an can be apply to the image as a STF rather than permenent histo strech.

Max

[Stephane Murphy]

WOW, never heard of this functionality before, great trick. I'll give a try tonight when I come home.

Thanks you
Stephane

[Fco. Bosch]

MMirot said

Drag and drop the apply instance triangle ( lower left corner in histogram) on to the STF tool.
The histogram settings majically transfer to the STF tool an can be apply to the image as a STF rather than permenent histo strech.

And vice versa!! drag and drop the automatic STF to histogramTransformation and he settigs of STF are nor permanent

[Nocturnal]

WOW, never heard of this functionality before, great trick. I'll give a try tonight when I come home.

Thanks you
Stephane

Time to review the videos again Stephane!

[Stephane Murphy]

I guess so:) Do you know what video is covering this trick?

[Niall Saunders]

Hi all,

For this to work, you need to drag the 'triangle' to the 'bottom bar' of either the STF or the Histo window (i.e. STF to Histo, or Histo to STF)

HTH

[Nocturnal]

I guess so:) Do you know what video is covering this trick?

Sorry, that I don't remember I think actually tonight I'll review them myself again as well. You could review the transcripts of the videos to quickly pin point the one you're interested in if you don't have time to view them all.

[Stephane Murphy]

Also watch them again tonight, it's suppose to rain anyway.
Stephane

[Nocturnal]

So I'm also looking at the 'correct' order of things. Do DBE first or first neutralize the background? With my OSC images the background tends to be very green due to the sensor being most sensitive there. If I subtract the background first then it's effectively subtracting the green background and the result is almost neutral. If I first neutralize the background then DBE removes the residual gradient. I guess I'll have to try both and see how it works out.

[Simon Hicks]

Hi all,

Nobody has mentioned smoothing (ACDNR) and where its fits in the 'optimum process flow'.

Am I right in suggesting that it is best to apply this to the linear image with STF applied?

If so, then is there an advantage in applying it before the DBE and colour correction (or background neutralisation)? I have a modded Canon 400D, so the red channel is much higher and obviously has a better S/N ratio than the other channels. That's why I suspect (but I'm not 100% sure) that it would be best to apply smoothing BEFORE the DBE and colour correction stages.

Is this right?

Cheers
         Simon

[Nocturnal]

Hi Simon,

I prefer to use the luminance mask with ACDNR to protect high SNR areas. It's easier to identify those if I first stretch the image. So I first do DBE, then stretch and then do ACNDR. Then perhaps another stretch and ACDNR.

Of course more than 1 way lead to Rome so be sure to experiment and tell us what works for you!