New Tool: Superbias

MikeOates

Well-known member
Dec 13, 2012
278
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No one has mentioned this yet, but how do you use the vertical and horizontal option. Setting this produces two superbias frames. Do you combine them in some way?

Mike
 

Juan Conejero

PixInsight Staff
Sep 2, 2004
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Valencia, Spain
pixinsight.com
No, you use just one orientation, the one that fits your bias frames. This is normally the vertical (columns) orientation. The horizontal orientation is available in case you have to work with rotated bias frames for some reason, and also for other analysis tasks, different from generation of superbias frames. For example, you can use both orientations to discover "hidden" oriented structures in your images.
 

ftherrmann

Well-known member
Jan 17, 2013
83
0
Thanks for the 24bit STF button info.  Seems like this should be included in the tool also, but I've never used it until now so not really sure it would do much other than to clutter up the control.  Maybe a tab or menu access from the STF function box?

I enabled the 24 bit and while the moire type pattern does get better it's still there.  Is the a function of not using enough bias files?

Thanks,

Fred
 

Juan Conejero

PixInsight Staff
Sep 2, 2004
8,380
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Valencia, Spain
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The 24-bit STF feature was released in November 2013. See this tutorial for a complete description.

There can't be moir? patterns (a special type of aliasing effect) in a superbias. However, if you look at a superbias frame at a reduced scale on the screen, especially with reduction factors of 1:3 or smaller, there can be visible aliasing patterns as a result of fast/inaccurate screen renditions of the fine bias column pattern. For a correct visualization, take a look at the superbias frame with 24-bit STF enabled at its actual size with a zoom ratio of 1:1, or at half its size with a ratio of 1:2.
 

pscammp

Well-known member
Nov 26, 2013
121
2
England, UK
Hi all,
    and you think your newbies  LOL

So here i have a master Bias from 21 frames aquired with a modded
Canon 1000D DSLR and the master was produced by PI (if i even got
that right)

Not sure if i fully understand what this 24bit SFT thing is but let
me tell you tell you what i did and you can tell me if i did wrong.

1. Opened my Master Bias

2. Normal SFT applied

3. Clicked the little icon at the top of the screen which has got '24' on it (image changed a bit)

4. dropped the Superbias triangle on the image & got a black image as a result

5. Tried dropping the STF's triangle on the new image but the image stayed black and the STF's
    3 bars just reset back to default in the center of it's view (Bit Confused Here)

6. Then i just applied standard STF to the Superbias image (looked real rough)

7. Clicked on the '24' button again with the superbias version selected and the result is on the
    right in the attached pic.

Both pics in the attached image have the '24' button applied to it and the '24' was applied to the
origonal bias master before applying the Superbias to it.

So the big question is:

Is this what i want or is it horribly wrong  ????

Many Thanks All
Paul
 

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TobiasLindemann

Well-known member
Nov 27, 2011
126
0
www.tracking-station.de
Hi Paul,

the picture you posted looks like a normal bias. So everything you have done is correct.
Btw.: you don?t have to use the STF at all. It is only for better visibility, you know.

To point 5: if you activate the "track-view"- button, the STF will be reset by the new picture.

Greetings
Tobias
 

Attachments

pscammp

Well-known member
Nov 26, 2013
121
2
England, UK
Cheers Tobias,

  I almost got something right  Wooo Hoooo

    So i assume then that this new 'Superbias' image i have here is used in place of my origonal 'Master Bias'
for the calibration/integration proccess etc

If so, what settings would i use for the .fits file when saving it, It defaults to a 32bit IEEE 754 Floating Point,
would it need to be a different one like 64bit for instance  ?????

Thanks
Paul
 

Juan Conejero

PixInsight Staff
Sep 2, 2004
8,380
467
57
Valencia, Spain
pixinsight.com
eridanibrew@gmail.com said:
After experimenting, I found that the IMAGTYPE keyword in the Fits header needed to be changed. PI is using "Master Bias", while Maxim is looking for "BIAS". When I changed this keyword, the frames worked as expected.

I am another ACP user, so I need to use Maxim for image collection. Calibration is very convenient, since the images are calibrated as they are collected. I do not have to do anything, the calibrated images are ready the next morning. I use PI for alignment and everything after that.
Make sure that the other application is able to support the normalized [0,1] range that PixInsight uses to write floating point images, or the superbias frame won't work at all.
 

TobiasLindemann

Well-known member
Nov 27, 2011
126
0
www.tracking-station.de
Paul
pscammp said:
    So i assume then that this new 'Superbias' image i have here is used in place of my origonal 'Master Bias'
for the calibration/integration proccess etc
yes
pscammp said:
If so, what settings would i use for the .fits file when saving it, It defaults to a 32bit IEEE 754 Floating Point,
would it need to be a different one like 64bit for instance  ?????
I think 32bin floating point is enough.
 

mfulmer

New member
Feb 23, 2012
4
0
I'm probably doing something stupid... but I can't find the Superbias tool.  I'm running 01.08.02.1098 Ripley on OS X Mavericks 10.9.4. 

Note - I am able to make it work by manually installing the module from http://www.astrophoto.cl/Research.html.

Mike

 

pscammp

Well-known member
Nov 26, 2013
121
2
England, UK
mfulmer,
    Did you search for the tool in 'Resources/Update/Check For Updates' from inside PI, that's where I
found it, the one from your link is probably not the full release version the guy's have released.

You should find it in the 'Image Calibration' sub folder if it's already there, if not then 'Check for updates'
will show it up for you.
 

mfulmer

New member
Feb 23, 2012
4
0
I did.  There was nothing under the Image Calibration sub folder (I'm assuming you mean in the process explorer).  So I checked for updates and nothing was there.  I had performed the update earlier, so it does show that the update for Superbias was applied.  That's when I tried the module from astrophoto.cl - just to make sure it would work.  Then, super bias showed up under Image Calibration.  Should I re-install PixInsight?
 

mfulmer

New member
Feb 23, 2012
4
0
Actually - here's what the Manage Modules tool says about Image Calibration:

Module Id ............ ImageCalibration
Version .............. 01.01.06.0175
Language ............. eng: English
Development status ... <* Unspecified *> (release)
Release date ......... 2014/6/23
Company .............. Pleiades Astrophoto
Author ............... ImageCalibration: Juan Conejero, PTeam / DefectMap: Carlos Milovic F., PTeam
Copyright ............ Copyright (c) 2009-2014, Pleiades Astrophoto
Trade marks .......... PixInsight
Original file name ... ImageCalibration-pxm.dylib
API version .......... 147
Module Description:
PixInsight Standard ImageCalibration Process Module


Installed Updates has this to say about ImageCalibration:

Package type : Module
File name    : 20140705-macosx-x86_64-module.tar.gz
Release date : 2014-07-05 00:00:00
Install date : 2014-07-12 16:18:22
This update installs a new version of the standard ImageCalibration module for PixInsight 1.8.2. Version 1.2.0 is an update release:
* New Superbias tool. The Superbias method was created by Vicent Peris and initially implemented by Carlos Milovic in 2011. This update installs an improved version of this tool, completely revised and reimplemented as an official PixInsight tool on all platforms. For more information on the Superbias algorithm, see the following thread on PixInsight Forum:
http://pixinsight.com/forum/index.php?topic=3269.0
Copyright (c) 2014 Pleiades Astrophoto S.L.

That looks like a problem (01.01.06.0175 vs 1.2.0) - thoughts?

And let me know if this post is trending in a direction where I should post this in another area of the forum.

Mike
 

mfulmer

New member
Feb 23, 2012
4
0
Ok, never mind - I've restarted everything again and now it's showing up. :tongue:

Thanks for the help, pscammp.