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Messages - sharkmelley

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Hi Alejandro,

Thanks for your feedback. No doubt the problem is my own bad program code but it works fine on my Windows 7 PC.

Maybe someone would be kind enough to tell me what is wrong with this code snippet:

Code: [Select]
MainDialog.prototype = new Dialog;

var globalData;
globalData.biasFiles = new Array;      //This is line 1252
globalData.flatFiles = new Array;
globalData.darkFiles = new Array;
globalData.lightFiles = new Array;
globalData.fileSelectDialog = new MainDialog ();


I can then fix it tonight.


I've written a script for calculating DSLR sensor parameters i.e. gain, read noise and dark current profile over a sequence of dark frames.  It will calculate sky fog noise as well if (featureless) light frames are supplied to it.

I hope I've managed to attach a zip file containing the script.  The script should be placed in your PixInsight\src\scripts folder.  The code is probably not brilliantly written (I'm no JavaScript expert) but it does appear to work.

The output is written to the Process Console. Here is a result from a Sony A7S camera at a constant ambient  temperature of 20C:

DSLR Sensor Parameters v0.0.4
Camera: Sony ILCE-7S
ISO speed: 2500
Image Size: 4256 x 2848
Bias frames exposure time: 1/8000 sec
Flat frames exposure time: 1/4000 sec
Dark frames exposure time: 297 sec
Light frames exposure time: 302 sec
Gain per channel(e/ADU):   [ 1.626, 1.607, 1.608, 1.615 ]
ISO for unit gain:         [ 4066, 4018, 4019, 4039 ]
Read Noise(e):             [ 1.33, 1.33, 1.34, 1.33 ]
Dark Current (e/pixel/sec) [ 0.1143, 0.1102, 0.1099, 0.1132 ]
Dark Current (e/pixel/sec) [ 0.1216, 0.1168, 0.1175, 0.1218 ]
Dark Current (e/pixel/sec) [ 0.1281, 0.1239, 0.1238, 0.128 ]
...<snip> ...
Dark Current (e/pixel/sec) [ 0.1675, 0.1606, 0.1618, 0.1666 ]
Dark Current (e/pixel/sec) [ 0.1684, 0.1617, 0.1628, 0.1674 ]
Dark Current (e/pixel/sec) [ 0.1711, 0.164, 0.1639, 0.1683 ]

Noise estimates for 297sec exposure
Read Noise(e):             [ 1.33, 1.33, 1.34, 1.33 ]
Thermal Noise(e):          [ 7.13, 6.98, 6.98, 7.07 ]
Skyfog Noise(e):           [ 46.59, 50.87, 50.88, 37.52 ]

Mean values in ADU
Bias Frame 1: [128, 127.9, 127.9, 128 ]
Bias Frame 2: [128, 127.9, 127.9, 128 ]
Flat Frame 1: [850.6, 881.7, 882.1, 532 ]
Flat Frame 2: [831, 860.6, 861, 520.6 ]
Dark Frame 1: [ 126.9, 126.7, 126.9, 126.6 ]
Dark Frame 32: [ 126.6, 126.6, 126.7, 126.5 ]
Light Frame 1: [1367, 1641.5, 1642.1, 903.6 ]
Light Frame 2: [1479.4, 1787.2, 1787.6, 958.4 ]

DSLR Sensor Parameters v0.0.4 Completed.

The results are given for each of the 4 channels:  R, G1, G2, B

It's fairly straightforward to use (I hope!)
Pairs of raw bias frames and (unsaturated) raw flat frames must be supplied to calculate gain and read noise (in electrons)
To calculate dark current, a sequence of dark frames must be supplied (at least 2)
For skyfog, 2 light frames must be supplied (with the same exposure time as the darks)
All frames must have the same ISO.

The only issue at present is that if dark frames and bias frames are black clipped to zero (which is typical of Nikon behaviour) then the results will not be reliable.  Warnings are produced if black clipping or flat frame saturation is encountered.

The calculations use only the central 25% of the image in both width and height in order to avoid vignetting problems or amp glow effects near the edges.

Any suggestions are welcome!



Excellent - thanks!



I'm working on a script that calculates DSLR sensor parameters and reports on how dark current increases from exposure to exposure.

However, for this to work properly, it is essential that the raw files are loaded as Raw Bayer CFA monochrome.  I can't find any obvious way to do this if the user has already set a different option using DSLR_RAW in Format Explorer.  I'm using ImageWindow.Open to open the files but I can't find any way to specify the Format Hints referred to in this post:

The script output looks like this:

DSLR Sensor Parameters v0.0.1
Camera: Canon EOS 350D DIGITAL
ISO speed: 800
Image Size: 3474 x 2314
Bias frames exposure time: 1/4000 sec
Flat frames exposure time: 1/15 sec
Dark frames exposure time: 305 sec
Channel order:             [RGGB]
Gain per channel(e/ADU):   [ 1.151, 1.101, 1.113, 1.113 ]
ISO for unit gain:         [ 695, 727, 719, 719 ]
Read Noise(e):             [ 5.5, 5.28, 5.42, 5.47 ]
Dark Current (e/pixel/sec) [ 0.133, 0.1271, 0.1247, 0.1256 ]
Dark Current (e/pixel/sec) [ 0.1715, 0.1629, 0.1593, 0.1626 ]
Dark Current (e/pixel/sec) [ 0.2039, 0.1861, 0.2144, 0.1932 ]
Dark Current (e/pixel/sec) [ 0.2338, 0.2149, 0.2443, 0.2837 ]
Dark Current (e/pixel/sec) [ 0.2677, 0.2435, 0.2517, 0.2563 ]
Dark Current (e/pixel/sec) [ 0.2971, 0.2748, 0.2756, 0.3451 ]
Dark Current (e/pixel/sec) [ 0.3234, 0.3035, 0.3007, 0.3158 ]
Dark Current (e/pixel/sec) [ 0.3461, 0.3216, 0.3236, 0.3427 ]
Dark Current (e/pixel/sec) [ 0.368, 0.3433, 0.3447, 0.415 ]
Dark Current (e/pixel/sec) [ 0.391, 0.3665, 0.3663, 0.4315 ]

If it helps, I attach the script here (with txt suffix instead of js)


Hi Juan,

Thanks for your reply and especially for the code fragment.  I'll give it a try.



Is it possible in PJSR to watch a folder for any new image file that is dropped into it so it can then be opened and processed using, for example, AberrationInspector, FWHMEccentricity (or some variant).  The intention is that this would happen in a "hands free" continuous loop.

I'm looking at this in the context of collimating a scope and camera to speed up the process of making an adjustment then displaying the results.



Image Processing Challenges / Re: Playing with DBE Symmetries
« on: 2013 October 30 00:48:59 »
Last night I ws trying to remove a circular gradient and thought the "axial" approach would solve it.  So I set up 10 axial points with 24 point symmetry.  This resulted is a very oval background gradient being calculated.

I did a Google search for "Pixinisight DBE axial" in an attempt to find some documentation that would mayble explain this nonintuitive behaviour.  I found no explanation but found this thread!  So I'm adding my experience to this thread.

I'm using one of the relases of version 1.7 of PixInsight


Wish List / Re: Scripting with Process Icons
« on: 2012 March 25 11:05:24 »
That's great!


Wish List / Scripting with Process Icons
« on: 2012 March 22 23:06:34 »

I have a script that runs a few processes in succession - some are "global context" processes and some are not.   The output files from one process become the input files to the next etc.  I did this because I couldn't put all the processes in a ProcessContainer to run them on multiple files - the ProcessContainer complained when trying to run a global context process.

Unfortunately it means the script has to set up lots of parameter values for the various processes.  What I would like to do instead is to pick up existing process icons (whose parameters I have already carefully set) and use the script to tell those processes which files to work on.   There may already be a way of doing this but I haven't found it!


General / Re: Problem with CosmeticCorrection hot pixel removal
« on: 2012 March 18 11:01:20 »

The new version works great  :)


General / Re: Problem with CosmeticCorrection hot pixel removal
« on: 2012 March 17 02:20:20 »
Hi Nikolay,

I've made a bit of progress on this - I don't know how to single step through the script so I peppered the script with console.writeln!

The problem only happens when I run the script as a process from the desktop (I dragged it there using the blue triangle).

Under these conditions, HotThreshold has a sensible value before the statement
but is zero directly afterwards.

So something is resetting HotThreshold - I think it is something to do with:

Trouble is, I don't understand enough about what is going on to get any further.

Hope this helps!


General / Re: Preprocess and stack while I sleep
« on: 2012 March 17 00:40:44 »
Quote from: mmirot
Checkout new scripts and modules forum
very active thread under calibration and alignment script.
User input is encouraged. Timing for this could not be better.

Thanks - I'll do exactly that!

General / Re: Problem with CosmeticCorrection hot pixel removal
« on: 2012 March 17 00:38:05 »
Hi Nikolay,

I tried 1.7.3 with the same version of PI as you:  PI   Unfortunately I got exactly the same problem with or without Auto Detect.

I guess the main difference is that I am running on Windows XP  :-[ which I know is not officially supported.

I may try to debug it - I'm an experienced programmer but never used Java Script before.   I haven't found the debugging tools (if there are any) so I'll have to write variables to the console or a log file.


General / Re: Preprocess and stack while I sleep
« on: 2012 March 16 18:39:38 »

I've managed to put ImageCalibration, Debayer, StarAlignment and ImageIntegration into a script instead - using mainly the default settings but at least it's a start.  I can point it at my raw Canon CR2 files and the master calibration files then it runs through all the steps and produces a final sigma stacked image without further intervention.   

It'll keep me going until Juan's script is available.

I still find it puzzling that the ProcessContainer refuses to do the same thing.


General / Preprocess and stack while I sleep
« on: 2012 March 16 13:25:39 »
Hi all,

Another question - I already have a whole week of experience with my trial version of PixInsight  :D

Once I've finished an imaging session I like to set off my processing as a batch job and then go to bed.  When I wake up in the morning I have a stacked image (this works well with both IRIS and with DSS).

Following Harry Page's excellent video tutorial, I thought all I needed to do was to put ImageCalibration, Debayer, StarAlignment and ImageIntegration into a ProcessContainer.  I then put my raw files into a ImageContainer and dragged its blue triangle onto the bottom bar of the ProcessContainer.  It began to do its processing but I got error messages like "ImageCalibration can only be executed in the global context".

Am I doing something wrong  :-[


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