Defect Map Questions

[William McLaughlin]

Hi:

My SBIG 11000M has a couple of partial columns that do not respond well to normal dark subtraction so I use a pixel map aka defect map to correct this. I have always done this in MaxIm DL, where you can numerically specify the area to be treated. I noted the new feature in Pixinsight so figured I would try it.

I was able to get it to work by creating a .tiff image in Photoshop with that partial column black and the rest of the image white. What I noticed was that the numerically specified rows for that column were the opposite, or "upside down" in PixInsight vs. MaxIm DL. I assume this has something to do with a different way of reading the fits image for the two programs? Is there a way to deal with this so that the two programs load the images in the same orientation?  I recall noting this in the old Mira vs. MaxIm as well, which would imply that MaxIm is the culprit here.

I would also really be nice to have a simple way to create the pixel map aka defect map image within PixInsight as part of the defect map function that did not itself involve a lot of manipulation of darks and such.

[Emanuele]

Hi H.

As far as the image being upside down with respect to Maxim:
Go into the Format Explorer, click on FITs and then Edit Preferences.
Check the screenshot below where you can set the origin of the image.

[William McLaughlin]

OK, that did it. Thanks!

Had to flip my map image and re-save, but that is easy.

Nice to have program to program consistent.

Just out of curiosity, which is the standard, or is there one?

[Carlos Milovic]

In photography the standard is top left. Professional astronomy, and some other technical fields, bottom left.


You may use PixelMath to create the map, or write a small script that draws lines, paints individual pixels, etc.

[William McLaughlin]

Any way to run a defect map on a whole set of files short of writing a script (which is presently beyond me)?

This would seem to be something that one would want to do a lot.....

[Carlos Milovic]

You should be able to batch apply it with a Image Container.

[William McLaughlin]

You should be able to batch apply it with a Image Container.

Sigh!  I found that but have no idea how to use it. This illustrates just how desperately a good manual/help system is needed!

One should not have to post to or search the web/forum to learn the basics of a program! That is a huge waste of time for the user and the
developers as well as the forum participants. There are some nice PixInsight tutorials out there, but one cannot have a tutorial on every aspect of a program,
that is what help and manuals are for.

We don't have a written user manual. Given the complexity and extension of PixInsight, a manual to document all the tools available would be more like a course book on image processing algorithms and techniques. There are many and excellent books on these subjects; all of them much better than anything we could write. More importantly, we believe that such a huge and complex manual would be mostly useless to our users.

I have to disagree rather pointedly with the above quote from the FAQ. I AM a newbie at PixInsight but am far from a newbie (http://nightskypictures.com/cred.htm) at astro-imaging and I still flounder trying to deal with the interface and implementation of the processes. This is a great example of what is lacking in PixInsight since I understand exactly what the process is doing, I just have no idea how to make PixInsight do it (on multiple images). It is not a lack of knowledge about the concept or the process, just about the program and the interface.

In fact, I really do suspect this is impacting sales of PixInsight significantly. Many, if not most, new users would most likely download the trial and soon throw up their hands in frustration and go buy something either simpler or with better documentation, or both. In fact, I know of just such a person (I recommended he try PixInsight) who is not only an experienced imager but an engineer as well. If I understand him correctly as to why he is not using Pixinsight, it is because he just does not have the time to puzzle out the interface.

It is only because of the power of the program - it does some things other programs just cannot do - that I continue to persist in learning it despite the annoyance and frustration of trying to learn the interface by trial and error and poking here and prodding there.

I, for one, would happily pay significantly more for a set of manuals and tutorials covering all aspects of the program! That would be worth 10X more to me (and I suspect others) than any other new feature one could possibly think of.

I can't wait for version 1.6 with it's (hopefully complete) help system. I hope that when it does appear it is complete and makes no assumptions of prior knowledge (at least with regard to the interface). In fact, I may just wait until it appears before I even try to proceed any further up the learning curve for the interface. That could save me a fair amount of frustration, it seems to me.

Any idea when that release will be?

[Ioannis Ioannou]

I would also really be nice to have a simple way to create the pixel map aka defect map image within PixInsight as part of the defect map function that did not itself involve a lot of manipulation of darks and such.

http://pixinsight.com/forum/index.php?topic=2183.0

I guess you are looking for DefectMapExtractor, you will find it about the half of the thread

[William McLaughlin]

I guess you are looking for DefectMapExtractor, you will find it about the half of the thread

Well that is helpful, but in my case it is just as easy to map the defects by manually making a hot column image since there are only three partial columns which do not change.

At present the my issue is how to make the Image Container work to batch this correction.

[Ioannis Ioannou]

Well, I'm a newbie, so let me see how I can assist you.
I did this on the fly, mainly out of curiosity, I did not knew the Image Container functionality (*) .

I have a directory with a few lights

I create a bad pixel map somehow (eg the script I mentioned before)

I opened the ImageContainer, click on the yellow button at the middle to add my files into it, and then drag-drop the triangle at the bottom left on the desktop, to create a new instance of it on the desktop

Now I opened the DefectMap tool, defined my defect map view on it, and drag the triangle of it over the icon on the desktop I created before : voila, the black screen started rolling and all of my files have been magically fixed !!

Not so bad, if you consider that I did not even knew how the tool works. The only things I needed was understanding how PI instances work (a few hours using PI gives you a feeling about this)  and positive attitude to explore the tool



(*) off topic there are a lot of things that I do not know in PI and image processing but I do not agree with your comments regarding the interface

[William McLaughlin]

I opened the ImageContainer, click on the yellow button at the middle to add my files into it, and then drag-drop the triangle at the bottom left on the desktop, to create a new instance of it on the desktop

Now I opened the DefectMap tool, defined my defect map view on it, and drag the triangle of it over the icon on the desktop I created before : voila, the black screen started rolling and all of my files have been magically fixed !!

Not so bad, if you consider that I did not even knew how the tool works. The only things I needed was understanding how PI instances work (a few hours using PI gives you a feeling about this)  and positive attitude to explore the tool

(*) off topic there are a lot of things that I do not know in PI and image processing but I do not agree with your comments regarding the interface

Yes, that worked fine. The problem, for me, is the interface is just not well explained anywhere - at least that I can find. If anyone has a link to explain the basic interface please let me know.

I stand by my comments on the help/manual. Not just because of my own experience but because of what other imagers have said. Many just do not use PixInsight for this very reason. What they say is that it is different enough to require the very thing that is missing - a manual.

[Carlos Milovic]

For the moment, maybe the best source is Harry's videos... then, review the documentation of the LE release (under free downloads, as a legacy). It is pretty obsolete, but the main idea of how things work are well explained there (previews, drag & drop object, etc).

[William McLaughlin]

For the moment, maybe the best source is Harry's videos... then, review the documentation of the LE release (under free downloads, as a legacy). It is pretty obsolete, but the main idea of how things work are well explained there (previews, drag & drop object, etc).

OK, I think I looked at those a year or so back but am not sure. Imaging for me has been very hit and miss in the past few years due to various unrelated circumstances so that is part of the problem for me, what I did know about PixInsight, I mostly forgot! I will have a look in any case.

Do you have a projected release date for 1.6 and it's much improved documentation (at least to judge from the samples posted)? I would not hold anyone to a date, just trying to get an idea (for example, less than 6 months, more than a year, whatever).

For what it is worth, often a help file or link may be better than a tutorial, especially to answer just one small question or explain one small feature, since it saves watching a bunch of stuff you know just to get to one item that you do not know. Not to denigrate tutorials as they are great and have their place as well.  It all depends on what one needs to know at the moment!

Thanks!

[Carlos Milovic]

I think that 1.6.2 could be released anytime... bug fixes and maybe a few new features. Not sure if it will include the new upgrade system. About the documentation, it will be released gradually along the 1.6.x cycle. To have everything covered, I think it would take at least 6 months... but the crucial parts should be done by christmas.

[William McLaughlin]

I think that 1.6.2 could be released anytime... bug fixes and maybe a few new features. Not sure if it will include the new upgrade system. About the documentation, it will be released gradually along the 1.6.x cycle. To have everything covered, I think it would take at least 6 months... but the crucial parts should be done by christmas.

Cool. Thanks!