Problem with saving fits files in Pixinsight

[viktorbravo]

I'm new to the software (previously used CCDStack, PS, Maxim) and I am having trouble saving a fits file in Pixinsight.  For some reason, it doesnt like the information in the fits header and thus will not save the file when I "save as".  I dont have an issue with my fits headers with any other software. 

Sorry for the newbie question, but am I missing something?

Thanks, Vince

[sreilly]

What other software reads the files fine? Can you post one of these images?

Steve

[viktorbravo]

Pixinsight reads and opens the files just fine, but it will not save them due to it not liking the fits header information.  I have been processing and saving fits images with the same fits headers for years using Maxim, CCDStack, Registar, Sigma, Ps, etc.

I am using the trial version, maybe it will not allow me to save fits files?  I really want to like this software but its a very steep learning curve.

[sreilly]

I've never had any issue with PI not allowing me to save a file in fits format using either the "save" or "save as" command and I've consistently used MaxIm for my image acquisition software with ACP for automation. If PI can read and open the image there isn't any reason I can see it wouldn't save the image. Again, can you make one of these files available for download so I can see what you are experiencing?

[viktorbravo]

Here is the message I am getting when I use "save as".  It doesnt like a character used in the fits header when I register using registar.

Writing file:
/Users/vbert/Documents/Astro Images/NGC 7000/Oct2011/NGC7000-105/Ha/NGC7000proc.fit
*** PCL Exception: PCL FITS Format Support: Error writing FITS header keyword:
/Users/vbert/Documents/Astro Images/NGC 7000/Oct2011/NGC7000-105/Ha/NGC7000proc.fit
CFITSIO error message stack:
01 : Character 53 in this keyword is illegal. Hex Value = FFFFFFA9
02 : REGISTAR=                      / RegiStar Copyright © 2000-2005 Auriga Imaging 
<* failed *>

[viktorbravo]

OK, figured it out.  For some reason Pixinsight doesnt like what Registar adds to the fits header.  I had to remove all references to Registar out of the header and now it will save the fits file.  Strange, no other software I have used had a problem with what Registar adds to the fits header.

Baby steps.    Now back to the learning curve....

[Juan Conejero]

Hi Vince,

A copyright symbol is illegal in a FITS header keyword. Only ASCII characters are allowed as per the FITS standard. PixInsight allows you to read these files, but our policy is to prevent propagation of illegal FITS files. Standards exist to be observed.

You can easily remove or edit the offending header keywords with the FITSHeader tool (select the image, then select File > FITS Header from the main menu).

[viktorbravo]

Thanks again for the response Juan.

I am not using copyrighted material, but I use Registar on all of my images, and the software is copyrighted.  Registar puts the symbol into the fits header.  If you use Registar on the image, it puts their copyright on the registration process.  Its a simple matter to remove the symbol, but a bit of an annoyance.  Nothing else I have used on my images does this.  Is this something to do with European law?

Anyway, I am getting more familiar with Pixinsight and I like it very much.  Its such a different way of doing things that it takes quite a bit of reading and video watching to get going, but so far, so good.

Thanks again, Vince

[Juan Conejero]

Hi Vince,

No, this doesn't have anything to do with 'legal matters'. The FITS format is defined by a standard maintained by the IAU FITS Working Group. The problem isn't with putting copyright information in the images, but with the use of a text character that is not permitted by the FITS standard. If instead of a © symbol it were '(c)', then there would be no problems because '(', 'c' and ')' are valid ASCII characters.

Other software applications are lax regarding standards compliance, but PixInsight is rigorous. I'm glad to know you're enjoying PixInsight. and I'm sorry for the inconvenience with these nonstandard FITS files.

[viktorbravo]

No worries, thanks for the explanation Juan.

[RBA]

No worries, thanks for the explanation Juan.

Viktor you may actually want to write to the author of Registar and tell him he's adding the © symbol to the FITS header, which, as Juan explained, it's not allowed by the FITS standard. You don't have to mention other software chokes on that (the usual reaction to that sometimes is just "ok so tell the author of the other software not to choke). See if you get a positive response and actually get this guy to release an update even if it's only something as simple as DELETING the © symbol from a string in the code.

AFAIK, Registar is a one-trick-pony that hasn't had a worthy update in years, yet the author cashes in from every license he sells almost as much as what PixInsight costs.

I'm sorry if I sound a bit sour... About three years ago I asked for a simple request to be added to Registar  I had to send the email 2-3 times before getting a response. I finally got a response in the line of "yeah, we'll be doing an update soon, trust me, we're still very much behind this software", and NOTHING has happened ever since. Of course, now I could care less, since PixInsight has completely replaced the only task I was using Registar back then, ever since PixInsight included its registration routines, but it still bothers me the little care some people put into their own software but charge top dollars for it.

[viktorbravo]

I only use Registar because it doesnt choke on the 16803 images and delivers consistent, good results for me.  Its a "use what I know" kind of thing.  I'll start using PI to register the images soon as I learn more about the software.  Baby steps. 

In any case, I like the fact that the developers of PI are responsive to the customers and provide very good support.  I would like to run my entire processing routine in PI, so I am slowly migrating toward that end.

[Andres.Pozo]

Instead of failing when writing files with invalid characters, Pixinsight could replace the offending characters with an space or underline and emit a warning.

[Juan Conejero]

Hi Andrés,

Instead of failing when writing files with invalid characters, Pixinsight could replace the offending characters with an space or underline and emit a warning.

Two good reasons to not do that:

* Modifying metadata generated by other applications can be problematic. For example, who am I to modify copyright information generated by other application?

* With very few exceptions, other applications make no effort to be compatible with PixInsight. We have done big efforts to be flexible enough as to allow importing data from virtually any application (for example, floating point data can be read with arbitrary ranges, coordinate orientations can be customized, we have a format hints system to facilitate this, etc.). We have even implemented support for some nonsensical formats, such as CCD raw data stored as signed integers. But frankly, asking us to fix the mistakes made by other competing products is asking for too much. Ask them to back their software and fix the problems they are generating. This is just what we do with hard work everyday.

[RBA]

I only use Registar because it doesnt choke on the 16803 images and delivers consistent, good results for me.  Its a "use what I know" kind of thing.  I'll start using PI to register the images soon as I learn more about the software.  Baby steps. 

I'm not criticizing those who use Registar. I'm sharing my thoughts on a product that is not cheap for what it does, yet is not supported properly. In many cases, the software business is more about support than development, but some people seem to think that "develop once, sell it for life" is an appropriate business model.