PixInsight Forum (historical)
PixInsight => Bug Reports => Topic started by: twade on 2008 April 05 16:51:58
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To PTeam,
I just noticed PixInsight is not preserving the original FITS header information. For example, here's the original FITS header information:
SIMPLE = T
BITPIX = -32 /8 unsigned int, 16 & 32 int, -32 & -64 real
NAXIS = 2 /number of axes
NAXIS1 = 4096 /fastest changing axis
NAXIS2 = 4096 /next to fastest changing axis
BSCALE = 1.0000000000000000 /physical = BZERO + BSCALE*array_value
BZERO = 0.00000000000000000 /physical = BZERO + BSCALE*array_value
OBJECT = ' '
TELESCOP = ' ' / telescope used to acquire this image
INSTRUME = 'Finger Lakes'
OBSERVER = ' '
NOTES = ' '
DATE-OBS = '2008-04-03T06:13:33' /YYYY-MM-DDThh:mm:ss observation start, UT
EXPTIME = 600.00000000000000 /Exposure time in seconds
EXPOSURE = 600.00000000000000 /Exposure time in seconds
SET-TEMP = -35.000000000000000 /CCD temperature setpoint in C
CCD-TEMP = -35.062500000000000 /CCD temperature at start of exposure in C
XPIXSZ = 9.0000000000000000 /Pixel Width in microns (after binning)
YPIXSZ = 9.0000000000000000 /Pixel Height in microns (after binning)
XBINNING = 1 /Binning factor in width
YBINNING = 1 /Binning factor in height
XORGSUBF = 0 /Subframe X position in binned pixels
YORGSUBF = 0 /Subframe Y position in binned pixels
FILTER = 'Lum ' / Filter used when taking image
IMAGETYP = 'Light Frame' / Type of image
OBJCTRA = '12 34 14' / Nominal Right Ascension of center of image
OBJCTDEC = '+10 31 35' / Nominal Declination of center of image
TRAKTIME = 2.0000000000000000 /Exposure time used for autoguiding
FOCALLEN = 0.00000000000000000 /Focal length of telescope in mm
APTDIA = 0.00000000000000000 /Aperture diameter of telescope in mm
APTAREA = 0.00000000000000000 /Aperture area of telescope in mm^2
SWCREATE = 'MaxIm DL Version 4.61' /Name of software that created the image
SBSTDVER = 'SBFITSEXT Version 1.0' /Version of SBFITSEXT standard in effect
FLIPSTAT = ' '
SWOWNER = 'Thomas W. Earle' / Licensed owner of software
INPUTFMT = 'FITS ' / Format of file from which image was read
SWMODIFY = 'MaxIm DL Version 4.61' /Name of software that modified the image
HISTORY Bias Subtraction (Bias 3, 4096 x 4096, Bin1 x 1, Temp -35C,
HISTORY Exp Time 0ms)
CALSTAT = 'BDF '
HISTORY Dark Subtraction (Dark 18, 4096 x 4096, Bin1 x 1, Temp -35C,
HISTORY Exp Time 600s)
HISTORY Flat Field (Flat FSQ (Lum) 02Apr08, 4096 x 4096, Bin1 x 1,
HISTORY Temp -35C, Exp Time 1s)
PEDESTAL = -100 /Correction to add for zero-based ADU
CSTRETCH = 'Medium ' / Initial display stretch mode
CBLACK = 6615 /Initial display black level in ADUs
CWHITE = 8461 /Initial display white level in ADUs
Here's the FITS header after using DynamicAlignment and saving the file:
SIMPLE = T / file does conform to FITS standard
BITPIX = -32 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 4096 / length of data axis 1
NAXIS2 = 4096 / length of data axis 2
EXTEND = T / FITS dataset may contain extensions
COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
PINSIGHT = 'PCL 01.00.37.0178' / PCL: PixInsight Core Class Library
COLORSPC = 'Grayscale' / PCL: Color space
RESOLUTN = 72. / PCL: Resolution in pixels per resolution unit
RESOUNIT = 'inch ' / PCL: Resolution unit
ICCPROFL = 'ICCProfile' / PCL: File includes ICC profile extension
INPUTFMT = 'FITS ' / Format of file from which image was read
As you can see, all the original header has been destroyed. Is there a setting in PixInsight to preserve this information? I would highly recommend preserving the original data and just append PixInsight information to the header.
Thanks,
Wade
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Hi Wade,
I would highly recommend preserving the original data and just append PixInsight information to the header.
This is in fact what happens when you open an existing FITS file and save it as a new FITS file. In this case, all (valid) original FITS keywords are always preserved.
However, when you generate a new image with DynamicAlignment, it doesn't inherit FITS keyword settings automatically from the original image. I agree with you that the original keywords should always be preserved in these cases.
Count on this problem fixed in the next version. In the meanwhile, a workaround is to assign the original keywords manually with the standard FITSHeader process:
- Ensure that the original image is the active image in PixInsight's workspace.
- Select File > FITS Header
- Drag an instance from the FITSHeader window to the registered image (the new image generated by DynamicAlignment). Optionally, you can create a process icon if you want to save the whole FITS header as a .psm file.
Thank you
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Hi Wade,
Count on this problem fixed in the next version.
Hi Juan.
The problem not solved in 1.4.0 ver ?
Batch process erase important information in FITS Header.
Best regards,
Nikolay.
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Hi Nikolay,
The problem not solved in 1.4.0 ver ?
Batch process erase important information in FITS Header.
Indeed. This is my fault - I just forgot to solve this problem in 1.4. Thank you for pointing it out.
Although my credibility has been certainly damaged :lol: I promise this will be fixed in 1.4.x.