<p><code>STIFF</code> needs the data in a single HDU without extensions. I was able to fetch the data from the MAST query form by selecting <code>IMAGE</code> types, <code>ACS</code> as the only instrument, <code>F606W</code> as the filter and searching around (RA,Dec)= (104.66499909807, -55.954761771866). Once you've got the data down, you need to split out the <code>SCI</code>(ence) extensions (there are two, one for each chip in the ACS <a href="https://hst-docs.stsci.edu/acsihb/chapter-4-detector-performance/4-2-the-ccds#id-4.2TheCCDs-4.2.54.2.5CCDReadoutFormat" rel="nofollow noreferrer">Wide Field Camera(WFC)</a>) from the (complicated) Multi-Extension FITS (as you have tried). The trick is to write it into a new empty <code>PrimaryHDU</code>:</p>
<pre><code>from astropy.io import fits

hdulist = fits.open('MAST_2022-08-18T22_14_30.604Z/HST/J90702010/j90702xvq_flc.fits')

hdulist.info()
&lt;long output as you had above&gt;
# Copy header and data
header = hdulist['SCI', 1].header
data = hdulist['SCI', 1].data
# Construct new HDU and HDUList
hdu = fits.PrimaryHDU(data, header)
new_hdulist = fits.HDUList([hdu,])
# Write out
new_hdulist.writeto(&quot;xvq_sci1.fits&quot;, checksum=True, overwrite=True)
# Dump new hdulist info
new_hdulist.info()

Filename: (No file associated with this HDUList)
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  SCI           1 PrimaryHDU     242   (4096, 2048)   float32  
</code></pre>
<p>This will now be readable by <code>STIFF</code>:</p>
<pre><code>$ stiff xvq_sci1.fits 

&gt; WARNING: stiff.conf not found, using internal defaults

----- STIFF 2.4.0 started on 2022-08-18 at 15:50:47 with 8 threads

&gt; BigTIFF support is: ON (libTIFF V4.0)

----- Inputs:
xvq_sci1.fits: &quot;no ident&quot;  4096x2048   32 bits (floats)
Background level: 94.8088     Min level: 91.9828     Max level: 2917.95   

----- Output:
stiff.tif:   4096x2048    8  bits (integers) gamma: x1.00  compression: LZW 

&gt; All done (in 0.6 s: 3370.7 lines/s , 13.8 Mpixels/s)
<span class="math-container">```</span>
</code></pre>

CC BY-SA 4.0
2022-08-19T03:04:53.910Z
Thanks a lot! And I found another method to use ds9. In rgb frame, I can add three images as three different colors. I just mention it for beginners.
BAO
CC BY-SA 4.0
2022-08-19T09:46:28.180Z
Hello, I have a question. Is the stiff can use the color more than three? If it can not use more than three colors, is there any method to stack images more than three with colors? Because the reason why I want to use stiff is that I want to check my result from tweakreg and astrodrizzle by stacking it. If I can stack more than three images with color, It is more convenient for checking the results.
BAO
CC BY-SA 4.0
2022-08-19T15:15:37.620Z
`STIFF` is part of the AstrOmatic suite of software so the "obvious" recommendation will be to use [SWarp](https://www.astromatic.net/software/swarp/) from the same suite to stack the images for the individual color channels. Stacking several images will be a good way to get rid of the large number of cosmic ray hits that are going to present in HST data.
astrosnapper
CC BY-SA 4.0
2022-08-21T10:19:25.920Z
Thank you for your comment, and sorry for my ambiguous question. I just want to check where each fits files take a space in final drizzle file(or final swarp file). So if the final image composed of 5 fits files, than there are 10 chips in ACS/WFC. This is my question: Is there any tool which can stack this 10 image as all different color?
BAO
CC BY-SA 4.0
2022-08-23T21:25:40.500Z
I don't know of any; most software or tutorials for making color images from FITS assume 3 channels of RGB, occasionally a 4th Luminance channel. `ds9` can tile multiple images (if you had *9* this would make a nice 3x3 grid...) which could then be colorized ? Otherwise I think you would need some custom Python code - pick 10 spaced samples from a matplotlib [colormap](https://matplotlib.org/stable/gallery/color/colormap_reference.html) for plotting using the [WCS info](https://docs.astropy.org/en/stable/visualization/wcsaxes/index.html) ?
astrosnapper
CC BY-SA 4.0
2022-09-03T11:20:40.250Z
Oh, I didn't think about using matplotlib. Thank you for your comment.
BAO
CC BY-SA 4.0
2022-08-18T23:04:57.013Z
2022-08-18T23:04:57.013Z
astrosnapper
<p>I try to use &quot;stiff&quot; library now.</p>
<p>This library is from <a href="https://www.astromatic.net/software/stiff/" rel="nofollow noreferrer">astromatic.net</a></p>
<p>I follow the <a href="https://manualzilla.com/doc/6909201/user-s-guide---astromatic.net?page=24" rel="nofollow noreferrer">tutorial</a>'s example1(page 18), but It is not worked.</p>
<pre><code>#tutorial1
stiff -IMAGE TYPE TIFF-PYRAMID d1 i.fits d1 r.fits d1 g.fits -GAMMA FAC 1.1
-COLOUR SAT 2.2 -MAX TYPE MANUAL -MAX LEVEL 550,350,160 -MIN LEVEL 0.00001
-SATUR LEVEL 10000 -COMPRESSION TYPE DEFLATE -OUTFILE NAME d1 gri.ptif
</code></pre>
<p>There is also really simply <a href="https://manpages.ubuntu.com/manpages/kinetic/man1/stiff.1.html" rel="nofollow noreferrer">tutorial for Ubuntu</a></p>
<pre><code>#really simple tutorial
       stiff &lt;fits_image1&gt; [&lt;fits_image2&gt; &lt;fits_image3&gt;]
              [-c &lt;Configuration_file&gt;] [-&lt;keyword&gt; &lt;value&gt; ...]

</code></pre>
<p>So I just put code like below.</p>
<pre><code>stiff j90702xvq_flc.fits
</code></pre>
<p>But this error message came out</p>
<pre><code>----- STIFF 2.4.0 started on 2022-08-14 at 20:23:10 with 16 threads

&gt; BigTIFF support is: ON (libTIFF V4.4)

----- Inputs:
&gt; Examining File j90702xvq_flc.fits
&gt; *Error*: no 2D FITS data in j90702xvq_flc.fits

</code></pre>
<p>So, I try to cut the fits file using below code</p>
<pre><code>from astropy.io import fits
xvq_sci1 = fits.open(&quot;j90702xvq_flc.fits&quot;)[&quot;SCI&quot;,1]
xvq_sci1.writeto(&quot;xvq_sci1.fits&quot;)
</code></pre>
<p>And, I try again like below.</p>
<pre><code>stiff xvq_sci1.fits
</code></pre>
<p>But it show the same error message..</p>
<pre><code>----- STIFF 2.4.0 started on 2022-08-14 at 20:28:59 with 16 threads

&gt; BigTIFF support is: ON (libTIFF V4.4)

----- Inputs:
&gt; Examining File xvq_sci1.fits
&gt; *Error*: no 2D FITS data in xvq_sci1.fits
</code></pre>
<p>How can I use this library?</p>
<p>============added the fits file's info ===============</p>
<pre><code># xvq_sci1.fits is j90702xvq_flc.fits[1]
Filename: j90702xvq_flc.fits
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  PRIMARY       1 PrimaryHDU     291   ()
  1  SCI           1 ImageHDU       242   (4096, 2048)   float32
  2  ERR           1 ImageHDU        53   (4096, 2048)   float32
  3  DQ            1 ImageHDU        45   (4096, 2048)   int16
  4  SCI           2 ImageHDU       240   (4096, 2048)   float32
  5  ERR           2 ImageHDU        53   (4096, 2048)   float32
  6  DQ            2 ImageHDU        45   (4096, 2048)   int16
  7  D2IMARR       1 ImageHDU        16   (64, 32)   float32
  8  D2IMARR       2 ImageHDU        16   (64, 32)   float32
  9  D2IMARR       3 ImageHDU        16   (64, 32)   float32
 10  D2IMARR       4 ImageHDU        16   (64, 32)   float32
 11  WCSDVARR      1 ImageHDU        16   (64, 32)   float32
 12  WCSDVARR      2 ImageHDU        16   (64, 32)   float32
 13  WCSDVARR      3 ImageHDU        16   (64, 32)   float32
 14  WCSDVARR      4 ImageHDU        16   (64, 32)   float32
 15  HDRLET        1 NonstandardExtHDU     18   (8640,)
 16  HDRLET        2 NonstandardExtHDU     26   (112320,)
 17  WCSCORR       1 BinTableHDU     59   14R x 24C   [40A, I, A, 24A, 24A, 24A, 24A, D, D, D, D, D, D, D, D, 24A, 24A, D, D, D, D, J, 40A, 128A]
 18  HDRLET       18 NonstandardExtHDU     26   (112320,)
 19  HDRLET        4 NonstandardExtHDU     26   (112320,)
</code></pre>
<p>It's header is below</p>
<pre><code>XTENSION= 'IMAGE   '           / IMAGE extension
BITPIX  =                  -32 / number of bits per data pixel
NAXIS   =                    2 / number of data axes
NAXIS1  =                 4096 / length of data axis 1
NAXIS2  =                 2048 / length of data axis 2
PCOUNT  =                    0 / required keyword; must = 0
GCOUNT  =                    1 / required keyword; must = 1
ORIGIN  = 'HSTIO/CFITSIO March 2010' / FITS file originator
DATE    = '2022-06-07' / date this file was written (yyyy-mm-dd)
INHERIT =                    T / inherit the primary header
EXTNAME = 'SCI     '           / extension name
EXTVER  =                    1 / extension version number
ROOTNAME= 'j90702xvq                         ' / rootname of the observation set
EXPNAME = 'j90702xvq                ' / exposure identifier
BUNIT   = 'ELECTRONS'          / brightness units

              / WFC CCD CHIP IDENTIFICATION

CCDCHIP =                    2 / CCD chip (1 or 2)

              / World Coordinate System and Related Parameters

WCSAXES =                    2 / Number of coordinate axes
CRPIX1  =   2.048000000000E+03 / Pixel coordinate of reference point
CRPIX2  =   1.024000000000E+03 / Pixel coordinate of reference point
CRVAL1  =      104.66499909807 / [deg] Coordinate value at reference point
CRVAL2  =     -55.954761771866 / [deg] Coordinate value at reference point
CTYPE1  = 'RA---TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CTYPE2  = 'DEC--TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CD1_1   = -4.4785510975087E-06 / partial of first axis coordinate w.r.t. x
CD1_2   = -1.3503023575236E-05 / partial of first axis coordinate w.r.t. y
CD2_1   = -1.3102837874246E-05 / partial of second axis coordinate w.r.t. x
CD2_2   =  3.5992906396453E-06 / partial of second axis coordinate w.r.t. y
LTV1    =        0.0000000E+00 / offset in X to subsection start
LTV2    =        0.0000000E+00 / offset in Y to subsection start
RAW_LTV1=                 24.0 / original offset in X to subsection start
RAW_LTV2=                  0.0 / original offset in Y to subsection start
LTM1_1  =                  1.0 / reciprocal of sampling rate in X
LTM2_2  =                  1.0 / reciprocal of sampling rate in Y
ORIENTAT=   -75.07458718991118
RA_APER =   1.046346868685E+02 / RA of aperture reference position
DEC_APER=  -5.595013378909E+01 / Declination of aperture reference position
PA_APER =             -75.2776 / Position Angle of reference aperture center (de
VAFACTOR=   1.000018616289E+00 / velocity aberration plate scale factor

              / READOUT DEFINITION PARAMETERS

CENTERA1=                 2073 / subarray axis1 center pt in unbinned dect. pix
CENTERA2=                 1035 / subarray axis2 center pt in unbinned dect. pix
SIZAXIS1=                 4096 / subarray axis1 size in unbinned detector pixels
SIZAXIS2=                 2048 / subarray axis2 size in unbinned detector pixels
BINAXIS1=                    1 / axis1 data bin size in unbinned detector pixels
BINAXIS2=                    1 / axis2 data bin size in unbinned detector pixels

              / PHOTOMETRY KEYWORDS

PHOTMODE= 'ACS WFC1 F606W MJD#53299.8176' / obser
PHOTFLAM=        7.7709941E-20 / inverse sensitivity, ergs/cm2/Ang/electron
PHOTZPT =       -2.1100000E+01 / ST magnitude zero point
PHOTPLAM=        5.9197700E+03 / Pivot wavelength (Angstroms)
PHOTBW  =        6.7245856E+02 / RMS bandwidth of filter plus detector

              / REPEATED EXPOSURES INFO

NCOMBINE=                    1 / number of image sets combined during CR rejecti

              / DATA PACKET INFORMATION

FILLCNT =                    0 / number of segments containing fill
ERRCNT  =                    0 / number of segments containing errors
PODPSFF =                    F / podps fill present (T/F)
STDCFFF =                    F / science telemetry fill data present (T=1/F=0)
STDCFFP = '0x5569'             / science telemetry fill pattern (hex)

              / ON-BOARD COMPRESSION INFORMATION

WFCMPRSD=                    F / was WFC data compressed? (T/F)
CBLKSIZ =                    0 / size of compression block in 2-byte words
LOSTPIX =                    0 / #pixels lost due to buffer overflow
COMPTYP = 'None    '           / compression type performed (Partial/Full/None)

              / IMAGE STATISTICS AND DATA QUALITY FLAGS

NGOODPIX=              8184177 / number of good pixels
SDQFLAGS=                31743 / serious data quality flags
GOODMIN =       -1.6824574E+02 / minimum value of good pixels
GOODMAX =        6.3376828E+04 / maximum value of good pixels
GOODMEAN=        1.0438736E+02 / mean value of good pixels
SOFTERRS=                    0 / number of soft error pixels (DQF=1)
SNRMIN  =       -1.6364522E+00 / minimum signal to noise of good pixels
SNRMAX  =        2.0984293E+02 / maximum signal to noise of good pixels
SNRMEAN =        8.8789072E+00 / mean value of signal to noise of good pixels
MEANDARK=        2.5262651E+00 / average of the dark values subtracted
MEANBLEV=        2.4926467E+03 / average of all bias levels subtracted
MEANFLSH=             0.000000 / Mean number of counts in post flash exposure
RADESYS = 'FK5     '           / Equatorial coordinate system
S_REGION= 'POLYGON ICRS 104.70620243734865 -55.93154845738201 &amp;'
CONTINUE  '104.6568582007068 -55.92418430227887 104.62405936693303 &amp;'
CONTINUE  '-55.97783370398132 104.67346579957582 -55.98521095833816 '
OCX10   =          0.001966255 / original linear term from IDCTAB
OCX11   =  0.04982607143461245 / original linear term from IDCTAB
OCY10   =          0.050268501 / original linear term from IDCTAB
OCY11   =  0.00148317144398288 / original linear term from IDCTAB
IDCSCALE=                 0.05 / pixel scale from the IDCTAB reference file
IDCTHETA=                  0.0 / orientation of detector's Y-axis w.r.t. V3 axis
IDCXREF =               2048.0 / reference pixel location in X
IDCYREF =               1024.0 / reference pixel location in Y
IDCV2REF=              257.198 / reference pixel's V2 position
IDCV3REF=            302.54099 / reference pixel's V3 position
D2IMERR1=  0.04100000113248825 / Maximum error of D2IM correction for axis 1
D2IMDIS1= 'Lookup  '           / Detector to image correction type
D2IM1   = 'EXTVER: 1' / Version number of WCSDVARR extension
D2IM1   = 'NAXES: 2' / Number of independent variables in D2IM function
D2IM1   = 'AXIS.1: 1' / Axis number of the 1st variable in a D2IM function
D2IM1   = 'AXIS.2: 2' / Axis number of the 2nd variable in a D2IM function
D2IMERR2=  0.06199999898672104 / Maximum error of D2IM correction for axis 2
D2IMDIS2= 'Lookup  '           / Detector to image correction type
D2IM2   = 'EXTVER: 2' / Version number of WCSDVARR extension
D2IM2   = 'NAXES: 2' / Number of independent variables in D2IM function
D2IM2   = 'AXIS.1: 1' / Axis number of the 1st variable in a D2IM function
D2IM2   = 'AXIS.2: 2' / Axis number of the 2nd variable in a D2IM function
D2IMEXT = 'jref<span class="math-container">$4bb15371j_d2i.fits'
WCSNAMEO= 'OPUS    '           / Coordinate system title
WCSAXESO=                    2 / Number of coordinate axes
CRPIX1O =               2048.0 / Pixel coordinate of reference point
CRPIX2O =               1024.0 / Pixel coordinate of reference point
CUNIT1O = 'deg'                / Units of coordinate increment and value
CUNIT2O = 'deg'                / Units of coordinate increment and value
CTYPE1O = 'RA---TAN'           / Right ascension, gnomonic projection
CTYPE2O = 'DEC--TAN'           / Declination, gnomonic projection
CRVAL1O =       104.6651715164 / [deg] Coordinate value at reference point
CRVAL2O =      -55.95469315841 / [deg] Coordinate value at reference point
RADESYSO= 'FK5'                / Equatorial coordinate system
CD1_1O  =         -4.47984E-06 / partial of first axis coordinate w.r.t. x
CD1_2O  =          -1.3504E-05 / partial of first axis coordinate w.r.t. y
CD2_1O  =         -1.31028E-05 / partial of second axis coordinate w.r.t. x
CD2_2O  =          3.60073E-06 / partial of second axis coordinate w.r.t. y
TDDALPHA=  / time-dependent y-skew offset (pre-2014 IDCTAB)
TDDBETA =  / time-dependent y-skew rate (pre-2014 IDCTAB)
TDD_CTA =  / time-dependent x-skew rate (&gt;2015 IDCTAB)
TDD_CTB =     1.8248490745E-06 / time-dependent y-skew rate (&gt;2015 IDCTAB)
TDD_CYA =  / time-dependent y-skew offset (2014 IDCTAB)
TDD_CYB =  / time-dependent y-scale rate (&gt;2015 IDCTAB)
TDD_CXA =  / time-dependent x-skew offset (2014 IDCTAB)
TDD_CXB =    -2.5860963562E-07 / time-dependent x-scale rate (&gt;2015 IDCTAB)
IDCTAB  = 'jref$</span>4bb1536oj_idc.fits'
A_ORDER =                    5 / SIP polynomial order, axis 0, detector to sky
B_ORDER =                    5 / SIP polynomial order, axis 1, detector to sky
A_0_2   = 2.15429726056098E-06 / SIP distortion coefficient
B_0_2   = -7.2087131099993E-06 / SIP distortion coefficient
A_1_1   =  -5.200804069539E-06 / SIP distortion coefficient
B_1_1   = 6.18797413675992E-06 / SIP distortion coefficient
A_2_0   = 8.54623663797755E-06 / SIP distortion coefficient
B_2_0   = -1.7415783919032E-06 / SIP distortion coefficient
A_0_3   = 1.05547285171463E-11 / SIP distortion coefficient
B_0_3   = -4.1850073213712E-10 / SIP distortion coefficient
A_1_2   = -5.2140913070077E-10 / SIP distortion coefficient
B_1_2   = -7.4497665381203E-11 / SIP distortion coefficient
A_2_1   = -2.1990075526867E-11 / SIP distortion coefficient
B_2_1   =  -5.214892910359E-10 / SIP distortion coefficient
A_3_0   =  -4.914710867438E-10 / SIP distortion coefficient
B_3_0   = 1.05135639143121E-10 / SIP distortion coefficient
A_0_4   = 2.48323580000051E-14 / SIP distortion coefficient
B_0_4   = -1.5640821560849E-14 / SIP distortion coefficient
A_1_3   = -1.5550422384845E-14 / SIP distortion coefficient
B_1_3   = 4.89582815336137E-15 / SIP distortion coefficient
A_2_2   = 3.77465928223555E-14 / SIP distortion coefficient
B_2_2   = -3.9374053914632E-14 / SIP distortion coefficient
A_3_1   = 8.74830212986719E-16 / SIP distortion coefficient
B_3_1   = -2.4138281583179E-15 / SIP distortion coefficient
A_4_0   = 2.46228167669957E-14 / SIP distortion coefficient
B_4_0   = -1.8450418258925E-14 / SIP distortion coefficient
A_0_5   = 6.69704732099372E-19 / SIP distortion coefficient
B_0_5   = 2.79449775248818E-18 / SIP distortion coefficient
A_1_4   = -6.0833475781275E-18 / SIP distortion coefficient
B_1_4   = 1.46879784104105E-17 / SIP distortion coefficient
A_2_3   = -2.6932582793839E-19 / SIP distortion coefficient
B_2_3   = 1.62257588260141E-18 / SIP distortion coefficient
A_3_2   = 3.33589661711327E-18 / SIP distortion coefficient
B_3_2   = -4.9160619694192E-19 / SIP distortion coefficient
A_4_1   = -4.1307895599613E-18 / SIP distortion coefficient
B_4_1   = 3.10870954987174E-18 / SIP distortion coefficient
A_5_0   = 3.58237797214263E-18 / SIP distortion coefficient
B_5_0   =  -4.029904944049E-18 / SIP distortion coefficient
WCSNAME = 'IDC_4bb1536oj-FIT_REL_GAIAeDR3' / Coordinate system title
CPERR1  =  0.02237761206924915 / Maximum error of NPOL correction for axis 1
CPDIS1  = 'Lookup  '           / Prior distortion function type
DP1     = 'EXTVER: 1' / Version number of WCSDVARR extension
DP1     = 'NAXES: 2' / Number of independent variables in CPDIS function
DP1     = 'AXIS.1: 1' / Axis number of the 1st variable in a CPDIS function
DP1     = 'AXIS.2: 2' / Axis number of the 2nd variable in a CPDIS function
CPERR2  =  0.01327170338481665 / Maximum error of NPOL correction for axis 2
CPDIS2  = 'Lookup  '           / Prior distortion function type
DP2     = 'EXTVER: 2' / Version number of WCSDVARR extension
DP2     = 'NAXES: 2' / Number of independent variables in CPDIS function
DP2     = 'AXIS.1: 1' / Axis number of the 1st variable in a CPDIS function
DP2     = 'AXIS.2: 2' / Axis number of the 2nd variable in a CPDIS function
NPOLEXT = 'jref$4bb1536ej_npl.fits'
MDRIZSKY=    93.53200531005859 / Sky value computed by AstroDrizzle
CUNIT1  = 'deg'                / Units of coordinate increment and value
CUNIT2  = 'deg'                / Units of coordinate increment and value
WCSNAMEA= 'IDC_4bb1536oj'      / Coordinate system title
WCSAXESA=                    2 / Number of coordinate axes
CRPIX1A =               2048.0 / Pixel coordinate of reference point
CRPIX2A =               1024.0 / Pixel coordinate of reference point
CUNIT1A = 'deg'                / Units of coordinate increment and value
CUNIT2A = 'deg'                / Units of coordinate increment and value
CTYPE1A = 'RA---TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CTYPE2A = 'DEC--TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CRVAL1A =       104.6651715164 / [deg] Coordinate value at reference point
CRVAL2A =      -55.95469315841 / [deg] Coordinate value at reference point
RADESYSA= 'FK5'                / Equatorial coordinate system
CD1_1A  = -4.4782271150184E-06 / partial of first axis coordinate w.r.t. x
CD1_2A  = -1.3503017310676E-05 / partial of first axis coordinate w.r.t. y
CD2_1A  = -1.3102819997905E-05 / partial of second axis coordinate w.r.t. x
CD2_2A  =  3.5989798532426E-06 / partial of second axis coordinate w.r.t. y
WCSTYPE = 'undistorted a posteriori solution relatively aligned to GAIAEDR3'
WCSNAMEB= 'IDC_4bb1536oj-GSC240-1' / Coordinate system title
WCSAXESB=                    2 / Number of coordinate axes
CRPIX1B =               2048.0 / Pixel coordinate of reference point
CRPIX2B =               1024.0 / Pixel coordinate of reference point
CUNIT1B = 'deg'                / Units of coordinate increment and value
CUNIT2B = 'deg'                / Units of coordinate increment and value
CTYPE1B = 'RA---TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CTYPE2B = 'DEC--TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CRVAL1B =      104.66507450074 / [deg] Coordinate value at reference point
CRVAL2B =       -55.9546202279 / [deg] Coordinate value at reference point
MJDREF  =                  0.0 / [d] MJD of fiducial time
RADESYSB= 'FK5'                / Equatorial coordinate system
CD1_1B  = -4.4782454992572E-06 / partial of first axis coordinate w.r.t. x
CD1_2B  = -1.3503012265713E-05 / partial of first axis coordinate w.r.t. y
CD2_1B  = -1.3102813715263E-05 / partial of second axis coordinate w.r.t. x
CD2_2B  =  3.5989988058199E-06 / partial of second axis coordinate w.r.t. y
WCSTYPEB= 'undistorted a priori solution based on GSC240'
HDRNAMEB= 'j90702xvq_flc_409e04_hlet.fits'
RMS_RA  =    18.43313508005606 / RMS in RA of WCS fit(mas)
RMS_DEC =    12.03670629057446 / RMS in Dec of WCS fit(mas)
CRDER1  = 0.005120315300015573
CRDER2  = 0.003343529525159573
NMATCHES=                   55
FITGEOM = 'rscale  '
HDRNAME = 'j90702xvq_flc_IDC_4bb1536oj-FIT_REL_GAIAeDR3-hlet.fits'
WCSTYPEA= 'undistorted not aligned'
WCSTYPEO= 'pipeline default not aligned'
</code></pre>

CC BY-SA 4.0
2022-08-14T12:29:13.010Z
What's in the two files that end in .fits? Double check to make sure they actually exist
Barry Carter
CC BY-SA 4.0
2022-08-14T15:39:51.090Z
It can be only received one file(grey scale) or three file(rgb). Even if I put three file, the result is same.
BAO
CC BY-SA 4.0
2022-08-15T23:07:42.960Z
Can you modify your astropy code fragment to do `xvq_sci = fits.open("j90702xvq_flc.fits") ; print(xvq_sci.info()) ; xvq_sci1 = xvq_sci["SCI",1]` We need to see what the structure of the FITS file (and `HDUList.info()` is a good way to find out) is before we can diagnose what's not working.
astrosnapper
CC BY-SA 4.0
2022-08-17T07:08:00.330Z
@astrosnapper I edited it. Thank you for your comment
BAO
<observational-astronomy><fits>
How can I use the "stiff"(the library from this site; astromatic.net). I can not escape from the error[*Error*: no 2D FITS data in <MY FITS FILE>]
BAO
# How can I use the "stiff"(the library from this site; astromatic.net). I can not escape from the error[*Error*: no 2D FITS data in <MY FITS FILE>]

(Asked by: username_0 on 2022-08-14)

I try to use "stiff" library now.
This library is from astromatic.net
I follow the tutorial's example1(page 18), but It is not worked.
#tutorial1
stiff -IMAGE TYPE TIFF-PYRAMID d1 i.fits d1 r.fits d1 g.fits -GAMMA FAC 1.1
-COLOUR SAT 2.2 -MAX TYPE MANUAL -MAX LEVEL 550,350,160 -MIN LEVEL 0.00001
-SATUR LEVEL 10000 -COMPRESSION TYPE DEFLATE -OUTFILE NAME d1 gri.ptif

There is also really simply tutorial for Ubuntu
#really simple tutorial
       stiff  [ ]
              [-c ] [-  ...]


So I just put code like below.
stiff j90702xvq_flc.fits

But this error message came out
----- STIFF 2.4.0 started on 2022-08-14 at 20:23:10 with 16 threads

> BigTIFF support is: ON (libTIFF V4.4)

----- Inputs:
> Examining File j90702xvq_flc.fits
> *Error*: no 2D FITS data in j90702xvq_flc.fits


So, I try to cut the fits file using below code
from astropy.io import fits
xvq_sci1 = fits.open("j90702xvq_flc.fits")["SCI",1]
xvq_sci1.writeto("xvq_sci1.fits")

And, I try again like below.
stiff xvq_sci1.fits

But it show the same error message..
----- STIFF 2.4.0 started on 2022-08-14 at 20:28:59 with 16 threads

> BigTIFF support is: ON (libTIFF V4.4)

----- Inputs:
> Examining File xvq_sci1.fits
> *Error*: no 2D FITS data in xvq_sci1.fits

How can I use this library?
============added the fits file's info ===============
# xvq_sci1.fits is j90702xvq_flc.fits[1]
Filename: j90702xvq_flc.fits
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  PRIMARY       1 PrimaryHDU     291   ()
  1  SCI           1 ImageHDU       242   (4096, 2048)   float32
  2  ERR           1 ImageHDU        53   (4096, 2048)   float32
  3  DQ            1 ImageHDU        45   (4096, 2048)   int16
  4  SCI           2 ImageHDU       240   (4096, 2048)   float32
  5  ERR           2 ImageHDU        53   (4096, 2048)   float32
  6  DQ            2 ImageHDU        45   (4096, 2048)   int16
  7  D2IMARR       1 ImageHDU        16   (64, 32)   float32
  8  D2IMARR       2 ImageHDU        16   (64, 32)   float32
  9  D2IMARR       3 ImageHDU        16   (64, 32)   float32
 10  D2IMARR       4 ImageHDU        16   (64, 32)   float32
 11  WCSDVARR      1 ImageHDU        16   (64, 32)   float32
 12  WCSDVARR      2 ImageHDU        16   (64, 32)   float32
 13  WCSDVARR      3 ImageHDU        16   (64, 32)   float32
 14  WCSDVARR      4 ImageHDU        16   (64, 32)   float32
 15  HDRLET        1 NonstandardExtHDU     18   (8640,)
 16  HDRLET        2 NonstandardExtHDU     26   (112320,)
 17  WCSCORR       1 BinTableHDU     59   14R x 24C   [40A, I, A, 24A, 24A, 24A, 24A, D, D, D, D, D, D, D, D, 24A, 24A, D, D, D, D, J, 40A, 128A]
 18  HDRLET       18 NonstandardExtHDU     26   (112320,)
 19  HDRLET        4 NonstandardExtHDU     26   (112320,)

It's header is below
XTENSION= 'IMAGE   '           / IMAGE extension
BITPIX  =                  -32 / number of bits per data pixel
NAXIS   =                    2 / number of data axes
NAXIS1  =                 4096 / length of data axis 1
NAXIS2  =                 2048 / length of data axis 2
PCOUNT  =                    0 / required keyword; must = 0
GCOUNT  =                    1 / required keyword; must = 1
ORIGIN  = 'HSTIO/CFITSIO March 2010' / FITS file originator
DATE    = '2022-06-07' / date this file was written (yyyy-mm-dd)
INHERIT =                    T / inherit the primary header
EXTNAME = 'SCI     '           / extension name
EXTVER  =                    1 / extension version number
ROOTNAME= 'j90702xvq                         ' / rootname of the observation set
EXPNAME = 'j90702xvq                ' / exposure identifier
BUNIT   = 'ELECTRONS'          / brightness units

              / WFC CCD CHIP IDENTIFICATION

CCDCHIP =                    2 / CCD chip (1 or 2)

              / World Coordinate System and Related Parameters

WCSAXES =                    2 / Number of coordinate axes
CRPIX1  =   2.048000000000E+03 / Pixel coordinate of reference point
CRPIX2  =   1.024000000000E+03 / Pixel coordinate of reference point
CRVAL1  =      104.66499909807 / [deg] Coordinate value at reference point
CRVAL2  =     -55.954761771866 / [deg] Coordinate value at reference point
CTYPE1  = 'RA---TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CTYPE2  = 'DEC--TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CD1_1   = -4.4785510975087E-06 / partial of first axis coordinate w.r.t. x
CD1_2   = -1.3503023575236E-05 / partial of first axis coordinate w.r.t. y
CD2_1   = -1.3102837874246E-05 / partial of second axis coordinate w.r.t. x
CD2_2   =  3.5992906396453E-06 / partial of second axis coordinate w.r.t. y
LTV1    =        0.0000000E+00 / offset in X to subsection start
LTV2    =        0.0000000E+00 / offset in Y to subsection start
RAW_LTV1=                 24.0 / original offset in X to subsection start
RAW_LTV2=                  0.0 / original offset in Y to subsection start
LTM1_1  =                  1.0 / reciprocal of sampling rate in X
LTM2_2  =                  1.0 / reciprocal of sampling rate in Y
ORIENTAT=   -75.07458718991118
RA_APER =   1.046346868685E+02 / RA of aperture reference position
DEC_APER=  -5.595013378909E+01 / Declination of aperture reference position
PA_APER =             -75.2776 / Position Angle of reference aperture center (de
VAFACTOR=   1.000018616289E+00 / velocity aberration plate scale factor

              / READOUT DEFINITION PARAMETERS

CENTERA1=                 2073 / subarray axis1 center pt in unbinned dect. pix
CENTERA2=                 1035 / subarray axis2 center pt in unbinned dect. pix
SIZAXIS1=                 4096 / subarray axis1 size in unbinned detector pixels
SIZAXIS2=                 2048 / subarray axis2 size in unbinned detector pixels
BINAXIS1=                    1 / axis1 data bin size in unbinned detector pixels
BINAXIS2=                    1 / axis2 data bin size in unbinned detector pixels

              / PHOTOMETRY KEYWORDS

PHOTMODE= 'ACS WFC1 F606W MJD#53299.8176' / obser
PHOTFLAM=        7.7709941E-20 / inverse sensitivity, ergs/cm2/Ang/electron
PHOTZPT =       -2.1100000E+01 / ST magnitude zero point
PHOTPLAM=        5.9197700E+03 / Pivot wavelength (Angstroms)
PHOTBW  =        6.7245856E+02 / RMS bandwidth of filter plus detector

              / REPEATED EXPOSURES INFO

NCOMBINE=                    1 / number of image sets combined during CR rejecti

              / DATA PACKET INFORMATION

FILLCNT =                    0 / number of segments containing fill
ERRCNT  =                    0 / number of segments containing errors
PODPSFF =                    F / podps fill present (T/F)
STDCFFF =                    F / science telemetry fill data present (T=1/F=0)
STDCFFP = '0x5569'             / science telemetry fill pattern (hex)

              / ON-BOARD COMPRESSION INFORMATION

WFCMPRSD=                    F / was WFC data compressed? (T/F)
CBLKSIZ =                    0 / size of compression block in 2-byte words
LOSTPIX =                    0 / #pixels lost due to buffer overflow
COMPTYP = 'None    '           / compression type performed (Partial/Full/None)

              / IMAGE STATISTICS AND DATA QUALITY FLAGS

NGOODPIX=              8184177 / number of good pixels
SDQFLAGS=                31743 / serious data quality flags
GOODMIN =       -1.6824574E+02 / minimum value of good pixels
GOODMAX =        6.3376828E+04 / maximum value of good pixels
GOODMEAN=        1.0438736E+02 / mean value of good pixels
SOFTERRS=                    0 / number of soft error pixels (DQF=1)
SNRMIN  =       -1.6364522E+00 / minimum signal to noise of good pixels
SNRMAX  =        2.0984293E+02 / maximum signal to noise of good pixels
SNRMEAN =        8.8789072E+00 / mean value of signal to noise of good pixels
MEANDARK=        2.5262651E+00 / average of the dark values subtracted
MEANBLEV=        2.4926467E+03 / average of all bias levels subtracted
MEANFLSH=             0.000000 / Mean number of counts in post flash exposure
RADESYS = 'FK5     '           / Equatorial coordinate system
S_REGION= 'POLYGON ICRS 104.70620243734865 -55.93154845738201 &'
CONTINUE  '104.6568582007068 -55.92418430227887 104.62405936693303 &'
CONTINUE  '-55.97783370398132 104.67346579957582 -55.98521095833816 '
OCX10   =          0.001966255 / original linear term from IDCTAB
OCX11   =  0.04982607143461245 / original linear term from IDCTAB
OCY10   =          0.050268501 / original linear term from IDCTAB
OCY11   =  0.00148317144398288 / original linear term from IDCTAB
IDCSCALE=                 0.05 / pixel scale from the IDCTAB reference file
IDCTHETA=                  0.0 / orientation of detector's Y-axis w.r.t. V3 axis
IDCXREF =               2048.0 / reference pixel location in X
IDCYREF =               1024.0 / reference pixel location in Y
IDCV2REF=              257.198 / reference pixel's V2 position
IDCV3REF=            302.54099 / reference pixel's V3 position
D2IMERR1=  0.04100000113248825 / Maximum error of D2IM correction for axis 1
D2IMDIS1= 'Lookup  '           / Detector to image correction type
D2IM1   = 'EXTVER: 1' / Version number of WCSDVARR extension
D2IM1   = 'NAXES: 2' / Number of independent variables in D2IM function
D2IM1   = 'AXIS.1: 1' / Axis number of the 1st variable in a D2IM function
D2IM1   = 'AXIS.2: 2' / Axis number of the 2nd variable in a D2IM function
D2IMERR2=  0.06199999898672104 / Maximum error of D2IM correction for axis 2
D2IMDIS2= 'Lookup  '           / Detector to image correction type
D2IM2   = 'EXTVER: 2' / Version number of WCSDVARR extension
D2IM2   = 'NAXES: 2' / Number of independent variables in D2IM function
D2IM2   = 'AXIS.1: 1' / Axis number of the 1st variable in a D2IM function
D2IM2   = 'AXIS.2: 2' / Axis number of the 2nd variable in a D2IM function
D2IMEXT = 'jref$4bb15371j_d2i.fits'
WCSNAMEO= 'OPUS    '           / Coordinate system title
WCSAXESO=                    2 / Number of coordinate axes
CRPIX1O =               2048.0 / Pixel coordinate of reference point
CRPIX2O =               1024.0 / Pixel coordinate of reference point
CUNIT1O = 'deg'                / Units of coordinate increment and value
CUNIT2O = 'deg'                / Units of coordinate increment and value
CTYPE1O = 'RA---TAN'           / Right ascension, gnomonic projection
CTYPE2O = 'DEC--TAN'           / Declination, gnomonic projection
CRVAL1O =       104.6651715164 / [deg] Coordinate value at reference point
CRVAL2O =      -55.95469315841 / [deg] Coordinate value at reference point
RADESYSO= 'FK5'                / Equatorial coordinate system
CD1_1O  =         -4.47984E-06 / partial of first axis coordinate w.r.t. x
CD1_2O  =          -1.3504E-05 / partial of first axis coordinate w.r.t. y
CD2_1O  =         -1.31028E-05 / partial of second axis coordinate w.r.t. x
CD2_2O  =          3.60073E-06 / partial of second axis coordinate w.r.t. y
TDDALPHA=  / time-dependent y-skew offset (pre-2014 IDCTAB)
TDDBETA =  / time-dependent y-skew rate (pre-2014 IDCTAB)
TDD_CTA =  / time-dependent x-skew rate (>2015 IDCTAB)
TDD_CTB =     1.8248490745E-06 / time-dependent y-skew rate (>2015 IDCTAB)
TDD_CYA =  / time-dependent y-skew offset (2014 IDCTAB)
TDD_CYB =  / time-dependent y-scale rate (>2015 IDCTAB)
TDD_CXA =  / time-dependent x-skew offset (2014 IDCTAB)
TDD_CXB =    -2.5860963562E-07 / time-dependent x-scale rate (>2015 IDCTAB)
IDCTAB  = 'jref$4bb1536oj_idc.fits'
A_ORDER =                    5 / SIP polynomial order, axis 0, detector to sky
B_ORDER =                    5 / SIP polynomial order, axis 1, detector to sky
A_0_2   = 2.15429726056098E-06 / SIP distortion coefficient
B_0_2   = -7.2087131099993E-06 / SIP distortion coefficient
A_1_1   =  -5.200804069539E-06 / SIP distortion coefficient
B_1_1   = 6.18797413675992E-06 / SIP distortion coefficient
A_2_0   = 8.54623663797755E-06 / SIP distortion coefficient
B_2_0   = -1.7415783919032E-06 / SIP distortion coefficient
A_0_3   = 1.05547285171463E-11 / SIP distortion coefficient
B_0_3   = -4.1850073213712E-10 / SIP distortion coefficient
A_1_2   = -5.2140913070077E-10 / SIP distortion coefficient
B_1_2   = -7.4497665381203E-11 / SIP distortion coefficient
A_2_1   = -2.1990075526867E-11 / SIP distortion coefficient
B_2_1   =  -5.214892910359E-10 / SIP distortion coefficient
A_3_0   =  -4.914710867438E-10 / SIP distortion coefficient
B_3_0   = 1.05135639143121E-10 / SIP distortion coefficient
A_0_4   = 2.48323580000051E-14 / SIP distortion coefficient
B_0_4   = -1.5640821560849E-14 / SIP distortion coefficient
A_1_3   = -1.5550422384845E-14 / SIP distortion coefficient
B_1_3   = 4.89582815336137E-15 / SIP distortion coefficient
A_2_2   = 3.77465928223555E-14 / SIP distortion coefficient
B_2_2   = -3.9374053914632E-14 / SIP distortion coefficient
A_3_1   = 8.74830212986719E-16 / SIP distortion coefficient
B_3_1   = -2.4138281583179E-15 / SIP distortion coefficient
A_4_0   = 2.46228167669957E-14 / SIP distortion coefficient
B_4_0   = -1.8450418258925E-14 / SIP distortion coefficient
A_0_5   = 6.69704732099372E-19 / SIP distortion coefficient
B_0_5   = 2.79449775248818E-18 / SIP distortion coefficient
A_1_4   = -6.0833475781275E-18 / SIP distortion coefficient
B_1_4   = 1.46879784104105E-17 / SIP distortion coefficient
A_2_3   = -2.6932582793839E-19 / SIP distortion coefficient
B_2_3   = 1.62257588260141E-18 / SIP distortion coefficient
A_3_2   = 3.33589661711327E-18 / SIP distortion coefficient
B_3_2   = -4.9160619694192E-19 / SIP distortion coefficient
A_4_1   = -4.1307895599613E-18 / SIP distortion coefficient
B_4_1   = 3.10870954987174E-18 / SIP distortion coefficient
A_5_0   = 3.58237797214263E-18 / SIP distortion coefficient
B_5_0   =  -4.029904944049E-18 / SIP distortion coefficient
WCSNAME = 'IDC_4bb1536oj-FIT_REL_GAIAeDR3' / Coordinate system title
CPERR1  =  0.02237761206924915 / Maximum error of NPOL correction for axis 1
CPDIS1  = 'Lookup  '           / Prior distortion function type
DP1     = 'EXTVER: 1' / Version number of WCSDVARR extension
DP1     = 'NAXES: 2' / Number of independent variables in CPDIS function
DP1     = 'AXIS.1: 1' / Axis number of the 1st variable in a CPDIS function
DP1     = 'AXIS.2: 2' / Axis number of the 2nd variable in a CPDIS function
CPERR2  =  0.01327170338481665 / Maximum error of NPOL correction for axis 2
CPDIS2  = 'Lookup  '           / Prior distortion function type
DP2     = 'EXTVER: 2' / Version number of WCSDVARR extension
DP2     = 'NAXES: 2' / Number of independent variables in CPDIS function
DP2     = 'AXIS.1: 1' / Axis number of the 1st variable in a CPDIS function
DP2     = 'AXIS.2: 2' / Axis number of the 2nd variable in a CPDIS function
NPOLEXT = 'jref$4bb1536ej_npl.fits'
MDRIZSKY=    93.53200531005859 / Sky value computed by AstroDrizzle
CUNIT1  = 'deg'                / Units of coordinate increment and value
CUNIT2  = 'deg'                / Units of coordinate increment and value
WCSNAMEA= 'IDC_4bb1536oj'      / Coordinate system title
WCSAXESA=                    2 / Number of coordinate axes
CRPIX1A =               2048.0 / Pixel coordinate of reference point
CRPIX2A =               1024.0 / Pixel coordinate of reference point
CUNIT1A = 'deg'                / Units of coordinate increment and value
CUNIT2A = 'deg'                / Units of coordinate increment and value
CTYPE1A = 'RA---TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CTYPE2A = 'DEC--TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CRVAL1A =       104.6651715164 / [deg] Coordinate value at reference point
CRVAL2A =      -55.95469315841 / [deg] Coordinate value at reference point
RADESYSA= 'FK5'                / Equatorial coordinate system
CD1_1A  = -4.4782271150184E-06 / partial of first axis coordinate w.r.t. x
CD1_2A  = -1.3503017310676E-05 / partial of first axis coordinate w.r.t. y
CD2_1A  = -1.3102819997905E-05 / partial of second axis coordinate w.r.t. x
CD2_2A  =  3.5989798532426E-06 / partial of second axis coordinate w.r.t. y
WCSTYPE = 'undistorted a posteriori solution relatively aligned to GAIAEDR3'
WCSNAMEB= 'IDC_4bb1536oj-GSC240-1' / Coordinate system title
WCSAXESB=                    2 / Number of coordinate axes
CRPIX1B =               2048.0 / Pixel coordinate of reference point
CRPIX2B =               1024.0 / Pixel coordinate of reference point
CUNIT1B = 'deg'                / Units of coordinate increment and value
CUNIT2B = 'deg'                / Units of coordinate increment and value
CTYPE1B = 'RA---TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CTYPE2B = 'DEC--TAN-SIP'       / TAN (gnomonic) projection + SIP distortions
CRVAL1B =      104.66507450074 / [deg] Coordinate value at reference point
CRVAL2B =       -55.9546202279 / [deg] Coordinate value at reference point
MJDREF  =                  0.0 / [d] MJD of fiducial time
RADESYSB= 'FK5'                / Equatorial coordinate system
CD1_1B  = -4.4782454992572E-06 / partial of first axis coordinate w.r.t. x
CD1_2B  = -1.3503012265713E-05 / partial of first axis coordinate w.r.t. y
CD2_1B  = -1.3102813715263E-05 / partial of second axis coordinate w.r.t. x
CD2_2B  =  3.5989988058199E-06 / partial of second axis coordinate w.r.t. y
WCSTYPEB= 'undistorted a priori solution based on GSC240'
HDRNAMEB= 'j90702xvq_flc_409e04_hlet.fits'
RMS_RA  =    18.43313508005606 / RMS in RA of WCS fit(mas)
RMS_DEC =    12.03670629057446 / RMS in Dec of WCS fit(mas)
CRDER1  = 0.005120315300015573
CRDER2  = 0.003343529525159573
NMATCHES=                   55
FITGEOM = 'rscale  '
HDRNAME = 'j90702xvq_flc_IDC_4bb1536oj-FIT_REL_GAIAeDR3-hlet.fits'
WCSTYPEA= 'undistorted not aligned'
WCSTYPEO= 'pipeline default not aligned'

**Tags:** observational-astronomy, fits

> **Comments:**
> **username_1**: What's in the two files that end in .fits? Double check to make sure they actually exist  
> **username_0**: It can be only received one file(grey scale) or three file(rgb). Even if I put three file, the result is same.  
> **username_2**: Can you modify your astropy code fragment to do `xvq_sci = fits.open("j90702xvq_flc.fits") ; print(xvq_sci.info()) ; xvq_sci1 = xvq_sci["SCI",1]` We need to see what the structure of the FITS file (and `HDUList.info()` is a good way to find out) is before we can diagnose what's not working.  
> **username_0**: @username_2 I edited it. Thank you for your comment  

---

## 1 answers

### Answer by username_2 on 2022-08-18. Score: 1 | Accepted answer

STIFF needs the data in a single HDU without extensions. I was able to fetch the data from the MAST query form by selecting IMAGE types, ACS as the only instrument, F606W as the filter and searching around (RA,Dec)= (104.66499909807, -55.954761771866). Once you've got the data down, you need to split out the SCI(ence) extensions (there are two, one for each chip in the ACS Wide Field Camera(WFC)) from the (complicated) Multi-Extension FITS (as you have tried). The trick is to write it into a new empty PrimaryHDU:
from astropy.io import fits

hdulist = fits.open('MAST_2022-08-18T22_14_30.604Z/HST/J90702010/j90702xvq_flc.fits')

hdulist.info()

# Copy header and data
header = hdulist['SCI', 1].header
data = hdulist['SCI', 1].data
# Construct new HDU and HDUList
hdu = fits.PrimaryHDU(data, header)
new_hdulist = fits.HDUList([hdu,])
# Write out
new_hdulist.writeto("xvq_sci1.fits", checksum=True, overwrite=True)
# Dump new hdulist info
new_hdulist.info()

Filename: (No file associated with this HDUList)
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  SCI           1 PrimaryHDU     242   (4096, 2048)   float32  

This will now be readable by STIFF:
$ stiff xvq_sci1.fits 

> WARNING: stiff.conf not found, using internal defaults

----- STIFF 2.4.0 started on 2022-08-18 at 15:50:47 with 8 threads

> BigTIFF support is: ON (libTIFF V4.0)

----- Inputs:
xvq_sci1.fits: "no ident"  4096x2048   32 bits (floats)
Background level: 94.8088     Min level: 91.9828     Max level: 2917.95   

----- Output:
stiff.tif:   4096x2048    8  bits (integers) gamma: x1.00  compression: LZW 

> All done (in 0.6 s: 3370.7 lines/s , 13.8 Mpixels/s)
```

> **Comments:**
> **username_0**: Thanks a lot! And I found another method to use ds9. In rgb frame, I can add three images as three different colors. I just mention it for beginners.  
> **username_0**: Hello, I have a question. Is the stiff can use the color more than three? If it can not use more than three colors, is there any method to stack images more than three with colors? Because the reason why I want to use stiff is that I want to check my result from tweakreg and astrodrizzle by stacking it. If I can stack more than three images with color, It is more convenient for checking the results.  
> **username_2**: `STIFF` is part of the AstrOmatic suite of software so the "obvious" recommendation will be to use [SWarp](https://www.astromatic.net/software/swarp/) from the same suite to stack the images for the individual color channels. Stacking several images will be a good way to get rid of the large number of cosmic ray hits that are going to present in HST data.  
> **username_0**: Thank you for your comment, and sorry for my ambiguous question. I just want to check where each fits files take a space in final drizzle file(or final swarp file). So if the final image composed of 5 fits files, than there are 10 chips in ACS/WFC. This is my question: Is there any tool which can stack this 10 image as all different color?  
> **username_2**: I don't know of any; most software or tutorials for making color images from FITS assume 3 channels of RGB, occasionally a 4th Luminance channel. `ds9` can tile multiple images (if you had *9* this would make a nice 3x3 grid...) which could then be colorized ? Otherwise I think you would need some custom Python code - pick 10 spaced samples from a matplotlib [colormap](https://matplotlib.org/stable/gallery/color/colormap_reference.html) for plotting using the [WCS info](https://docs.astropy.org/en/stable/visualization/wcsaxes/index.html) ?  
> **username_0**: Oh, I didn't think about using matplotlib. Thank you for your comment.  

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