https://free-astro.org/index.php?title=Siril:supported_FITS&feed=atom&action=history Siril:supported FITS - Revision history 2024-03-28T16:21:38Z Revision history for this page on the wiki MediaWiki 1.40.0 https://free-astro.org/index.php?title=Siril:supported_FITS&diff=8461&oldid=prev Vincent: deprecation 2023-09-13T15:35:42Z <p>deprecation</p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:35, 13 September 2023</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;span style="color: #ff0090; font-weight: bold; text-align: center; margin: 2em; font-size: 125%;">This page is now deprecated. Please refer to the new documentation [https://siril.readthedocs.io/en/stable/file-formats/FITS.html here] and [https://siril.readthedocs.io/en/stable/Sequences.html#a-single-fits-file here].&lt;/span></ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Supported FITS files by [[Siril]]=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Supported FITS files by [[Siril]]=</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> </table> Vincent https://free-astro.org/index.php?title=Siril:supported_FITS&diff=7586&oldid=prev Vincent: Update for 0.99.x 2021-02-22T23:42:21Z <p>Update for 0.99.x</p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 23:42, 22 February 2021</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Supported FITS files by [[Siril]]=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Supported FITS files by [[Siril]]=</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In versions 0.9.x, the native image file format of [[Siril]] <del style="font-weight: bold; text-decoration: none;">is </del>unsigned 16-bit FITS (USHORT), one or three layers only, <del style="font-weight: bold; text-decoration: none;">ordered </del>bottom-up. <del style="font-weight: bold; text-decoration: none;">This is </del>the format <del style="font-weight: bold; text-decoration: none;">in which other images </del>are <del style="font-weight: bold; text-decoration: none;">converted </del>to <del style="font-weight: bold; text-decoration: none;">when using </del>the <del style="font-weight: bold; text-decoration: none;">conversion tab</del>, the <del style="font-weight: bold; text-decoration: none;">internal representation of images loaded in  Siril </del>and <del style="font-weight: bold; text-decoration: none;">which </del>it <del style="font-weight: bold; text-decoration: none;">processes</del>, the format in <del style="font-weight: bold; text-decoration: none;">which processing results </del>are <del style="font-weight: bold; text-decoration: none;">saved and </del>the format <del style="font-weight: bold; text-decoration: none;">used in </del>FITS <del style="font-weight: bold; text-decoration: none;">sequence export</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In versions 0.9.x, the native image file format of [[Siril]] <ins style="font-weight: bold; text-decoration: none;">was </ins>unsigned 16-bit FITS (USHORT), one or three layers only, <ins style="font-weight: bold; text-decoration: none;">with data [[Siril:FITS_orientation|stored </ins>bottom-up<ins style="font-weight: bold; text-decoration: none;">]]</ins>.</div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Since the introduction of </ins>the <ins style="font-weight: bold; text-decoration: none;">0.99.x series, a second native image file </ins>format <ins style="font-weight: bold; text-decoration: none;">has been introduced, the 32-bit floating point FITS (FLOAT), normalized to 1, so with values between 0 and 1, one or three layers only and with data [[Siril:FITS_orientation|stored bottom-up]] as well. It was a widely requested feature, and its main purposes </ins>are to <ins style="font-weight: bold; text-decoration: none;">increase the precision that results from image processing and to support negative values on bias/dark subtraction.</ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">This new 32 bits format became </ins>the <ins style="font-weight: bold; text-decoration: none;">default format since its introduction</ins>, <ins style="font-weight: bold; text-decoration: none;">but since it doubles </ins>the <ins style="font-weight: bold; text-decoration: none;">requirements for available memory and disk space </ins>and <ins style="font-weight: bold; text-decoration: none;">slows the processing down, </ins>it <ins style="font-weight: bold; text-decoration: none;">can be disabled in the preferences. In that case</ins>, the <ins style="font-weight: bold; text-decoration: none;">behaviour is the same as in older 0.9.x versions.</ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">The 32 bits </ins>format <ins style="font-weight: bold; text-decoration: none;">is not used </ins>in <ins style="font-weight: bold; text-decoration: none;">conversion when not needed. In general, acquired images </ins>are <ins style="font-weight: bold; text-decoration: none;">8 or 16 bits deep, so for these, Siril still uses </ins>the <ins style="font-weight: bold; text-decoration: none;">16 bits </ins>format<ins style="font-weight: bold; text-decoration: none;">. For preprocessing, the images are then converted to 32 bits.</ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Siril can also use </ins>FITS <ins style="font-weight: bold; text-decoration: none;">compression. It is disabled by default, see the preferences to enable it. It saves disk space, but requires more processing power to compress images when writing them and to decompress them when reading them back</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Bitpix: pixel precision==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Bitpix: pixel precision==</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">But </del>Siril can <del style="font-weight: bold; text-decoration: none;">also </del>work with other FITS formats, meaning that it can load, display and process them just like the file <del style="font-weight: bold; text-decoration: none;">format </del>above, but <del style="font-weight: bold; text-decoration: none;">the internal representation, results and exports </del>will <del style="font-weight: bold; text-decoration: none;">still </del>be <del style="font-weight: bold; text-decoration: none;">the native FITS USHORT format, starting with version 0.9.9</del>:</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Siril can work with other FITS formats, meaning that it can load, display and process them just like the file <ins style="font-weight: bold; text-decoration: none;">formats </ins>above, but <ins style="font-weight: bold; text-decoration: none;">they </ins>will be <ins style="font-weight: bold; text-decoration: none;">converted to either formats on loading</ins>:</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* 8-bit integers per channel: the images are converted to 16 bits in memory, no problem</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* 8-bit integers per channel: the images are converted to 16 bits <ins style="font-weight: bold; text-decoration: none;">(USHORT) </ins>in memory, no problem</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 16-bit integers per channel: the signed SHORT images are converted to unsigned short, and no problem either for 15 bits formats. USHORT is in fact [https://heasarc.gsfc.nasa.gov/docs/software/fitsio/c/c_user/node23.html stored as SHORT] with a 2^15 offset.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 16-bit integers per channel: the signed SHORT images are converted to unsigned short, and no problem either for 15 bits formats. USHORT is in fact [https://heasarc.gsfc.nasa.gov/docs/software/fitsio/c/c_user/node23.html stored as SHORT] with a 2^15 offset.</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit integers per channel: <del style="font-weight: bold; text-decoration: none;">only </del>the <del style="font-weight: bold; text-decoration: none;">16 most significant bits are kept, equivalent </del>to <del style="font-weight: bold; text-decoration: none;">dividing by 65536, in consequence some precision is lost. If in </del>the 32-bit <del style="font-weight: bold; text-decoration: none;">integers contain small data</del>, <del style="font-weight: bold; text-decoration: none;">like values between 0 </del>and <del style="font-weight: bold; text-decoration: none;">65535</del>, <del style="font-weight: bold; text-decoration: none;">the result will be between 0 </del>and <del style="font-weight: bold; text-decoration: none;">1 as integer</del>, <del style="font-weight: bold; text-decoration: none;">in other words useless. We may add in </del>the <del style="font-weight: bold; text-decoration: none;">future a way to specify how </del>the <del style="font-weight: bold; text-decoration: none;">conversion </del>is <del style="font-weight: bold; text-decoration: none;">made</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit integers per channel: the <ins style="font-weight: bold; text-decoration: none;">image is converted </ins>to the <ins style="font-weight: bold; text-decoration: none;">floating point </ins>32-bit <ins style="font-weight: bold; text-decoration: none;">format. Data is normalised with the maximum value</ins>, and <ins style="font-weight: bold; text-decoration: none;">the minimum value is used as an offset. This is fine to use a single image, but not for a sequence</ins>, <ins style="font-weight: bold; text-decoration: none;">as min </ins>and <ins style="font-weight: bold; text-decoration: none;">max value change among frames</ins>, the <ins style="font-weight: bold; text-decoration: none;">consistency of </ins>the <ins style="font-weight: bold; text-decoration: none;">data </ins>is <ins style="font-weight: bold; text-decoration: none;">not preserved</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 64-bit integers per channel: not currently supported, it would almost be sure to give unusable data.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 64-bit integers per channel: not currently supported, it would almost be sure to give unusable data.</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit and 64-bit floating point numbers: <del style="font-weight: bold; text-decoration: none;">they are </del>loaded <del style="font-weight: bold; text-decoration: none;">by multiplying their value with 2^16</del>, <del style="font-weight: bold; text-decoration: none;">so </del>if <del style="font-weight: bold; text-decoration: none;">they are stored with values between 0 and </del>1 <del style="font-weight: bold; text-decoration: none;">it's usable with some precision loss. If they are stored with values between arbitrary DATAMIN and DATAMAX FITS header keywords values</del>, <del style="font-weight: bold; text-decoration: none;">this will not be usable</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit and 64-bit floating point numbers: <ins style="font-weight: bold; text-decoration: none;">the image is </ins>loaded <ins style="font-weight: bold; text-decoration: none;">as Siril's 32-bit image format</ins>, <ins style="font-weight: bold; text-decoration: none;">but </ins>if <ins style="font-weight: bold; text-decoration: none;">the input data is not normalized to </ins>1, <ins style="font-weight: bold; text-decoration: none;">the data is divided by 65535</ins>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''Siril 1.0 will switch to a floating point representation of data''', providing better precision and support of most formats.</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">==FITS cube==</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">==</del>FITS <del style="font-weight: bold; text-decoration: none;">groups==</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Since the 0.99.x versions, Siril provides another way to save a sequence of images with the </ins>FITS <ins style="font-weight: bold; text-decoration: none;">format: the ''FITS cube'', or fitseq as we call it sometimes; it is a single FITS file containing several FITS images. Siril only uses these files to store its own sequences, meaning that all images inside the file must have the same type of data, or the same dimensions and pixel format. The same FITS formats are supported as for regular FITS images.</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">Siril is currently unable to load most </del>FITS <del style="font-weight: bold; text-decoration: none;">images from professional observatories because they contain </del>a lot of metadata and the image data is not registered as the primary content of the file. <del style="font-weight: bold; text-decoration: none;">It is in </del>a <del style="font-weight: bold; text-decoration: none;">subgroup of data</del>, <del style="font-weight: bold; text-decoration: none;">but Siril reads only the first group</del>. <del style="font-weight: bold; text-decoration: none;">Maybe in the future we </del>will <del style="font-weight: bold; text-decoration: none;">handle these formats</del>, <del style="font-weight: bold; text-decoration: none;">but this and the precision of versions 0.9 make Siril '''unsuitable for professional use'''</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Professional observatories provide data in form of a </ins>FITS <ins style="font-weight: bold; text-decoration: none;">cube, with </ins>a lot of metadata and <ins style="font-weight: bold; text-decoration: none;">various types of data. Often, </ins>the image data is not registered as the primary content of the file. <ins style="font-weight: bold; text-decoration: none;">Siril may be able to open the file as </ins>a <ins style="font-weight: bold; text-decoration: none;">sequence</ins>, <ins style="font-weight: bold; text-decoration: none;">and may be able to display an image from it</ins>. <ins style="font-weight: bold; text-decoration: none;">Using a sequence of these files </ins>will <ins style="font-weight: bold; text-decoration: none;">not work</ins>, <ins style="font-weight: bold; text-decoration: none;">it may only be possible to display or extract an image from such a file</ins>.</div></td></tr> </table> Vincent https://free-astro.org/index.php?title=Siril:supported_FITS&diff=5772&oldid=prev Vincent: /* Supported FITS files by Siril */ small fix 2018-02-21T00:50:19Z <p><span dir="auto"><span class="autocomment">Supported FITS files by Siril: </span> small fix</span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 00:50, 21 February 2018</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Supported FITS files by [[Siril]]=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Supported FITS files by [[Siril]]=</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In versions 0.9.x, the native image file format of [[Siril]] is unsigned 16-bit FITS (USHORT), one or three layers only. This is the format in which other images are converted to when using the conversion tab, the internal representation of images loaded in  Siril and which it processes, the format in which processing results are saved and the format used in FITS sequence export.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In versions 0.9.x, the native image file format of [[Siril]] is unsigned 16-bit FITS (USHORT), one or three layers only<ins style="font-weight: bold; text-decoration: none;">, ordered bottom-up</ins>. This is the format in which other images are converted to when using the conversion tab, the internal representation of images loaded in  Siril and which it processes, the format in which processing results are saved and the format used in FITS sequence export.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Bitpix: pixel precision==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Bitpix: pixel precision==</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l8">Line 8:</td> <td colspan="2" class="diff-lineno">Line 8:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 8-bit integers per channel: the images are converted to 16 bits in memory, no problem</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 8-bit integers per channel: the images are converted to 16 bits in memory, no problem</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 16-bit integers per channel: the signed SHORT images are converted to unsigned short, and no problem either for 15 bits formats. USHORT is in fact [https://heasarc.gsfc.nasa.gov/docs/software/fitsio/c/c_user/node23.html stored as SHORT] with a 2^15 offset.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 16-bit integers per channel: the signed SHORT images are converted to unsigned short, and no problem either for 15 bits formats. USHORT is in fact [https://heasarc.gsfc.nasa.gov/docs/software/fitsio/c/c_user/node23.html stored as SHORT] with a 2^15 offset.</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit integers per channel: only the 16 most significant bits are kept, some precision is lost. If in the 32-bit integers contain small data, like values between 0 and 65535, the result will be between 0 and 1 as integer, in other words useless. We may add in the future a way to specify how the conversion is made.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit integers per channel: only the 16 most significant bits are kept, <ins style="font-weight: bold; text-decoration: none;">equivalent to dividing by 65536, in consequence </ins>some precision is lost. If in the 32-bit integers contain small data, like values between 0 and 65535, the result will be between 0 and 1 as integer, in other words useless. We may add in the future a way to specify how the conversion is made.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 64-bit integers per channel: not currently supported, it would almost be sure to give unusable data.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 64-bit integers per channel: not currently supported, it would almost be sure to give unusable data.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit and 64-bit floating point numbers: they are loaded by multiplying their value with 2^16, so if they are stored with values between 0 and 1 it&#039;s usable with some precision loss. If they are stored with values between arbitrary DATAMIN and DATAMAX FITS header keywords values, this will not be usable.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* 32-bit and 64-bit floating point numbers: they are loaded by multiplying their value with 2^16, so if they are stored with values between 0 and 1 it&#039;s usable with some precision loss. If they are stored with values between arbitrary DATAMIN and DATAMAX FITS header keywords values, this will not be usable.</div></td></tr> </table> Vincent https://free-astro.org/index.php?title=Siril:supported_FITS&diff=5770&oldid=prev Vincent: listing 0.9.9 formats 2018-02-20T23:32:14Z <p>listing 0.9.9 formats</p> <p><b>New page</b></p><div>=Supported FITS files by [[Siril]]=<br /> <br /> In versions 0.9.x, the native image file format of [[Siril]] is unsigned 16-bit FITS (USHORT), one or three layers only. This is the format in which other images are converted to when using the conversion tab, the internal representation of images loaded in Siril and which it processes, the format in which processing results are saved and the format used in FITS sequence export.<br /> <br /> ==Bitpix: pixel precision==<br /> <br /> But Siril can also work with other FITS formats, meaning that it can load, display and process them just like the file format above, but the internal representation, results and exports will still be the native FITS USHORT format, starting with version 0.9.9:<br /> * 8-bit integers per channel: the images are converted to 16 bits in memory, no problem<br /> * 16-bit integers per channel: the signed SHORT images are converted to unsigned short, and no problem either for 15 bits formats. USHORT is in fact [https://heasarc.gsfc.nasa.gov/docs/software/fitsio/c/c_user/node23.html stored as SHORT] with a 2^15 offset.<br /> * 32-bit integers per channel: only the 16 most significant bits are kept, some precision is lost. If in the 32-bit integers contain small data, like values between 0 and 65535, the result will be between 0 and 1 as integer, in other words useless. We may add in the future a way to specify how the conversion is made.<br /> * 64-bit integers per channel: not currently supported, it would almost be sure to give unusable data.<br /> * 32-bit and 64-bit floating point numbers: they are loaded by multiplying their value with 2^16, so if they are stored with values between 0 and 1 it&#039;s usable with some precision loss. If they are stored with values between arbitrary DATAMIN and DATAMAX FITS header keywords values, this will not be usable.<br /> <br /> &#039;&#039;&#039;Siril 1.0 will switch to a floating point representation of data&#039;&#039;&#039;, providing better precision and support of most formats.<br /> <br /> ==FITS groups==<br /> <br /> Siril is currently unable to load most FITS images from professional observatories because they contain a lot of metadata and the image data is not registered as the primary content of the file. It is in a subgroup of data, but Siril reads only the first group. Maybe in the future we will handle these formats, but this and the precision of versions 0.9 make Siril &#039;&#039;&#039;unsuitable for professional use&#039;&#039;&#039;.</div> Vincent