Read FITS files.

Backend Library: Astropy


To use this plugin you have to install its backend:

pip install imageio[fits]

Flexible Image Transport System (FITS) is an open standard defining a digital file format useful for storage, transmission and processing of scientific and other images. FITS is the most commonly used digital file format in astronomy.



If the file name is a URL, is used to open the file. This specifies whether or not to save the file locally in Astropy’s download cache (default: True).


Interpret signed integer data where BZERO is the central value and BSCALE == 1 as unsigned integer data. For example, int16 data with BZERO = 32768 and BSCALE = 1 would be treated as uint16 data.

Note, for backward compatibility, the kwarg uint16 may be used instead. The kwarg was renamed when support was added for integers of any size.


Do not issue an exception when opening a file that is missing an END card in the last header.

checksumbool or str

If True, verifies that both DATASUM and CHECKSUM card values (when present in the HDU header) match the header and data of all HDU’s in the file. Updates to a file that already has a checksum will preserve and update the existing checksums unless this argument is given a value of ‘remove’, in which case the CHECKSUM and DATASUM values are not checked, and are removed when saving changes to the file.

disable_image_compressionbool, optional

If True, treats compressed image HDU’s like normal binary table HDU’s.


If True, image data is not scaled using BSCALE/BZERO values when read.


If True, the BLANK keyword is ignored if present.


If True, when saving changes to a file that contained scaled image data, restore the data to the original type and reapply the original BSCALE/BZERO values. This could lead to loss of accuracy if scaling back to integer values after performing floating point operations on the data.