diff --git a/shapepipe/modules/uncompress_fits_image_package/__init__.py b/shapepipe/modules/uncompress_fits_image_package/__init__.py
new file mode 100644
index 000000000..0ca86a56d
--- /dev/null
+++ b/shapepipe/modules/uncompress_fits_image_package/__init__.py
@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+
+"""UNCOMRESS FITS
+
+This module uncompress fits images and save them on a single hdu fits.
+
+:Author: Axel Guinot, Martin Kilbinger <martin.kilbinger@cea.fr>
+
+:Date: 2020
+
+:Package: ShapePipe
+
+"""
+
+__all__ = ['uncompress']
diff --git a/shapepipe/modules/uncompress_fits_image_package/uncompress.py b/shapepipe/modules/uncompress_fits_image_package/uncompress.py
new file mode 100644
index 000000000..6ca3e806e
--- /dev/null
+++ b/shapepipe/modules/uncompress_fits_image_package/uncompress.py
@@ -0,0 +1,72 @@
+# -*- coding: utf-8 -*-
+
+"""UNCOMRESS FITS
+
+This module uncompress fits images and save them on a single hdu fits.
+
+:Author: Axel Guinot, Martin Kilbinger <martin.kilbinger@cea.fr>
+
+:Date: 2020
+
+:Package: ShapePipe
+
+"""
+
+from astropy.io import fits
+
+
+class Uncompress(object):
+    """Uncompress
+
+    This class handles the uncompress process of compressed FITS files.
+
+    Parameters
+    ----------
+    input_file_list : array of string
+        input files
+    output_pattern_list : array of string
+        output file pattern
+    output_dir : string
+        output directory
+    file_number_string : string
+        image numbering (pipeline ID string)
+    data_hdu : int
+        input HDU number
+    """
+
+    def __init__(
+        self,
+        input_file_list,
+        output_pattern_list,
+        output_dir,
+        file_number_string,
+        data_hdu
+    ):
+
+        self._input_file_list = input_file_list
+        self._output_pattern_list = output_pattern_list
+        self._output_dir = output_dir
+        self._file_number_string = file_number_string
+        self._data_hdu = data_hdu
+
+    def process(self):
+        """Process
+
+        Main function to process uncompress.
+        """
+
+        # Go through input list
+        for i in range(len(self._input_file_list)):
+
+            # Get data and header
+            data = fits.getdata(self._input_file_list[i], self._data_hdu)
+            header = fits.getheader(self._input_file_list[i], self._data_hdu)
+
+            # Create and write new FITS file with that HDU only
+            hdu = fits.PrimaryHDU(data, header)
+            hdul = fits.HDUList([hdu])
+            hdul.writeto(
+                f'{self._output_dir}/'
+                + f'{self._output_pattern_list[i]}'
+                + f'{self._file_number_string}.fits'
+            )
diff --git a/shapepipe/modules/uncompress_fits_image_runner.py b/shapepipe/modules/uncompress_fits_image_runner.py
index fbbd5a509..22cb91597 100644
--- a/shapepipe/modules/uncompress_fits_image_runner.py
+++ b/shapepipe/modules/uncompress_fits_image_runner.py
@@ -1,46 +1,61 @@
 # -*- coding: utf-8 -*-
 
-"""UNCOMPRESS_FITS_IMAGE_RUNNER
+"""UNCOMPRESS FITS IMAGE RUNNER
 
+Module runner for ``uncompress_fits_image_runner``
 This module uncompress fits images and save them on a single hdu fits.
 
-:Author: Axel Guinot
+:Author: Axel Guinot, Martin Kilbinger <martin.kilbinger@cea.fr>
 
-"""
-
-from shapepipe.modules.module_decorator import module_runner
+:Date: 2020
 
-from astropy.io import fits
+:Package: ShapePipe
 
+"""
 
-@module_runner(version='1.0',
-               file_pattern=['image'],
-               file_ext=['.fits'],
-               numbering_scheme='_0')
-def uncompress_fits_image_runner(input_file_list, run_dirs, file_number_string,
-                                 config, w_log):
-
+from shapepipe.modules.module_decorator import module_runner
+import shapepipe.modules.uncompress_fits_image_package.uncompress as uz
+
+
+@module_runner(
+    version='1.1',
+    file_pattern=['image'],
+    file_ext=['.fits'],
+    numbering_scheme='_0'
+)
+def uncompress_fits_image_runner(
+    input_file_list,
+    run_dirs,
+    file_number_string,
+    config,
+    w_log
+):
+
+    # Get output patterns
     output_pattern_list = config.getlist('UNCOMPRESS_FITS_IMAGE_RUNNER', 'OUTPUT_PATTERN')
 
+    # Get HDU number
     if config.has_option('UNCOMPRESS_FITS_IMAGE_RUNNER', 'HDU_DATA'):
         data_hdu = config.getint("UNCOMPRESS_FITS_IMAGE_RUNNER", "HDU_DATA")
     else:
         data_hdu = 0
 
+    # Check consistency of input and output list lengths
     if len(input_file_list) != len(output_pattern_list):
-        raise ValueError('Lists INPUT_PATH ({}) and OUTPUT_PATTERN ({}) '
-                         'need to be of equal length.'
-                         ''.format(len(input_file_list),
-                                   len(output_pattern_list)))
-
-    # Read data from input list files
-    for i in range(len(input_file_list)):
-        data = fits.getdata(input_file_list[i], data_hdu)
-        header = fits.getheader(input_file_list[i], data_hdu)
-
-        # Create and write new FITS file with that HDU only
-        hdu = fits.PrimaryHDU(data, header)
-        hdul = fits.HDUList([hdu])
-        hdul.writeto('{}/{}{}.fits'.format(run_dirs['output'], output_pattern_list[i], file_number_string))
+        raise ValueError(
+            f'Lists INPUT_PATH ({len(input_file_list)})'
+            + f' and OUTPUT_PATTERN ({len(output_pattern_list)})'
+            + 'need to be of equal length.'
+        )
+
+    # Create instance of uncompress
+    uz_inst = uz.Uncompress(
+        input_file_list,
+        output_pattern_list,
+        run_dirs['output'],
+        file_number_string,
+        data_hdu)
+
+    uz_inst.process()
 
     return None, None