diff --git a/datasets/raise/split_and_compare_prnus_of_subgroups.py b/datasets/raise/split_and_compare_prnus_of_subgroups.py
index f35296b..c3c2bac 100644
--- a/datasets/raise/split_and_compare_prnus_of_subgroups.py
+++ b/datasets/raise/split_and_compare_prnus_of_subgroups.py
@@ -7,19 +7,20 @@ import sys
 
 sys.path.insert(0, '../../algorithms/image_utils/')
 
-from image_utils import showImageWithMatplotlib
+from image_utils import showImageWithMatplotlib, toPilImage
 
 sys.path.insert(0, '../../algorithms/distance/')
 
 from rms_diff import rmsDiffNumpy
 
-NUMBER_OF_SUBGROUPS = 2
+NUMBER_OF_SUBGROUPS = 1
 
 IMAGES_FOLDER = 'flat-field/TIF'
 imagesFileNames = os.listdir(IMAGES_FOLDER)
 numberOfImagesPerSubgroup = len(imagesFileNames) // NUMBER_OF_SUBGROUPS
 
-numberOfImagesThresholds = range(1, numberOfImagesPerSubgroup + 1)
+# 1
+numberOfImagesThresholds = range(numberOfImagesPerSubgroup, numberOfImagesPerSubgroup + 1)
 
 # Assume random image order to not introduce a bias.
 subgroupsPrnuEstimatesNpArray = []
@@ -36,6 +37,7 @@ for subgroupIndex in range(NUMBER_OF_SUBGROUPS):
     # Not efficient mean computation.
     for numberOfImagesIndex, numberOfImages in enumerate(numberOfImagesThresholds):
         subgroupPrnuEstimateNpArray += [np.array(imagesPrnuEstimateNpArray[:numberOfImages]).mean(axis = 0)]
+        toPilImage(subgroupPrnuEstimateNpArray[-1]).save('prnu.png')
     subgroupsPrnuEstimatesNpArray += [subgroupPrnuEstimateNpArray]
 
 rmss = []