diff --git a/datasets/raise/extract_noise.py b/datasets/raise/extract_noise.py
index f99174e..9ff8d12 100755
--- a/datasets/raise/extract_noise.py
+++ b/datasets/raise/extract_noise.py
@@ -53,9 +53,8 @@ if type_ is not None:
 minColor = None
 maxColor = None
 
-# `color` is the actual color to estimate PRNU with.
-def treatImage(imageFileName, computeExtremes = False, color = None):
-    global mean, numberOfImagesInMean, minColor, maxColor
+def getImageNpArray(imageFileName, computeExtremes, color):
+    global minColor, maxColor
     if raiseNotFlatFields:
         imageFileName = imageFileName.replace('.png', '.NEF')
         imageFilePath = f'{imagesFolderPath}/nef/{imageFileName}'
@@ -100,7 +99,14 @@ def treatImage(imageFileName, computeExtremes = False, color = None):
     else:
         imagePil = Image.open(imageFilePath)
         imageNpArray = img_as_float(np.array(imagePil))
-    # Could make not `.nef` compatible.
+    return imageNpArray
+
+# `color` is the actual color to estimate PRNU with.
+def treatImage(imageFileName, computeExtremes = False, color = None):
+    global mean, numberOfImagesInMean
+    imageNpArray = getImageNpArray(imageFileName, computeExtremes, color)
+    if imageNpArray is None:
+        return
     match denoiser:
         case 'wavelet':
             imageDenoisedNpArray = denoise(imageNpArray, rescale_sigma=True)