diff --git a/algorithms/image_utils/image_utils.py b/algorithms/image_utils/image_utils.py
index aa87568..7a0e495 100644
--- a/algorithms/image_utils/image_utils.py
+++ b/algorithms/image_utils/image_utils.py
@@ -5,10 +5,11 @@ from matplotlib import pyplot as plt
 def randomGaussianImage(scale, size):
     return np.random.normal(loc = 0, scale = scale, size = size)
 
-def showImageWithMatplotlib(npArray, title = None):
+# `cmap` source: https://matplotlib.org/3.8.0/api/_as_gen/matplotlib.pyplot.imshow.html
+def showImageWithMatplotlib(npArray, title = None, cmap = 'viridis'):
     if title is not None:
         plt.title(title)
-    plt.imshow(npArray)
+    plt.imshow(npArray, cmap = cmap)
     plt.show()
 
 def toPilImage(npArray):
diff --git a/datasets/noise_free_test_images/estimate_prnu.py b/datasets/noise_free_test_images/estimate_prnu.py
index d6b4618..bc29312 100644
--- a/datasets/noise_free_test_images/estimate_prnu.py
+++ b/datasets/noise_free_test_images/estimate_prnu.py
@@ -62,5 +62,12 @@ for imageName in os.listdir(datasetPath):
 
 cameraPrnuEstimateNpArray = np.array(imagesPrnuEstimateNpArray).mean(axis = 0)
 rms = rmsDiffNumpy(cameraPrnuEstimateNpArray, prnuNpArray, True)
-showImageWithMatplotlib(cameraPrnuEstimateNpArray, f'Camera PRNU estimate\nRMS with actual one: {rmsDiffNumpy(cameraPrnuEstimateNpArray, prnuNpArray):.4f} (normalized RMS: {rmsDiffNumpy(cameraPrnuEstimateNpArray, prnuNpArray, True):.4f})')
+title = f'Camera PRNU estimate\nRMS with actual one: {rmsDiffNumpy(cameraPrnuEstimateNpArray, prnuNpArray):.4f} (normalized RMS: {rmsDiffNumpy(cameraPrnuEstimateNpArray, prnuNpArray, True):.4f})'
+showImageWithMatplotlib(cameraPrnuEstimateNpArray, title)
 
+_256RangeCameraPrnuEstimateNpArray = cameraPrnuEstimateNpArray - cameraPrnuEstimateNpArray.min()
+_256RangeCameraPrnuEstimateNpArray *= 255 / _256RangeCameraPrnuEstimateNpArray.max()
+
+#showImageWithMatplotlib(_256RangeCameraPrnuEstimateNpArray, title, 'gray')
+plt.imshow(_256RangeCameraPrnuEstimateNpArray, cmap = 'gray', vmin = 0, vmax = 255)
+plt.show()
\ No newline at end of file