diff --git a/functions_for_rasterio.py b/functions_for_rasterio.py
index 2c76300b4fe5c35c376816fae6d4863341dccc98..563e42ba6341aeddbdc5f6521b555b1814a3c18d 100644
--- a/functions_for_rasterio.py
+++ b/functions_for_rasterio.py
@@ -1,8 +1,21 @@
-import numpy as np
-from skimage.transform import rescale
-import skimage.color as color
+from scipy import ndimage
 
 
+def rcs_pansharpen(xs, pan):
+    """
+    Implemented by me
+    cf https://www.sfpt.fr/hyperspectral/wp-content/uploads/2018/01/May_panorama_pansharpening.pdf
+    """
+
+    xs_zoom = ndimage.zoom(xs, zoom=4)
+    pan_low_pass = ndimage.gaussian_filter(pan, sigma=1)
+
+    pansharpened = xs_zoom * (pan / pan_low_pass)
+    return pansharpened
+
+
+## NOT USED ANYMORE (can not compare speed with OTB)
+"""
 # functions
 def stretch(bands, lower_percent=2, higher_percent=98):
     out = np.zeros_like(bands)
@@ -96,4 +109,5 @@ def pansharpen(m, pan, method='browley', W=0.1, all_data=False):
     if all_data:
         return rgbn_scaled, image, I
     else:
-        return image
\ No newline at end of file
+        return image
+"""
\ No newline at end of file
diff --git a/with_rasterio.py b/with_rasterio.py
index 01dfbd90044c56cce99517bb886deffbeadce308..c363b62322c1d8abdb1c69518eb0be6a1900f765 100644
--- a/with_rasterio.py
+++ b/with_rasterio.py
@@ -1,5 +1,5 @@
 import rasterio
-from functions_for_rasterio import pansharpen
+from functions_for_rasterio import rcs_pansharpen
 
 xs_path = 'xs.tif'
 pan_path = 'pan.vrt'
@@ -17,5 +17,5 @@ print(xs.shape)
 print(pan.shape)
 
 # Pansharpening
-pxs = pansharpen(xs, pan)
+pxs = rcs_pansharpen(xs, pan)