diff --git a/topologytool.py b/topologytool.py
index 8192664..6828978 100644
--- a/topologytool.py
+++ b/topologytool.py
@@ -1,12 +1,15 @@
 import os
 import shutil
 import sys
-
+from PIL import Image, ImageOps
 from country_iso2ify import get_resolver
 import pycountry
 from country_bounding_boxes import country_subunits_by_iso_code
 import requests
 import ee
+import numpy as np
+import pandas as pd
+import cairocffi as cairo
 
 class Topology:
     def __init__(self,
@@ -20,7 +23,8 @@ class Topology:
                  linemap_cols=30,
                  linemap_width=1.0,
                  linemap_roundcap=True,
-                 linemap_transparent=False
+                 linemap_transparent=False,
+                 storage_directory=None,
                  ):
         self.country = country
         self.refetch_elevation_data = refetch_elevation_data
@@ -35,6 +39,7 @@ class Topology:
         self.subregion_mode = subregion_mode
         self.target_region_name = None
         self.elevation_filename = None
+        self.storage_directory = storage_directory
 
         if self.country is None and self.iso_country is None:
             self.country = "Switzerland"
@@ -106,6 +111,32 @@ class Topology:
             shutil.copyfileobj(response.raw, out_file)
         del response
 
+    def convert_png_to_data(self):
+        elevation_data = Image.open(self.elevation_filename).convert('L')
+        frame_image = Image.new(mode='L', size=(1224,1224), color=0)
+        frame_image.paste(elevation_data,
+                          ((1224 - elevation_data.size[0]) // 2,
+                   (1224 - elevation_data.size[1]) // 2))
+        elevation_data = frame_image
+
+        width, height = elevation_data.size
+        grid_w, grid_h = self.linemap_rows, self.linemap_cols
+
+        # Calculate cell dimensions
+        cell_w = width // grid_w
+        cell_h = height // grid_h
+
+        # Calculate mean values for each cell
+        # future improve -- only average non-zero values to get coastlines and edges right
+        values = np.zeros((grid_h, grid_w))
+        for r in range(grid_h):
+            for c in range(grid_w):
+                # Define box (left, upper, right, lower)
+                box = (c * cell_w, r * cell_h, (c + 1) * cell_w, (r + 1) * cell_h)
+                cell = elevation_data.crop(box)
+                values[r, c] = np.mean(np.array(cell))
+        return values
+
     def create_svg_file(self, rotation=0,file_index=None):
         # if no refetch, check if file exists
         if os.path.exists(self.elevation_filename):
@@ -119,7 +150,7 @@ class Topology:
 
 
 def main():
-    topology = Topology(country="France",
+    topology = Topology(country="Switzerland",
                         subregion_mode=False)
     topology.list_subunits()
     print(topology.get_boundingbox())