Merge pull request #39 from scholi/Bruker_non_square

fix aspect ratio issue

pySPM/Bruker.py

@@ -170,14 +170,20 @@ def get_channel(self, channel="Height Sensor", backward=False, corr=None, debug=
  if debug:
  print("xres/yres", xres, yres)
  scan_size = self.layers[i][b'Scan Size'][0].split()
- aspect_ratio = [int(x) for x in self.layers[i][b'Aspect Ratio'][0].split(b":")]
+ aspect_ratio = [float(x) for x in self.layers[i][b'Aspect Ratio'][0].split(b":")]
+ if len(aspect_ratio)==2:
+ aspect_ratio = aspect_ratio[1]/aspect_ratio[0]
+ elif len(aspect_ratio)==1:
+ aspect_ratio = aspect_ratio[0]
+ has_non_square_aspect_ratio = aspect_ratio<1
  if debug:
  print("aspect ratio", aspect_ratio)
+ print("scan size", scan_size)
  if scan_size[2][0] == 126:
  scan_size[2] = b'u' + scan_size[2][1:]
  size = {
- 'x': float(scan_size[0]) / aspect_ratio[1],
- 'y': float(scan_size[1]) / aspect_ratio[0],
+ 'x': float(scan_size[0]),
+ 'y': [float(scan_size[1]),float(scan_size[1])*yres/xres][has_non_square_aspect_ratio],
  'unit': scan_size[2].decode(encoding)}
  image = pySPM.SPM_image(
  channel=[channel, 'Topography'][channel == 'Height Sensor'],