Resolve "Blue band read"

Closes #93 (closed)

python/s2snow/fsc_config.py

@@ -311,11 +311,15 @@ class FscConfig:
 
             blue_band = input.get("blue_band", None)
             if blue_band is not None:
-                self.blue_band = blue_band.get("no_band", 1)
-                self.blue_band_path = blue_band.get("path", None)
-            else:
-                self.blue_band_no_band = 1
-                self.blue_band_path = None
+                blue_band_no_band = blue_band.get("no_band", None)
+                if blue_band_no_band is not None:
+                    self.blue_band_no_band = blue_band_no_band  # surcharge avec la valeur dans le fichier de configuration
+                else:
+                    if self.blue_band_no_band is None:
+                        self.blue_band_no_band = 1  # default value
+                blue_band_path = green_band.get("path", None)
+                if blue_band_path is not None:
+                    self.blue_band_path = blue_band_path  # surcharge avec la valeur dans le fichier de configuration
             
             green_band = input.get("green_band", None)
             if green_band is not None: