Pick green band by default, improve mavic 3M support

opendm/multispectral.py

@@ -181,11 +181,13 @@ def get_primary_band_name(multi_camera, user_band_name):
     if len(multi_camera) < 1:
         raise Exception("Invalid multi_camera list")
     
-    # Pick RGB, or Blue if available, otherwise first band
+    # Pick RGB, or Green, or Blue, in this order, if available, otherwise first band
     if user_band_name == "auto":
-        for band in multi_camera:
-            if band['name'].lower() in ['rgb', 'redgreenblue', 'blue', 'b']:
-                return band['name']
+        for aliases in [['rgb', 'redgreenblue'], ['green', 'g'], ['blue', 'b']]:
+            for band in multi_camera:
+                if band['name'].lower() in aliases:
+                    return band['name']
+                
         return multi_camera[0]['name']
 
     for band in multi_camera:

opendm/photo.py

@@ -925,3 +925,6 @@ class ODM_Photo:
             return self.width * self.height / 1e6
         else:
             return 0.0
+    
+    def is_make_model(self, make, model):
+        return self.camera_make.lower() == make.lower() and self.camera_model.lower() == model.lower()

opendm/types.py

@@ -27,7 +27,7 @@ class ODM_Reconstruction(object):
         self.gcp = None
         self.multi_camera = self.detect_multi_camera()
         self.filter_photos()
-
+        
     def detect_multi_camera(self):
         """
         Looks at the reconstruction photos and determines if this
@@ -90,10 +90,8 @@ class ODM_Reconstruction(object):
             # Sort
             mc.sort(key=lambda x: normalized_band_order.get(x['name'].upper(), '9' + band_indexes[x['name']]))
 
-            c = 1
-            for d in mc:
-                log.ODM_INFO(f"Band {c}: {d['name']}")
-                c += 1
+            for c, d in enumerate(mc):
+                log.ODM_INFO(f"Band {c + 1}: {d['name']}")
 
             return mc
 
@@ -116,6 +114,12 @@ class ODM_Reconstruction(object):
             if 'rgb' in bands or 'redgreenblue' in bands:
                 if 'red' in bands and 'green' in bands and 'blue' in bands:
                     bands_to_remove.append(bands['rgb'] if 'rgb' in bands else bands['redgreenblue'])
+                
+                # Mavic 3M's RGB camera lens are too different than the multispectral ones
+                # so we drop the RGB channel instead
+                elif self.photos[0].is_make_model("DJI", "M3M") and 'red' in bands and 'green' in bands:
+                    bands_to_remove.append(bands['rgb'] if 'rgb' in bands else bands['redgreenblue'])
+                
                 else:
                     for b in ['red', 'green', 'blue']:
                         if b in bands: