Add gps-z-offset

opendm/config.py

@@ -41,6 +41,7 @@
     'geo': 'dataset',
     'gltf': 'mvs_texturing',
     'gps_accuracy': 'dataset',
+    'gps_z_offset': 'dataset',
     'help': None,
     'ignore_gsd': 'opensfm',
     'matcher_neighbors': 'opensfm',
@@ -845,7 +846,17 @@ def config(argv=None, parser=None):
                         'with high precision GPS information (RTK), this value will be automatically '
                         'set accordingly. You can use this option to manually set it in case the reconstruction '
                         'fails. Lowering this option can sometimes help control bowling-effects over large areas. Default: %(default)s')
-
+
+    parser.add_argument('--gps-z-offset',
+                        type=float,
+                        action=StoreValue,
+                        metavar='<float>',
+                        default=0,
+                        help='Set a GPS offset in meters for the vertical axis (Z) '
+                        'by adding it to the altitude value of the GPS EXIF data. This does not change the value of any GCPs. '
+                        'This can be useful for example when adjusting from ellipsoidal to orthometric height. '
+                        'Default: %(default)s')
+
     parser.add_argument('--optimize-disk-space',
                 action=StoreTrue,
                 nargs=0,

opendm/photo.py

@@ -785,6 +785,12 @@ def get_gps_dop(self):
 
     def override_gps_dop(self, dop):
         self.gps_xy_stddev = self.gps_z_stddev = dop
+
+    def adjust_z_offset(self, z_offset):
+        if self.altitude is not None:
+            self.altitude += z_offset
+        else:
+            self.altitude = z_offset
 
     def override_camera_projection(self, camera_projection):
         if camera_projection in projections:

stages/dataset.py

@@ -338,3 +338,10 @@ def parallel_bg_filter(item):
         if args.rolling_shutter and not reconstruction.is_georeferenced():
             log.ODM_WARNING("Reconstruction is not georeferenced, disabling rolling shutter correction")
             args.rolling_shutter = False
+
+        # GPS Z offset
+        if 'gps_z_offset_is_set' in args:
+            log.ODM_INFO("Adjusting GPS Z offset by %s for all images" % args.gps_z_offset)
+
+            for p in photos:
+                p.adjust_z_offset(args.gps_z_offset)