Bugfix/metadata utctime error negative subsec

micasense/metadata.py

@@ -128,11 +128,12 @@ def utc_time(self):
         str_time = self.get_item('EXIF:DateTimeOriginal')
         if str_time:
             utc_time = datetime.strptime(str_time, "%Y:%m:%d %H:%M:%S")
-            subsec = float(f"0.{self.get_item('EXIF:SubSecTime')}")
+            subsec = int(self.get_item('EXIF:SubSecTime'))
             negative = 1.0
             if subsec < 0:
                 negative = -1.0
                 subsec *= -1.0
+            subsec = float(f"0.{int(subsec)}")
             subsec *= negative
             ms = subsec * 1e3
             utc_time += timedelta(milliseconds=ms)

tests/conftest.py

@@ -195,3 +195,7 @@ def meta_bad_exposure(rededge_files_dir: Path):
 @pytest.fixture()
 def meta_altum_dls2(altum_flight_image_name):
     return metadata.Metadata(altum_flight_image_name)
+
+@pytest.fixture()
+def meta_negative_subsec(rededge_files_dir: Path):
+    return metadata.Metadata(str(rededge_files_dir / 'IMG_0008_1.tif'))

tests/test_metadata.py

@@ -67,6 +67,11 @@ def test_utc_time(meta):
     assert utc_time is not None
     assert utc_time.strftime('%Y-%m-%d %H:%M:%S.%f') == '2022-04-06 18:50:25.983430'
 
+def test_utc_time_negative_subsec(meta_negative_subsec):
+    utc_time = meta_negative_subsec.utc_time()
+    assert utc_time is not None
+    assert utc_time.strftime('%Y-%m-%d %H:%M:%S.%f') == '2018-07-25 05:53:52.762886'
+
 
 def test_position(meta):
     assert meta.position() == pytest.approx((47.7036143, -122.1414373, 6.728))