add test for DetectionsMask import/export

fiftyone/__public__.py

@@ -93,6 +93,7 @@
     Classifications,
     Detection,
     Detections,
+    DetectionsMask,
     Polyline,
     Polylines,
     Keypoint,

fiftyone/core/labels.py

@@ -783,7 +783,7 @@ def _to_image(mask, extension):
         if mask.dtype not in (np.uint8, np.uint16, np.uint32, np.uint64):
             raise ValueError(
                 f"object detection mask dtype is '{mask.dtype}',"
-                f" but only uint dtypes are supported."
+                f" but only numpy uint dtypes are supported."
             )
 
         if mask.ndim != 2:
@@ -793,7 +793,7 @@ def _to_image(mask, extension):
         maxval = mask.max()
         if extension == ".png" and maxval >= 2**16:
             raise ValueError(
-                f"max value of {maxval} exceeds upper limit of of uint16 for PNG file"
+                f"max value of {maxval} exceeds upper limit of np.uint16 for PNG file"
             )
         dtype = DetectionsMask._get_uint_dtype(maxval)
         return mask.astype(dtype)

setup.py

@@ -73,6 +73,7 @@ def get_version():
     "starlette>=0.24.0",
     "strawberry-graphql==0.138.1",
     "tabulate",
+    "tifffile",
     "xmltodict",
     "universal-analytics-python3>=1.0.1,<2",
     # internal packages

tests/unittests/label_tests.py

@@ -6,6 +6,8 @@
 |
 """
 import unittest
+from pathlib import Path
+from tempfile import TemporaryDirectory
 
 from bson import Binary, ObjectId
 import numpy as np
@@ -601,6 +603,39 @@ def test_transform_mask(self):
         rgb_to_rgb = focl._transform_mask(int_to_rgb, targets_map)
         nptest.assert_array_equal(rgb_to_rgb, np.zeros((3, 3, 3), dtype=int))
 
+    @drop_datasets
+    def test_detections_mask_io(self):
+        for dtype in (np.uint8, np.uint16, np.uint32, np.uint64):
+            for extension in ("png", "tif"):
+                for test_max in (False, True):
+                    mask = np.arange(9, dtype=dtype).reshape((3, 3))
+                    png_info = np.iinfo(np.uint16)
+                    info = np.iinfo(dtype)
+                    if test_max:
+                        mask[-1, -1] = info.max
+
+                    export_should_fail = (
+                        test_max
+                        and extension == "png"
+                        and mask.max() > png_info.max
+                    )
+
+                    dm = fo.DetectionsMask(mask=mask)
+
+                    with TemporaryDirectory() as tmp_dir:
+                        outpath = Path(tmp_dir) / f"mask.{extension}"
+                        if export_should_fail:
+                            self.assertRaises(
+                                ValueError,
+                                dm.export_mask,
+                                outpath,
+                                update=True,
+                            )
+                        else:
+                            dm.export_mask(outpath, update=True)
+                            imported_mask = dm.get_mask()
+                            nptest.assert_array_equal(mask, imported_mask)
+
 
 class LabelUtilsTests(unittest.TestCase):
     @drop_datasets