Grayscale property passthrough (#99)

* Initial implementation

* Fix basic python and edge cases

* Fix auto-detection

sleap_io/io/video.py

@@ -160,7 +160,13 @@ def num_frames(self) -> int:
  @property
  def img_shape(self) -> Tuple[int, int, int]:
  """Shape of a single frame in the video."""
- height, width, channels = self.get_frame(0).shape
+ height, width, channels = self.read_test_frame().shape
+ if self.grayscale is None:
+ self.detect_grayscale()
+ if self.grayscale is False:
+ channels = 3
+ elif self.grayscale is True:
+ channels = 1
  return int(height), int(width), int(channels)
 
  @property
@@ -578,7 +584,7 @@ def read_test_frame(self) -> np.ndarray:
  frame_idx = list(self.frame_map.keys())[0]
  else:
  frame_idx = 0
- return self.read_frame(frame_idx)
+ return self._read_frame(frame_idx)
 
  @property
  def has_embedded_images(self) -> bool:
@@ -699,7 +705,7 @@ class ImageVideo(VideoBackend):
  This backend supports reading videos stored as a list of images.
 
  Attributes:
- filename: Path to video files.
+ filename: Path to image files.
  grayscale: Whether to force grayscale. If None, autodetect on first frame load.
  """
 

sleap_io/model/video.py

@@ -131,9 +131,16 @@ def grayscale(self) -> bool | None:
  if shape is not None:
  return shape[-1] == 1
  else:
- if "grayscale" in self.backend_metadata:
- return self.backend_metadata["grayscale"]
- return None
+ return self.backend_metadata.get("grayscale", None)
+
+ @grayscale.setter
+ def grayscale(self, value: bool):
+ """Set the grayscale value and adjust the backend."""
+ if self.backend is not None:
+ self.backend.grayscale = value
+ self.backend._cached_shape = None
+
+ self.backend_metadata["grayscale"] = value
 
  def __len__(self) -> int:
  """Return the length of the video as the number of frames."""

tests/model/test_video.py

@@ -122,3 +122,23 @@ def test_video_replace_filename(
  video.replace_filename(centered_pair_frame_paths)
  assert type(video.backend) == ImageVideo
  assert video.exists(check_all=True) is True
+
+
+def test_grayscale(centered_pair_low_quality_path):
+ video = Video.from_filename(centered_pair_low_quality_path)
+ assert video.grayscale == True
+ assert video.shape[-1] == 1
+
+ video.grayscale = False
+ assert video.shape[-1] == 3
+
+ video.close()
+ video.open()
+ assert video.grayscale == False
+ assert video.shape[-1] == 3
+
+ video.grayscale = True
+ video.close()
+ video.open()
+ assert video.grayscale == True
+ assert video.shape[-1] == 1