Add new function that checks whether faces are sufficiently in ROI

tests/test_utils.py

@@ -26,7 +26,7 @@
 
 from vitallens.client import Method
 from vitallens.utils import load_config, probe_video_inputs, parse_video_inputs
-from vitallens.utils import merge_faces, check_faces
+from vitallens.utils import merge_faces, check_faces, check_faces_in_roi
 
 @pytest.mark.parametrize("method", [m for m in Method])
 def test_load_config(method):
@@ -152,4 +152,21 @@ def test_check_faces_n_frames_n_dets_not_matching_2():
 def test_check_faces_invalid_dets():
   with pytest.raises(Exception):
     _ = check_faces([1, 3, 2, 2], inputs_shape=(2, 10, 10, 3))
-
+
+@pytest.mark.parametrize("scenario", [([[0.4, 0.4, 0.6, 0.6], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.5), True), # Fully in ROI
+                                      ([[0.2, 0.4, 0.6, 0.6], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.5), True), # Slightly out to left but ok
+                                      ([[0.0, 0.4, 0.4, 0.6], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.5), False), # Too much out to left
+                                      ([[0.5, 0.4, 0.9, 0.6], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.2, 0.5), True), # Slightly out to right but ok
+                                      ([[0.5, 0.4, 0.9, 0.6], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.6, 0.5), False), # Too much out to right
+                                      ([[0.4, 0.2, 0.6, 0.5], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.5), True), # Slightly out to top but ok
+                                      ([[0.4, 0.1, 0.6, 0.5], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.6), False), # Too much out to top
+                                      ([[0.4, 0.5, 0.6, 0.8], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.5), True), # Slightly out to bottom but ok
+                                      ([[0.4, 0.6, 0.6, 0.9], [0.4, 0.4, 0.6, 0.6]], [0.3, 0.3, 0.7, 0.7], (0.5, 0.5), False), # Too much out to bottom
+                                      ])
+def test_check_faces_in_roi(scenario):
+  faces = np.asarray(scenario[0])
+  roi = np.asarray(scenario[1])
+  percentage_required_inside_roi = scenario[2]
+  expected = scenario[3]
+  actual = check_faces_in_roi(faces=faces, roi=roi, percentage_required_inside_roi=percentage_required_inside_roi)
+  assert expected == actual

vitallens/utils.py

@@ -246,6 +246,31 @@ def check_faces(
     raise ValueError("Face detections are invalid, should be in form [x0, y0, x1, y1]")
   return faces
 
+def check_faces_in_roi(
+    faces: np.ndarray,
+    roi: np.ndarray,
+    percentage_required_inside_roi: tuple = (0.5, 0.5)
+  ) -> bool:
+  """Check whether all faces are sufficiently inside the ROI.
+
+  Args:
+    faces: The faces. Shape (n_faces, 4) in form (x0, y0, x1, y1)
+    roi: The region of interest. Shape (4,) in form (x0, y0, x1, y1)
+    percentage_required_inside_roi: Tuple (w, h) indicating what percentage
+      of width/height of face is required to remain inside the ROI.
+  Returns:
+    out: True if all faces are sufficiently inside the ROI.
+  """
+  faces_w = faces[:,2] - faces[:,0]
+  faces_h = faces[:,3] - faces[:,1]
+  faces_inside_roi = np.logical_and(
+    np.logical_and(faces[:,2] - roi[0] > percentage_required_inside_roi * faces_w,
+                   roi[2] - faces[:,0] > percentage_required_inside_roi * faces_w),
+    np.logical_and(faces[:,3] - roi[1] > percentage_required_inside_roi * faces_h,
+                   roi[3] - faces[:,1] > percentage_required_inside_roi * faces_h))
+  facess_inside_roi = np.all(faces_inside_roi)
+  return facess_inside_roi
+
 def convert_ndarray_to_list(d: Union[dict, list, np.ndarray]):
   """Recursively convert any np.ndarray to list in nested object.