HandLandmarker's min_hand_detection_confidence is not consistent #5293
Description
Have I written custom code (as opposed to using a stock example script provided in MediaPipe)
Yes
OS Platform and Distribution
Mac M2
Mobile device if the issue happens on mobile device
No response
Browser and version if the issue happens on browser
No response
Programming Language and version
python
MediaPipe version
0.10.9 (latest version working on Mac - #5168)
Bazel version
No response
Solution
HandLandmarker
Android Studio, NDK, SDK versions (if issue is related to building in Android environment)
No response
Xcode & Tulsi version (if issue is related to building for iOS)
No response
Describe the actual behavior
If a hand is detected at min_hand_detection_confidence=0.71, one would expects that it also finds a hand at all lower thresholds.
Describe the expected behaviour
It is possible to get no detections at a lower confidence threshold even though a larger threshold finds a hand. I also observed the same for FaceLandmarker but I don't have a minimal reproducible example for that at the moment.
Standalone code/steps you may have used to try to get what you need
import mediapipe as mp
from mediapipe.tasks.python import BaseOptions
from mediapipe.tasks.python.vision import (
HandLandmarker,
HandLandmarkerOptions,
)
base_options = BaseOptions(model_asset_path="hand_landmarker.task")
for threshold in range(100):
options = HandLandmarkerOptions(
base_options=base_options,
num_hands=2,
min_hand_detection_confidence=threshold / 100,
)
with HandLandmarker.create_from_options(options) as model:
image = mp.Image.create_from_file("test.png")
if model.detect(image).hand_landmarks:
print(f"Found a hand at {threshold/100}")
# finds a hand for [0.01, 0.36] and for [0.51, 0.71]
# since it detects a hand for min_hand_detection_confidence=0.71,
# it should also detect a hand at all thresholds lower than 0.71!Other info / Complete Logs
test.png:
