Migrate to Supervision Without an OpenCV Dependency

Supervision no longer installs OpenCV or offers an OpenCV extra. A standard installation includes the NumPy, Pillow, SciPy, and PyAV fallback needed by Supervision's image, drawing, and file-video APIs. When a compatible cv2 is already installed, Supervision selects it once when the process imports the package.

Keep the default fallback

Install Supervision normally when your application does not otherwise require OpenCV:

bash

pip install supervision

The fallback keeps Supervision's documented APIs operational. Some text and anti-aliased drawing pixels can differ from OpenCV, so use the same backend while validating image-level baselines.

Prefer OpenCV behavior

Install exactly one OpenCV wheel family when your application relies on OpenCV outside Supervision or needs its native behavior:

bash

# Servers and containers without OpenCV GUI modules
pip install opencv-python-headless supervision

# Desktop applications that need OpenCV GUI modules
pip install opencv-python supervision

Do not install both opencv-python and opencv-python-headless. If another dependency, such as a model runtime, already provides a compatible cv2, keep that installation instead of adding a second wheel family.

Verify the selected backend

Backend selection happens at import time and lasts for the process lifetime. Run this command in a fresh Python process after changing dependencies:

bash

python -c "from supervision import _cv2; print(_cv2.BACKEND_NAME)"

It prints fallback without OpenCV and the OpenCV backend name when cv2 is available. _cv2 is private; use this command only as an installation diagnostic, not as application API.

Capture webcams yourself

Supervision's video helpers support file paths through either backend. Live camera capture remains application-owned, so install your chosen OpenCV wheel if you use cv2.VideoCapture(0):

python

import cv2
import supervision as sv

capture = cv2.VideoCapture(0)
annotator = sv.BoxAnnotator()

Roll back an upgrade

If a downstream image baseline requires the pre-migration package behavior, pin Supervision below the first release that removes the OpenCV dependency, then plan a backend-specific migration separately:

bash

pip install "supervision<0.30.0"