I am new to Raspberry Pi and I want to do real-time object detection using YOLOv8 tentatively (will change if the fps is too low). I realize that by using the code below, it can't detect Pi Cam as the source and run into an error. The Pi Cam works fine with libcamera-hello and managed to capture photo everything. I also enabled the legacy camera feature. The code works fine with USB webcam.


from ultralytics import YOLO

model = YOLO('best.pt')
results = model.predict(source=0, show=True)


Error: ConnectionError: 1/1: 0... Failed to read images from 0

I thought of one solution which is to capture image every time and pass to the model to predict, but it only produces an image every 2.5s. I guess maybe the model reinitialize every time it predicts an image again.


import cv2
from picamera2 import Picamera2
from ultralytics import YOLO
import numpy as np


picam2 = Picamera2()
picam2.configure(picam2.create_preview_configuration(main={"format": 'XRGB8888', "size": (640, 480)}))

model = YOLO('best.pt')

while True:
    im = picam2.capture_array()

    img = cv2.cvtColor(im, cv2.COLOR_BGR2RGB)
    results = model.predict(img)

    for box in results[0].boxes:
        x = int(np.floor(box[0].xywh[0][0].item()))
        y = int(np.floor(box[0].xywh[0][1].item()))
        w = int(np.floor(box[0].xywh[0][2].item()))
        h = int(np.floor(box[0].xywh[0][3].item()))
        cv2.rectangle(im, (x, y), (x + w, y + h), (0, 255, 0))

    cv2.imshow("Camera", im)

So, there are two questions in my mind:

  1. How to set Pi Cam as the default source=0 to have real-time object detection using YOLOv8?
  2. How to prevent reinitialization of the YOLO model for image prediction? (If my guess is correct)

2 Answers 2


I got an idea:

  1. to see if the Pi Cam can be detected by your computer
    in cmd: 'pip install pygame'
    and run the following python code
    import pygame.camera
    camera_id_list = pygame.camera.list_cameras()
    If the result comes out to be 0 which is the id of your computer own cam, you can't use the Pi cam directly.If there are other numbers in the result, you can try by changing to 'source=1' for example.

  2. to get other components provided by raspberrypi
    I don't have an intimate knowledge of this, so I can't offer you some valuable suggestions.

  3. to read the picamera document
    click the link: https://picamera.readthedocs.io/en/release-1.13/recipes2.html
    and you can see something helpful for you in the section 4.2 Capturing to an OpenCV object


Check out the Ultralytics docs on this: https://docs.ultralytics.com/guides/raspberry-pi/#quick-start-with-yolov8

  • While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
    – Milliways
    Dec 3, 2023 at 1:07

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