Live color tracking — computer vision in the browser

Track a coloured object in real time: convert each webcam frame to HSV, threshold a colour range with cv2.inRange, and box the biggest blob — the basis of colour-based object tracking in computer vision. Runs client-side (nothing uploaded). Press Run, allow the camera, and tweak the colour bounds for your object.

Example code (Python / OpenCV)

"""
Live color tracking

Track a coloured object in real time: convert each webcam frame to HSV, threshold a colour range with cv2.inRange, and box the biggest blob — the basis of colour-based object tracking in computer vision. Runs client-side (nothing uploaded). Press Run, allow the camera, and tweak the colour bounds for your object.
"""

import cv2
import numpy as np

# The camera starts automatically on Run — allow access when prompted.
cap = cv2.VideoCapture(0)

while True:
    ret, frame = cap.read()
    if not ret:
        print("No camera frame — allow camera access when prompted.")
        break

    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
    # Track a colour — default: blues. Tweak the bounds for your object.
    mask = cv2.inRange(hsv, (95, 90, 60), (130, 255, 255))
    cnts, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    if cnts:
        c = max(cnts, key=cv2.contourArea)
        if cv2.contourArea(c) > 500:
            x, y, w, h = cv2.boundingRect(c)
            cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 2)

    cv2.imshow("tracking", frame)
    cv2.imshow("mask", mask)

    if cv2.waitKey(1) == 27:  # Esc / Stop
        break

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