Visual detection of cars

[kbennett2000]

Right now the app just checks for motion to record laps. Can the app be extended to recognize a car based on an ArUco Marker?

https://claude.ai/chat/0f1b2052-089e-4834-86ed-25df68f60b65

To implement this:

• Install required packages:

  npm install @techstark/opencv-js

• Print ArUco markers -- https://aruco-gen.netlify.app/
• Attach markers to cars (2-3cm size recommended)
• Import and use the component in your existing app

import React, { useEffect, useRef, useState } from 'react';
import cv from '@techstark/opencv-js';

const ArucoDetector = () => {
  const videoRef = useRef(null);
  const canvasRef = useRef(null);
  const [detectedIds, setDetectedIds] = useState([]);

  useEffect(() => {
    const setupCamera = async () => {
      const stream = await navigator.mediaDevices.getUserMedia({ video: true });
      videoRef.current.srcObject = stream;
    };

    setupCamera();
    return () => {
      if (videoRef.current?.srcObject) {
        videoRef.current.srcObject.getTracks().forEach(track => track.stop());
      }
    };
  }, []);

  const detectMarkers = () => {
    const video = videoRef.current;
    const canvas = canvasRef.current;
    const context = canvas.getContext('2d');

    // Match canvas size to video
    canvas.width = video.videoWidth;
    canvas.height = video.videoHeight;

    // Draw current frame
    context.drawImage(video, 0, 0, canvas.width, canvas.height);

    // Convert to OpenCV format
    const imageData = context.getImageData(0, 0, canvas.width, canvas.height);
    const mat = cv.matFromImageData(imageData);

    // Setup ArUco detector
    const dictionary = new cv.aruco.Dictionary(cv.aruco.DICT_4X4_50);
    const parameters = new cv.aruco.DetectorParameters();

    // Detect markers
    const corners = new cv.Mat();
    const ids = new cv.Mat();
    cv.aruco.detectMarkers(mat, dictionary, corners, ids, parameters);

    if (ids.rows > 0) {
      // Draw detected markers
      cv.aruco.drawDetectedMarkers(mat, corners, ids);

      // Update detected IDs state
      const detectedArray = Array.from(ids.data32S);
      setDetectedIds(detectedArray);
    }

    // Display result
    cv.imshow(canvas, mat);

    // Cleanup
    mat.delete();
    corners.delete();
    ids.delete();
  };

  return (
    <div className="w-full max-w-2xl mx-auto p-4">
      <video 
        ref={videoRef}
        className="w-full h-auto mb-4"
        autoPlay
        playsInline
        onPlay={() => {
          setInterval(detectMarkers, 50); // 20fps detection
        }}
      />
      <canvas 
        ref={canvasRef}
        className="w-full h-auto"
      />
      <div className="mt-4">
        <h3 className="text-lg font-semibold">Detected Cars:</h3>
        <ul>
          {detectedIds.map(id => (
            <li key={id} className="py-1">Car #{id}</li>
          ))}
        </ul>
      </div>
    </div>
  );
};

export default ArucoDetector;

[kbennett2000]

Added ArUco Marker detection to code, it doesn't work so well if something is moving fast. Scrapping this idea for now...

[kbennett2000]

Let's try this with multicolor LEDs!! -- https://claude.ai/chat/96a49907-20ac-420c-b3da-bc18f3570831