Here's an example code for face mesh detection using Tensorflow.js in Next.js. I'll be using the @tensorflow-models/face-landmarks-detection package which provides the functionality to detect facial landmarks.

First, you need to install the necessary packages. Open your terminal and run the following command:

bash
 
 
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npm install @tensorflow/tfjs @tensorflow-models/face-landmarks-detection next react react-dom

Once you have them installed, you can create a new component in your Next.js application.

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import React, { useEffect, useRef } from 'react';
import * as tf from '@tensorflow/tfjs';
import * as facemesh from '@tensorflow-models/face-landmarks-detection';

const FaceMeshDetection = () => {
  const videoRef = useRef(null);
  const canvasRef = useRef(null);

  useEffect(() => {
    const runFacemesh = async () => {
      const net = await facemesh.load(facemesh.SupportedPackages.mediapipeFacemesh);

      const videoTag = videoRef.current; // Get the video element

      const canvasTag = canvasRef.current; // Get the canvas element
      const ctx = canvasTag.getContext('2d');

      videoTag.width = videoTag.videoWidth;
      videoTag.height = videoTag.videoHeight;

      canvasTag.width = videoTag.videoWidth;
      canvasTag.height = videoTag.videoHeight;

      const predictions = await net.estimateFaces(videoTag);

      ctx.drawImage(videoTag, 0, 0, canvasTag.width, canvasTag.height);

      if (predictions.length > 0) {
        for (let i = 0; i < predictions.length; i++) {
          const keypoints = predictions[i].scaledMesh;

          for (let j = 0; j < keypoints.length; j++) {
            const [x, y] = keypoints[j];
            ctx.beginPath();
            ctx.arc(x, y, 1 /* radius */, 0, 2 * Math.PI, true);
            ctx.fillStyle = 'red';
            ctx.fill();
          }
        }
      }

      requestAnimationFrame(runFacemesh);
    };

    runFacemesh();
  }, []);

  return (
    <div>
      <video ref={videoRef} autoPlay muted playsInline />
      <canvas ref={canvasRef} />
    </div>
  );
};

In the code above, we imported the necessary packages, @tensorflow/tfjs and @tensorflow-models/face-landmarks-detection. We also create a new component FaceMeshDetection.

The useEffect hook is used to load the facemesh model and estimate the facial landmarks using the webcam feed. We then draw detected landmarks on a canvas element.

The requestAnimationFrame(runFacemesh) method is used to recursively call the runFacemesh function which will keep detecting facial landmarks.

Finally, we return a div element containing a video element and a canvas element, both of which are assigned respective ref's via useRef hook.

Remember to add some CSS styles to your component to make it look good.

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video {
  width: 600px;
  height: 400px;
}

canvas {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: -1;
}

Hope this helps!