顔認識するやつ

facedetect.html

<canvas id="canvas" width="640" height="480"></canvas>
<script>
  const img = new Image;
  img.src = "lena.png";
  let ctx;
  let arr;
  img.onload = () => {
    ctx = canvas.getContext("2d");
    ctx.drawImage(img, 0, 0);
    arr = ctx.getImageData(0, 0, 640, 480).data;
  };
  const fugafuga = new Uint8Array(640 * 480); 
</script>
<script src="opencv.js"></script>
<script>
  cv.onRuntimeInitialized = async () => {
    const fileName = "haarcascade_frontalface_default.xml";
    const frontalface = new Uint8Array(await fetch(fileName).then(res => res.arrayBuffer()));
    cv.FS_createDataFile("/", fileName, frontalface, true, true);
    const classifier = new cv.CascadeClassifier();
    classifier.load(fileName);
    const frame = cv.imread("canvas");
    const grayFrame = new cv.Mat();
    cv.cvtColor(frame, grayFrame, cv.COLOR_RGBA2GRAY);
    cv.equalizeHist(grayFrame, grayFrame);
    const faces = new cv.RectVector();
    classifier.detectMultiScale(grayFrame, faces, 1.1, 3);
    const box = faces.get(0);
    ctx.rect(box.x, box.y, box.width, box.height);
    ctx.stroke();
  };
</script>