Day18 TensorFlow.js 即時物件辨識

第 11 屆 iThome 鐵人賽

DAY 19

自我挑戰組

Tensorflow.js初學筆記系列第 19 篇

11th鐵人賽

qu4qu426com123

2019-10-05 23:50:56

2649 瀏覽

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今天一樣是用Google提供的model
一樣不多說，直接先上程式碼

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>coco ssd</title>
    <!-- TensorFlow.js Core -->
    <script src="https://cdn.jsdelivr.net/npm/@tensorflow/tfjs/dist/tf.min.js">
    </script>
    <!-- TensorFlow.js coco ssd-->
    <script src="https://cdn.jsdelivr.net/npm/@tensorflow-models/coco-ssd">
    </script>
    <style>
        video{
            visibility: hidden;
        }
    </style>
</head>

<body>
    <canvas id="detect_result"></canvas>
    <video autoplay playsinline muted id="webcam" ></video>
    <script>
        async function app() {
            const model = await cocoSsd.load();
            const webcamElement = document.getElementById('webcam');
            const canvas = document.getElementById('detect_result');
            const context = canvas.getContext('2d');

            const color = ["green", "yellow", "red"]

            let showResult = async function () {
                const result = await model.detect(webcamElement);
                canvas.width = webcamElement.videoWidth;
                canvas.height = webcamElement.videoHeight;
                context.drawImage(webcamElement, 0, 0);
                context.font = '40px Arial';

                for (let i = 0; i < result.length; i++) {
                    context.beginPath();
                    //three dots mean spread over object get all its properties
                    context.rect(...result[i].bbox);
                    context.lineWidth = 5;
                    context.strokeStyle = color[i % 3];
                    context.fillStyle = color[i % 3];
                    context.stroke();
                    context.fillText(
                        result[i].score.toFixed(3) + ' ' + result[i].class,
                        result[i].bbox[0],
                        result[i].bbox[1] - 5);
                }
                setTimeout(function () {
                    showResult();
                }, 300);
            }
            let setupWebcam = function () {
                return new Promise((resolve, reject) => {
                    const navigatorAny = navigator;
                    navigator.getUserMedia = navigator.getUserMedia ||
                        navigatorAny.webkitGetUserMedia || navigatorAny.mozGetUserMedia ||
                        navigatorAny.msGetUserMedia;
                    if (navigator.getUserMedia) {
                        navigator.getUserMedia({
                                video: true
                            },
                            (stream) => {
                                webcamElement.srcObject = stream;
                                webcamElement.addEventListener('loadeddata', () => resolve(),
                                    false);
                            },
                            (err) => reject(err));
                    } else {
                        reject("getUserMedia failed");
                    }
                });
            }
            setupWebcam().then(
                () => {
                    showResult();
                },
                (err) => {
                    console.log(err);
                }
            )
        }
        app();
    </script>
</body>

</html>

結果