<input type="file" capture="camera" accept="image/*"/>

<input type="file" accept="img/*">

// 访问用户媒体设备
getUserMedia(constrains, success, error) {
    if (navigator.mediaDevices.getUserMedia) {
        //最新标准API
        navigator.mediaDevices.getUserMedia(constrains).then(success).catch(error);
    } else if (navigator.webkitGetUserMedia) {
        //webkit内核浏览器
        navigator.webkitGetUserMedia(constrains).then(success).catch(error);
    } else if (navigator.mozGetUserMedia) {
        //Firefox浏览器
        navagator.mozGetUserMedia(constrains).then(success).catch(error);
    } else if (navigator.getUserMedia) {
        //旧版API
        navigator.getUserMedia(constrains).then(success).catch(error);
    } else {
        this.scanTip = "你的浏览器不支持访问用户媒体设备"
    }
}

success(stream) {
    this.streamIns = stream
    // 设置播放地址，webkit内核浏览器
    this.URL = window.URL || window.webkitURL
    if ("srcObject" in this.$refs.refVideo) {
        this.$refs.refVideo.srcObject = stream
    } else {
        this.$refs.refVideo.src = this.URL.createObjectURL(stream)
    }
    this.$refs.refVideo.onloadedmetadata = e => {
        // 播放视频
        this.$refs.refVideo.play()
        this.initTracker()
    }
},
error(e) {
    this.scanTip = "访问用户媒体失败" + e.name + "," + e.message
}

// 人脸捕捉
initTracker() {
    this.context = this.$refs.refCanvas.getContext("2d")    // 画布
    this.tracker = new tracking.ObjectTracker(['face'])     // tracker实例
    this.tracker.setStepSize(1.7)                           // 设置步长
    this.tracker.on('track', this.handleTracked)            // 绑定监听方法
    try {
        tracking.track('#video', this.tracker)      // 开始追踪
    } catch (e) {
        this.scanTip = "访问用户媒体失败，请重试"
    }
}

// 追踪事件
handleTracked(e) {
    if (e.data.length === 0) {
        this.scanTip = '未检测到人脸'
    } else {
        if (!this.tipFlag) {
            this.scanTip = '检测成功，正在拍照，请保持不动2秒'
        }
        // 1秒后拍照，仅拍一次
        if (!this.flag) {
            this.scanTip = '拍照中...'
            this.flag = true
            this.removePhotoID = setTimeout(() => {
                this.tackPhoto()
                this.tipFlag = true
            }, 2000)
        }
        e.data.forEach(this.plot)
    }
}

<div class="rect" v-for="item in profile"
             :style="{ width: item.width + 'px', height: item.height + 'px', left: item.left + 'px', top: item.top + 'px'}"></div>
// 绘制跟踪框
plot({x, y, width: w, height: h}) {
    // 创建框对象
    this.profile.push({ width: w, height: h, left: x, top: y })
}

// 拍照
tackPhoto() {
    this.context.drawImage(this.$refs.refVideo, 0, 0, this.screenSize.width, this.screenSize.height)
    // 保存为base64格式
    this.imgUrl = this.saveAsPNG(this.$refs.refCanvas)
    // this.compare(imgUrl)
    this.close()
},
// Base64转文件
getBlobBydataURI(dataURI, type) {
    var binary = window.atob(dataURI.split(',')[1]);
    var array = [];
    for(var i = 0; i < binary.length; i++) {
        array.push(binary.charCodeAt(i));
    }
    return new Blob([new Uint8Array(array)], {
        type: type
    });
},
// 保存为png,base64格式图片
saveAsPNG(c) {
    return c.toDataURL('image/png', 0.3)
}