SOURCE

new Vue({

    el: "#app",
    data() {
        return {
            dialogVisible: false
        };
    },
    methods: {
        imgBlob(imgUrl) {
            let c= document.createElement('canvas');
    this.imageUrl = imgUrl;
    let img = new Image();
    img.src = imgUrl;
    img.onload = function () {
        c.width = img.width;
        c.height = img.height;
        let ctx = c.getContext('2d');
        ctx.drawImage(img, 0, 0);
        document.getElementById("app").appendChild(c);
        // c.toBlob((blob) => {
        //     let formData = new FormData();
        //     formData.append('file', blob, 'test.jpg');
        // }, 'image/jpeg');
    };
        return c
}
    }
}
)

<div id="app">
<div>
     <canvas id="myCanvas" ></canvas>
   <el-button @click="imgBlob('https://dss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/logo_white-c4d7df0a00.png')">test</el-button>
</div>
</div>

#app{
    background: white;
}