宝塔设置图片跨域
​​​add_header Access-Control-Allow-Origin *;​​​​add_header Access-Control-Allow-Headers X-Requested-With;​​​​add_header Access-Control-Allow-Methods GET,POST,OPTIONS;​

server
{
listen 80;
server_name admin.weixuegu.cn www.weixuegu.cn;
index index.php index.html index.htm default.php default.htm default.html;
root /www/wwwroot/admin.weixuegu.cn/public;

#SSL-START SSL相关配置,请勿删除或修改下一行带注释的404规则
#error_page 404/404.html;
#SSL-END

#ERROR-PAGE-START 错误页配置,可以注释、删除或修改
#error_page 404 /404.html;
#error_page 502 /502.html;
#ERROR-PAGE-END

#PHP-INFO-START PHP引用配置,可以注释或修改
include enable-php-73.conf;
#PHP-INFO-END

#REWRITE-START URL重写规则引用,修改后将导致面板设置的伪静态规则失效
include /www/server/panel/vhost/rewrite/admin.weixuegu.cn.conf;
#REWRITE-END

#禁止访问的文件或目录
location ~ ^/(\.user.ini|\.htaccess|\.git|\.svn|\.project|LICENSE|README.md)
{
return 404;
}

#一键申请SSL证书验证目录相关设置
location ~ \.well-known{
allow all;
}


location ~ .*\.(gif|jpg|jpeg|png|bmp|swf)$
{
expires 30d;
error_log off;
access_log /dev/null;
add_header Access-Control-Allow-Origin *;
add_header Access-Control-Allow-Headers X-Requested-With;
add_header Access-Control-Allow-Methods GET,POST,OPTIONS;

}

location ~ .*\.(js|css)?$
{
#expires 12h;
error_log off;
access_log /dev/null;
}
access_log /www/wwwlogs/admin.weixuegu.cn.log;
error_log /www/wwwlogs/admin.weixuegu.cn.error.log;
}
<canvas width=200 height=200 id="thecanvas"></canvas> 
<script>
var url = "http://admin.weixuegu.cn/uploads/20201020/514939f37dc2381fb602abea4f596a81.jpg";
var canvas = document.createElement("canvas");
var ctx = canvas.getContext('2d');

canvas.width = 100;
canvas.height = 100;
var img = new Image();
//设置图片跨域访问
img.crossOrigin = 'anonymous';
img.src = url;
document.body.appendChild(img);
img.onload = function () {
ctx.drawImage(this,0,0,100,100);
var base64 = canvas.toDataURL('image/jpg', 1);
console.log(base64)
};

</script>