JSON 交換/分享group
https://t.me/joinchat/BqjFB1YYrfxfc7qTDRj2jQ
tempImg.src = $(this).attr('src');
var scale = Math.min(512/tempImg.width,512/tempImg.height)
var x = 256 - (tempImg.width/2) * scale
var y = 256 - (tempImg.height/2) * scale
tempContext.drawImage(tempImg, x, y, tempImg.width*scale, tempImg.height*scale);
src
folder入面啲webp檔就可以