losseless canvas increase size

losseless canvas increase size

JavaScript

fetch('https://picsum.photos/500/500/?random')
.then(res => res.blob())
.then(blob => {
  const orig = new Image()
  orig.src = URL.createObjectURL(blob)
  document.body.append(orig, 'original size ', blob.size)
  createImageBitmap(blob).then(bitmap => {
    var canvas = new OffscreenCanvas(bitmap.width, bitmap.height)
    canvas.getContext('2d').drawImage(bitmap, 0, 0)
    canvas.convertToBlob({
      type: blob.type,
      quality: 1
    }).then(blobFromCnavas => {
      var img = new Image()
      img.src = URL.createObjectURL(blobFromCnavas)
      document.body.append(img, 'canvas size ', blobFromCnavas.size)
    })
  })
})