The text has been deformed, like a mosaic

When I draw the barcode, the text becomes a mosaic.

code show as below
``` javascript
var canvas = document.createElement("canvas");
JsBarcode(canvas, md5Key, {
format: "CODE128",
height:100,
fontSize:10,
margin:1,
fontOptions:'italic',
font:'Microsoft YaHei',

displayValue:true,
text:tipName + '：' + tip,
textAlign:'left',
textPosition:'buttom',
});
var base64 = canvas.toDataURL("image/png");
```

I found this library when I googled
[polyfill](https://github.com/jondavidjohn/hidpi-canvas-polyfill)
I hope the author can join this or similar processing mechanism，
When I print out using a thermal printer, the text cannot be read.

Start by reproducing the provided CODE128 canvas example in a browser, including the font and text settings, then compare its output with the linked hidpi-canvas-polyfill. Check whether the generated PNG remains readable when printed on a thermal printer; done means the barcode text is no longer rendered as a mosaic.

Written by the indexing model from the issue text.