png-dpi-reader-writer
v0.2.4
Published
Reader/Writer for png chunk pHYs on browsers
Downloads
3,222
Readme
png-dpi-reader-writer
Reader/Writer for png image's pHYs chunk on browsers.
Installation
$ npm install png-dpi-reader-writer
Usage
Reader
Detect width, height and DPI for PNG image.
const res = await fetch(srcUrl, {mode: 'cors'})
const arrayBuffer = await res.arrayBuffer()
const {width, height, dpi} = parsePngFormat(arrayBuffer)
Writer
Write DPI for PNG image. See also demo/src/index.js.
const newByteArray = writePngDpi(arrayBuffer, window.devicePixelRatio * 72)
const img = document.querySelector('img')
img.src = convertToDataURI(newByteArray)
Demo
$ npm run start
- http://localhost:9006/demo/index.html
- https://daiiz.github.io/png-dpi-reader-writer/demo/index.html
Related projects
- https://github.com/daiiz/dpi-aware-image