To display a high-quality 8k PNG wallpaper, you can use the fast-png library to encode and decode the image. Here's an example code snippet using Node.js:

const fastPng = require('fast-png');

// Load the 8k PNG image
const imgBuffer = Buffer.from('your-8k-PNG-wallpaper-image', 'binary');
const img = fastPng.decode(imgBuffer);

// Encode the image to a buffer
const encodedImg = fastPng.encode(img, { quality: 95 });

// Save the encoded image to a file (optional)
fastPng.save(encodedImg, 'path/to/output.png');

// Display the decoded image (using a library like sharp or canvas)

Note that this code assumes you have the fast-png library installed via npm. You can install it by running npm install fast-png in your terminal.

Keep in mind that displaying 8k PNG images may require significant system resources and memory, so be sure to test the image on a suitable device before using it as a wallpaper.