@types/pngjs

What is @types/pngjs?

@types/pngjs provides TypeScript type definitions for the pngjs library, which is used for reading and writing PNG files in Node.js.

What are @types/pngjs's main functionalities?

Reading PNG files

This feature allows you to read PNG files and access their properties such as width and height.

const fs = require('fs');
const PNG = require('pngjs').PNG;

fs.createReadStream('in.png')
  .pipe(new PNG())
  .on('parsed', function() {
    console.log('Width:', this.width);
    console.log('Height:', this.height);
  });

Writing PNG files

This feature allows you to create and write PNG files. The example creates a 100x100 red PNG image.

const fs = require('fs');
const PNG = require('pngjs').PNG;

const png = new PNG({ width: 100, height: 100 });

for (let y = 0; y < png.height; y++) {
  for (let x = 0; x < png.width; x++) {
    const idx = (png.width * y + x) << 2;
    png.data[idx] = 255;
    png.data[idx + 1] = 0;
    png.data[idx + 2] = 0;
    png.data[idx + 3] = 255;
  }
}

png.pack().pipe(fs.createWriteStream('out.png'));

Manipulating PNG data

This feature allows you to manipulate the pixel data of a PNG file. The example inverts the colors of the input PNG.

const fs = require('fs');
const PNG = require('pngjs').PNG;

fs.createReadStream('in.png')
  .pipe(new PNG())
  .on('parsed', function() {
    for (let y = 0; y < this.height; y++) {
      for (let x = 0; x < this.width; x++) {
        const idx = (this.width * y + x) << 2;
        this.data[idx] = 255 - this.data[idx];
        this.data[idx + 1] = 255 - this.data[idx + 1];
        this.data[idx + 2] = 255 - this.data[idx + 2];
      }
    }
    this.pack().pipe(fs.createWriteStream('out.png'));
  });

Other packages similar to @types/pngjs

sharp

Sharp is a high-performance image processing library for Node.js. It supports various image formats including PNG, JPEG, and WebP. Compared to pngjs, Sharp offers more advanced image processing capabilities such as resizing, cropping, and format conversion.

jimp

Jimp is an image processing library for Node.js that supports reading and writing various image formats, including PNG. It provides a wide range of image manipulation features such as resizing, cropping, and color adjustments. Jimp is more feature-rich compared to pngjs but may have a steeper learning curve.

pngjs2

Pngjs2 is a fork of pngjs with additional features and improvements. It offers similar functionalities for reading and writing PNG files but with better performance and additional options. It is a good alternative if you need more features or better performance than pngjs.

README

Installation

npm install --save @types/pngjs

Summary

This package contains type definitions for pngjs (https://github.com/lukeapage/pngjs).

Details

Files were exported from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/pngjs.

Additional Details

• Last updated: Sun, 22 Mar 2020 20:51:30 GMT
• Dependencies: @types/node
• Global values: none

Credits

These definitions were written by Jason Cheatham, Florian Keller, and Piotr Błażejewicz.