fast-png

PNG image decoder and encoder written entirely in JavaScript.

Installation

$ npm install --save fast-png

Usage

decode(png[, options])

Arguments

• png - A TypedArray or Buffer that contains the PNG data.
• options - An object of options

Options

• checkCrc - If set to true, the CRC will be checked for each chunk and an error will be thrown in case it's wrong (default: false).

encode(image)

Arguments

• png - An object representing the image. You can pass an ImageData from the Canvas API or an object with the following properties:
  • width - The width of the image
  • height - The height of the image
  • data - An array or TypedArray with the image data
  • depth - A number indicating the color depth (only 8 and 16 are supported now). Default: 8.
  • channels - Number of channels, including alpha (1, 2, 3 and 4 are supported). Default: 4.
  • text - An object with key-value pairs representing tEXt chunks. The keys must have less than 80 characters. The keys and values must have only characters in the latin1 charset (maximum code point of 255). Default: undefined.

hasPngSignature(array)

Returns whether the array starts with the PNG signature (magic bytes).

PNG standard

Spec can be found at: https://www.w3.org/TR/PNG/

License

MIT