Picto Box

TypeScript library for interacting with several different image types, including those exclusive to the Wii U and 3DS

Why?

While there are several libraries already available for NodeJS for various image types, most of these have at least one of the following issues:

• Outdated/unmaintained
• Does not completely/accurately follow image specification
• Inconsistent API with other libraries
• API is cumbersome to work with in our systems
• Library is poorly documented or structured, leading to development and/or performance issues
• A library does not exist for the image type

Because of this, we have decided to create our own library with the following goals:

• Consistent API, making image conversions simple and nice to do
• Support a wide range of image types, including those specific to Nintendo consoles
• Follow image specifications as completely and accurately as possible
  • Some images are Nintendo variants of standard formats. In these cases the image specification may not be entirely followed (though compatibility with non-Nintendo images is always a goal)
• Well structured classes with clear field/method names. These names should come from, or be derived by, the images specification
• Good documentation. Including self-documented code, TSDoc comments, regular comments, and linking to reference material to assist with bug fixes/specification inaccuracies

Installation

npm i @pretendonetwork/pictobox

Supported files

• [x] BMP
• [x] TGA
• [x] PNG
• [ ] ETC1A4. Nintendo variant of ETC1 with added alpha data. (Can decode but not encode)
• [ ] Indexed images
• [x] RGB565A4. Nintendo variant of RGB565 with added alpha data

Example

// Convert an RGB565 (with alpha) image to a PNG

import fs from 'node:fs';
import RGB565A4 from '@pretendonetwork/pictobox/rgb565a4';
import PNG from '@pretendonetwork/pictobox/png';

const rgb565Data = fs.readFileSync('./badge.rgb565');
const rgb565Alpha = fs.readFileSync('./badge.a4');

const rgb565 = new RGB565A4();

rgb565.width = 64;
rgb565.height = 64;
rgb565.parseFromBuffer(rgb565Data, rgb565Alpha);

const png = new PNG();

png.width = rgb565.width;
png.height = rgb565.height;
png.pixels = rgb565.pixels;
png.bitDepth = PNG.BitDepths.Bits8;
png.colorType = PNG.ColorTypes.RGBA;
png.interlaceMethod = PNG.InterlaceMethods.None;

const pngEncoded = png.encode();

fs.writeFileSync('./badge.png', pngEncoded);