README.md

pixmap.

THIS PACKAGE IS NOT PUBLISHED YET. ADDING TO VERSION CONTROL BEFORE MY DRIVE BREAKS.

PixMap is a pixel manipulation library, for node & browsers. It supports blending, resizing, blurring, cropping, masking, and, of course, direct pixel manipulation.

PixMap works by delegating decoding and encoding of image formats to third parties like sharp or pngjs.

Installation

yarn add pixmap

or

npm install pixmap --save

API

const PixMap = require('pixmap')

Creating new PixMaps

let pix = new PixMap(100, 100) // 100x100 transparent pixmap

Properties

pix.width // width of the pix
pix.height // height of the pix
pix.data // pixel data, Uint8ClampedArray

I/O

By default, in node, require('pixmap') will give you PixMap with sharp codecs (png, svg, jpeg, tiff, etc). Supported sharp codecs are automatically calculated at runtime using sharp.format.

const PixMap = require('pixmap')

// get pngBuffer somehow
PixMap.loadBuffer(pngBuffer).then((pix) => {
  //...
})

PixMap.loadFile('path/to/file').then((pix) => {
  //...
})

PixMap.toFile('image/png').then(() => {
  console.log('saved.')
})

PixMap.toBuffer('image/png').then((pngBuffer) => {
  // do stuff with pngBuffer
})

Input

Reading from files

PixMap.loadFile('./path/to/image.png').then((pix) => {
  //...
})

Reading from buffers

fs.readFile('./path/to/image.png', (buffer) => {
  PixMap.loadBuffer(buffer).then((pix) => {
    //...
  })
})

When reading from file or buffer, the file-type of the file or buffer is used to get the proper codec and return a new PixMap.

If you want to feed PixMap with a raw buffer of decoded pixels, you can use

let pix = PixMap.fromView(width, height, arrayView)

for example:

let imageData = canvas.getContext('2d').getImageData()
let pix = PixMap.fromView(imageData.width, imageData.height, imageData.data)

PixMap will always favor referencing the original ArrayBuffer rather than copying it, whenever possible (e.g. same number of channels.), so for instance, in the example above, modifying the PixMap pixels will also modify the imageData pixels.

Output

Saving to a file. Refer to the library documentation for their options.

pix.toFile('image/png', './path/to/image.png', {/* options */}).then(() => {
  console.log('done')
})

Saving to a coded buffer. Refer to the library documentation for their options.

pix.toBuffer('image/png', {/* options */}).then((buffer) => {
  fs.writeFile('./path/to/image.png', buffer, () => {
    //..
  })
})

For consistency, loadBuffer / toBuffer always return promises, even if the implemented codec behaves in a syncronous manner.

Convenience constants provided for mime-types

PixMap.MIME.png  === 'image/png'
PixMap.MIME.jpeg === 'image/jpeg'
PixMap.MIME.gif  === 'image/gif'
PixMap.MIME.tiff === 'image/tiff'
PixMap.MIME.svg  === 'image/svg'
PixMap.MIME.webp === 'image/webp'

Iterating over PixMaps

todoc

Compositing

todoc

Cropping

todoc

Masking

todoc

Filtering

todoc

Resizing

todoc

#License

MIT.

Inspired by Jimp / imagejs.