pixels

Pixels is a minimal image processing library written in JavaScript.

$ npm install pixels
$ npm test

var px = require('pixels');

Currently supports read/write for PNG and JPEG.

Usage

Read image into a Float64Array.

var image = px.read('./test/input.jpg', Float64Array);

Reduce image into grayscale bitmap.

// reduce [r, g, b, a, ...] => [x, ...]
px.reduce(image,
  (r, g, b, a) =>
    0.2126 * r +
    0.7152 * g +
    0.0722 * b
);

Expand back to original size and set alpha to a random value.

// expand [x, ...] => [r, g, b, a, ...]
px.expand(image,
  (x) =>
    [x, x, x, Math.random()]
);

Output to file.

px.write('./test/output.png', image);
px.write('./test/output.jpg', image);

Original	Processed PNG	Processed JPEG

All this in 5 lines of code. You can also access the image data directly through image.data. See test/test.js.

API

read(file, type)

Reads an image file into the specified type (TypedArray).

write(file, image)

Writes an image to file.

reduce(image, f)

Reduces blocks of data in an image. Block size is inferred from the number of arguments in f. See blockman.

expand(image, f)

Expands blocks of data in an image. Block size is inferred from the number of arguments in f. See blockman.

map(image, f)

Iterates and applies a mapping function over blocks of data in an image. See blockman.