get-rgba-palette

Gets a palette of prominent colors from a flat array of RGBA pixels.

Full example:

var palette = require('get-rgba-palette')
var pixels = require('get-image-pixels')
var load = require('img')
var baboon = require('baboon-image-uri')

load(baboon, function(err, img) {
    //get flat RGBA pixels array
    var px = pixels(img)

    //get 5 prominent colors from our image
    var colors = palette(px, 5)
})

RequireBin demo

Returns RGB colors in the form of:

[ [255, 0, 0], [128, 23, 52], [124, 0, 62], etc.. ]

Usage

palette(pixels[, count, quality, filter])

Gets an array of RGB colors from an image (pixels is a flat RGBA array). Defaults to a count of 5 colors and a quality setting of 10.

quality determines the step between each pixel when computing the quantization; higher number means fuzzier quality. Must be > 0.

filter allows you to threshold the RGBA values given to the quantize function. It passes (pixels, index) -- the flat array and index to the RGBA component. Return true to accept the color, or false to reject.

If not specified, the filter function defaults to:

function filter (pixels, index) {
  // offset 3 --> alpha
  return pixels[index + 3] >= 127
}

palette.bins(pixels[, count, quality, filter])

Instead of returning RGB colors, this returns the "bins" for each computed color. This can give you a very rough overview of the distribution of colours in the image. This is fairly arbitrary as the bin size does not always represent the exact number of pixels for that color in the image.

Returns an array of objects:

{
    color: [255, 0, 0],
    size: 12414,
    amount: 0.65
}

Where amount is a percentage for that bin, normalized from the sum of the sizes in the returned bins.

License

MIT, see LICENSE.md for details.