convolve

Canvas convolution filter.


API

$3

Apply convolution filter matrix to the given input, populating result.

Example

``js
var convolve = require('convolve');
var canvas = document.querySelector('canvas');
var ctx = canvas.getContext('2d');

var img = new Image;
img.onload = draw;
img.src = 'maru.jpg';

var sharpen = [
[0, -3, 0],
[-3, 21, -3],
[0, -3, 0]
];

var blur = [
[1, 1, 1],
[1, 1, 1],
[1, 1, 1]
];

var emboss = [
[-18, -9, 0],
[-9, 9, 9],
[0, 9, 18]
];

var edges = [
[0, 9, 0],
[9, -36, 9],
[0, 9, 0]
];

function draw() {
canvas.width = img.width;
canvas.height = img.height;
ctx.drawImage(img, 0, 0);
var data = ctx.getImageData(0, 0, img.width, img.height);
var result = ctx.createImageData(img.width, img.height);
convolve(data, result, img.width, img.height, edges);
ctx.putImageData(result, 0, 0);
}
``

License

MIT