Canvas Filters

By  on  

Adding filters to images can make them more eye-catching and shareable -- just ask Instagram, Snapchat, Prism, and every other app out there.  A few years back we got the awesome CSS filters feature, allowing us to use a fixed set of filter methods to make our photos beautiful.  Of course CSS filters work on standard HTML elements, not just images, but images provide a better illustration of filter effects.

I was happy to see that browsers have recently implemented those same filters for <canvas> element contents.  Let's start with a snippet from my JavaScript Canvas Image Conversion post, converting an image to canvas:

// Converts image to canvas; returns new canvas element
function convertImageToCanvas(image) {
	var canvas = document.createElement("canvas");
	canvas.width = image.width;
	canvas.height = image.height;
	canvas.getContext("2d").drawImage(image, 0, 0);

	return canvas;
}

var canvas = convertImageToCanvas(document.querySelector('img'));

With a <canvas> element ready, we can then implement CSS filters whenever we'd like:

canvas.getContext('2d').filter = 'blur(5px) opacity(0.6)';

You can see a full list of filters on MDN.  I'm pleased that an API that started with CSS has been mirrored within canvas!

Recent Features

Incredible Demos

  • By
    MooTools: Set Style Per Media

    I'd bet one of the most used MooTools methods is the setStyle() method, which allows you to set CSS style declarations for an element. One of the limitations of MooTools' setStyle() method is that it sets the specific style for all medias.

  • By
    WebSocket and Socket.IO

    My favorite web technology is quickly becoming the WebSocket API. WebSocket provides a welcomed alternative to the AJAX technologies we've been making use of over the past few years. This new API provides a method to push messages from client to server efficiently...

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!