When it comes to digital images, colours aren't simply stored as red, green and blue. In fact, they're modified so darker values are stored with more granularity than brighter ones. Unfortunately, if an image editor, such as Photoshop, doesn't take this into consideration when say, blurring, you'll get an incorrect -- and sometimes poor-looking -- result.

Last week, my favourite web-based photo editor, PicMonkey, started charging users. As it turns out, PicMonkey has also been a favourite with a good number of my Lifehacker coworkers. It's easy, lightweight and makes small edits like resizing photos or creating collages (stuff we do here pretty regularly) super simple. I've been using it almost every day, multiple times a day, for years.

Adobe's Creative Suite is one of the best software packs out there for professionals, but the suite is prohibitively expensive for most people - and it's about to get even pricier in Australia. If you can't drop the cash, you can still get a similar experience with free or cheap software. Here's how to build your own Creative Suite.

Windows/Mac/Linux: If you're on the lookout for a digital painting tool and Photoshop is too expensive, Krita is a fast, free and open source art tool that was developed by artists looking for something that met their needs without a ton of bloat or overhead. Plus, it's completely cross-platform.

When it comes to photo-editing software, Adobe leads the pack. So, whether you’re pursuing a career in design or just looking to pick up a new skill, the Adobe Super Bundle is the perfect way to start.

Preview is one of the best parts of macOS. It's an image viewer, lightweight PDF editor and more. Six Colours reminds us that it's also probably the simplest way to quickly batch resize a bunch of images.

Sometimes it takes more than simple colour correction to make a good photo into a great photo. If you have a scenic picture that could use just a little more warmth to make it pop, try adding some extra light in Photoshop with "light bleeding".

The first time you picked up Photoshop, I'm sure you made some criminally bad decisions with filters and effects. We all did. It's the natural result of learning via trial and error. But have you completely excised your novice Photoshop habits? Here are ten you definitely shouldn't be doing.

iOS: Image annotation is one of those surprisingly useful tools on your iPhone, and while there's a built-in option with iOS, you can't do much with it. Annotable offers a ton of features for easy image markup.

It's easy to become reliant on plug-ins for simple editing tasks when in reality, a lot of these effects can be accomplished with a little knowledge of Photoshop's built-in functionality. Take "dynamic contrast" -- turns out you can do this yourself with the help of PS' Unsharp Mask, High Pass filter and blend modes.

Either you're an artist or a programmer. Of course, there are multi-talented folk out there that can do both well, but if you only fall into the latter category and wish you could just "code" pictures to your specifications, then a new, shader-based image editor called Shadron is worth a look.

Last week we saw comparisons between image formats for single-pixel images. But what about the other extreme -- massive, single-colour pictures? Once again, Cloudinary's Jon Sneyers dives into the world of compression to see if JPEG, PNG or GIF comes out on top.

If you're working on an image in Photoshop that's cut into numerous sections, sometimes you find yourself needing to carefully align the different layers just by eye. Set one layer to the "difference" blend mode, though and it's infinitely easier.

The digital equivalent of the question "How long is a piece of string?" could be "How big is a pixel?" The naive answer is "four bytes" -- one for each colour channel (RGB) and alpha -- but depending on the file format, a pixel could be much bigger, ranging from a few to hundreds of bytes.

iOS: Pixelmator is a surprisingly robust image editing tool on iPhone and iPad, and today it's getting a bit easier to use with new selection tools.

Mac: The new Pixelmator update, 3.5 Canyon, brings Quick Selection and Magnetic Selection tools, as well as a Retouch Extension for the Mac's Photos app.

If you need to resize a bunch of images on your Mac, Automator is the way to do it in one fell swoop. 9to5Mac shows off how to quickly make your own Automator service for doing just that.

iOS: Pixelmator is already a pretty great photo editing app on iOS, but the most recent update takes advantage of the new 3D Touch feature on the iPhone 6s in just the way you'd expect it to, with touch-sensitive painting.

Mac: Pixelmator, our favourite image editing software on the Mac, was updated today with a couple of cool features for El Capitan, including split screen support and a Photos extension.