iOS: For reasons ranging from risqué to super-spy, you might occasionally want to send a secret image to somebody. While there are plenty of apps you can use to send disappearing images, Cammeleon is a cool little iOS app that lets you hide images within images.

Windows: Here's the problem: The HEIF image format, which Apple now uses in iOS 11 in the form of HEIC files, is a great alternative to JPEG. HEIC images eat up less space and support plenty of extra features, such as depth maps and 16-bit colour. Great. Wonderful.

When you embed any static image onto Twitter, it tries to compress it down as a JPEG to save bandwidth. For photos, that's usually fine; JPEG was designed for photos. But digital art, infographics and screenshots usually look their best in the PNG image format. If you upload those as PNGs, Twitter will still compress them into JPEGs and they might come out crappy. Here's how to fix that.

At a for-profit editorial outlet like Lifehacker, when we need an image for our posts, we can't just do a Google image search and slap up the first result. We have to use properly licensed photos. Sometimes we use our own original photos, sometimes stock images that we pay for, sometimes the millions of Flickr photos licensed for free use through Creative Commons.

Dust thou art, and unto dust shalt thou return, unless thou pay Photobucket $500/year. The 14-year-old photo hosting site recently stopped letting outside sites display its photos for free, a move that instantly broke images on blogs, home pages, and eBay and Amazon listings, and infuriated longtime users. Some users are even having trouble downloading their own images, driving home an expensive lesson: Never trust a third-party site to hold onto your photos forever.

Most of us don't look like Instagram models (we all know those semi-famous people with a constant stream of flawless Instagram poses), but that doesn't mean we can't look as good in our photos as they do. You just have to have a few tricks up your sleeve when your friend whips out their phone and says, "I'm 'gramming this!"

Everyone loves group photos, but getting one where everyone looks natural when they know they're on camera isn't easy. The key is to look as relaxed as possible, even if you're the one taking the shot and encouraging your subjects to pose. Here's what we mean.

Sharpening a photo digitally can be a helpful way to bring out the textures in a soft image, but sharpening too much can create an annoying 'ghost' effect around hard lines. Here's a better way to do it in Photoshop without overemphasising the hard edges.

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.

iOS: Messages can take up a lot of space on your iPhone. It's simple enough to go in and delete old messages (and the photos that came with them) to free up space. However, there's another option: Lower your image quality and size to begin with.

Photography enthusiast site 500px has a new tool that lets you search for photos by sketching them. Have a vague idea of what you want to see or a memorable picture that you haven't been able to find? Just channel your inner Van Gogh.

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.

Have a bunch of still images you'd like to turn into an animated GIF? Blogger Jacob Salmela's shows off how to add that option to the right-click menu with Automator.

Adobe Photoshop is the market leader when it comes to photo retouching, image editing, and creating new images from scratch. However, for most people's needs, it may just be too many features to wade through, too much money to spend, or too complicated to use. Thankfully, there are plenty of powerful alternatives. Here's a look at five of the best.

If you use Facebook, you've probably uploaded a picture at some point. While Facebook is great for sharing, it also uses some pretty ruthless compression that makes your pictures look like crap. Here's how to prevent that from happening.

Chrome: I love a good GIF party as much as anyone, but if I'm on a page with a constantly looping animation, it gets on my nerves pretty quickly. Google just released a Chrome extension that allows you to block animations entirely, or set them to play only once.

iOS: You have a billion options for different photo-editing apps on iOS, but Filters might be one of the simplest to use. It comes packed with over 800 different photo filters, but it still manages to be friendly to use.

Need to get a high-resolution version of an app icon or just want to check out an app's various assets? iDownloadBlog points out that you can easily check out all those images by just dragging and dropping an app to the Preview app.

Composing a picture is about more than just putting your subject inside the frame. This video shows you the basics of photo composition so you can learn to take better photos.