Viewpoint Jon Bentley
Should the High Efficiency Image Format, or HEIF, replace JPEG as the compressed image format of choice for photographers?
High Efficiency Image Format (HEIF) or JPEG for photography? It’s a question that’s been intriguing me since the launch of Apple’s iOS 11 last autumn, when most recent iPhones started recording stills in HEIF by default.
It’s not Apple’s format but an invention of the Moving Picture Experts Group (MPEG), an international body that develops audio and video compression standards. It says it offers higher quality, smaller file sizes and a number of other advantages over the near-universal JPEG format that was created in 1992, at the dawn of digital photography, by another outfit, the Joint Photographic Experts Group. Computing power back then was a fraction of today’s, and compression tools couldn’t be so effective, hence the pressure for an update.
It’s not the first attempt to replace JPEG, but with Google now including it in their Android operating system later this year, HEIF appears to be gaining some ground and might even conceivably appear on dedicated cameras.
First impressions
To find out whether the JPEG’s days are indeed numbered I took a variety of pictures in both JPEG and HEIF formats on two iPhones and examined the results. On first impressions both sets looked equally good. But the HEIF files were half the size of the JPEG ones – good news if you’re short on storage. Moving in to look at the pictures in pixel-peeping detail, the HEIF images actually appeared ever-so-slightly better. On some shots of a Spitfire model, for example, there was a hint more texture and detail. HEIF also supports a wider range of features including burst shoots, non-destructive cropping and rotation,16bit colour depth and physical depth data.
In spite of these advantages I’ve left my iPhone recording JPEGs not HEIFs; you still have the choice in Settings. Why? Well for a start, while you can send someone a JPEG without compatibility concerns even crossing your mind, HEIF is currently incompatible with virtually everything. Lightroom won’t even read it for instance. Apple realises this. So, when you transfer an HEIF image to a PC, send it via iMessage or AirDrop, or do virtually anything else with it, your phone will convert it into a JPEG first; a JPEG that’s often rather larger than if it had been shot in that format originally.
Another factor is licensing. The JPEG people are committed to keeping their format free to use. MPEG’s HEIF on the other hand comes with the irksome encumbrance of licensing costs. Camera and software makers need to pay to use it. This can be particularly awkward for creators and users of free software.
There’s also the prospect of alternative, royalty-free JPEG successors on the horizon. An encoding format for internet video, AV1, being developed by the Alliance for Open Media, will include a new, free-to- use stills file type. And JPEG (the group) is devising an improved version of their venerable format, which promises to match HEIF levels of compression efficiency and offer similar features, including greater colour depth. It’s called JPEG XL and is set to appear in October 2019.
It can’t come soon enough. Please don’t replace JPEG with HEIF, replace it with a format that, as well as squashing your pictures effectively, is also universal and free The world will be a much happier place.