At this year’s WWDC, Apple introduced a new format for still images and video. The container is called High Efficiency Image Format (HEIF), and it uses a codec called High Efficiency Video Coding (HEVC). HEIF files can store still images, video, or both at once. Apple doesn’t have proper documentation on its site, as far as I can see, but a slideshow on HEIF and one on HEVC provide a lot of information. Kelly Thompson provides a technical overview.
Tag Archives: images
Every month. W3Techs records the percentage of websites using popular image file formats. For a long time, PNG was slowly creeping up on JPEG. In the latest numbers, PNG has pulled ahead, being used on 74.1% of websites, against JPEG’s 73.8%. GIF stands at a distant third with 36%, followed by SVG at 3.8%.
Keep in mind, this isn’t the same as saying more PNG images are on the Web than JPEG images. If pages which hold JPEGs contain more of them, there may be more JPEG images even if they aren’t on more sites. Since galleries of JPEG photographs are common, this is a plausible situation.
You can see the trend by looking at the RSS feed. Unfortunately, all links point to the same URL, but if you can view the RSS preview, you can get the old numbers on a monthly basis. The web page is updated daily, which is why the numbers quoted above don’t match the June numbers in the RSS feed.
Reporting carries responsibility. When you tell the public about a risk, you need to tell them what the risk is, not just scare them. An article from Check Point Software Technologies, titled “ImageGate,” shows how bad even tech sites can get at clickbait reporting. According to Wikipedia, Check Point is a business with thousands of employees, not a hole-in-the-wall IT company that hires ghostwriters to write filler.
The article claims:
the attackers have built a new capability to embed malicious code into an image file and successfully upload it to the social media website. The attackers exploit a misconfiguration on the social media infrastructure to deliberately force their victims to download the image file. This results in infection of the users’ device as soon as the end-user clicks on the downloaded file.
This blog doesn’t generally deal with cronyist bullying operations like the International Olympic Committee (IOC). But when the IOC get silly about the file formats it tells people they can’t use, that’s a subject worth mentioning here.
The IOC has decreed that “the use of Olympic Material transformed into graphic animated formats such as animated GIFs (i.e. GIFV), GFY, WebM, or short video formats such as Vines and others, is expressly prohibited.”
Technologies develop to a point where they’re good enough for widespread use. Once a lot of people have adopted them, it’s hard to move on from there to a still better one, since people have invested so much in a technology that works for them. We see this with cell phone communication, which is pretty good but would undoubtedly be much better if it could be invented all over today. We see it with the DVD format, which Blu-Ray hasn’t managed to push aside in spite of huge marketing efforts. And we see it in file formats.
Most of today’s highly popular formats have been around since the nineties. For images, we still have TIFF, JPEG, PNG, and even the primitive GIF format, which goes back to the eighties. In audio, MP3 still dominates, even though there are now much better alternatives.
This is a good thing in many ways. If new, improved formats displaced old ones every five years, we’d be constantly investing in new software, and anyone who didn’t upgrade would be unable to read a lot of new files. Digital preservation would be a big headache, as archivists would need to migrate files repeatedly to avoid obsolescence.
It does mean, though, that we’re working with formats that have deficiencies which often have grown in importance. JPEG compression isn’t nearly as good as what modern techniques can manage. MP3 is encumbered with patents and offers sound quality that’s inferior to other lossy audio formats. HTML has improved through major revisions, but it’s still a mess to validate. For that matter, we have formats like “English,” which lacks any spec and is a pile of kludges that have accumulated over centuries. Try finding support for supposed improvements such as Esperanto anywhere.
It’s a situation we just have to live with. The good enough hangs on, and the better has a hard time getting acceptance. Considering how unstable the world of data would be if this weren’t the case, it’s a good thing on the whole.
Photoshop’s native format, PSD, doesn’t get a lot of discussion. It’s Photoshop’s default format, and people use it for projects if only for that reason, so we really should know something about it. A lively place to start is “Fun Photoshop File Format Facts” on the Postlight blog. For serious investigation, look at Adobe’s specification. There’s also a short article on archiveteam.org, with some information about the format’s history.
NASA is using a format for online files, called MRF (Meta Raster Format), which is claimed to deliver images ten times as fast as JPEG2000 from cloud services when used with a compression algorithm called LERC. LERC is under patent by Esri, which says the technique is especially suited for geospatial applications and makes the algorithm “freely available to the geospatial and earth sciences community.” An implementation of MRF from NASA is available on GitHub under the Apache license, and an implementation of LERC is on GitHub from Esri.
New image file formats keep turning up, taking advantage of advances in compression technology. One of the latest is FLIF, Free Lossless Image Format. It claims to outcompress PNG, lossless JPEG2000, lossless WebP, and lossless BPG. Though it has only a lossless mode, it claims that “FLIF works well on any kind of image, so the end-user does not need to try different algorithms and parameters.”
The WebP image format has been around for about five years, but till recently it’s been mostly a curiosity. I last blogged about it in 2013, when it didn’t have very wide support. Since then most browsers have adopted it, and now Google+ is making more use of it (no surprise, since Google is the format’s principal backer). It promises smarter lossy compression than JPEG and smaller file sizes for the same image quality.
Google has been promoting the WebP still image format for some time, and lately Facebook has added its support. It’s hard to displace the well-entrenched JPEG, but it could happen. It supports both lossy and lossless compression, and Google claims it offers a significant advantage in compression over PNG and JPEG. Google says it’s free of patent restrictions; the container is the familiar RIFF. The VP8 lossy format is available as an IETF RFC; a specification for the lossless format is also available.
The container spec supports XMP and Exif metadata. Canvas width and height can be as much as 16,777,216 pixels, though their product is limited to 4,294,967,296 pixels. As far as I can tell it doesn’t support tiling, though, so partial rendering of huge images in the style of JPEG2000 may not be practical.
Chrome, Opera, and Ice Cream Sandwich offer WebP support, but not many other browsers do. Facebook’s offerings of WebP images have resulted in complaints from users whose browsers can’t read the format. The Firefox development team is starting to warm to it but hasn’t committed to anything yet. Internet Explorer hasn’t even reached that point.
It’s still early to make bets, but WebP increasingly bears watching. I’ve initiated a page for updates and errata for Files that Last with some updated information on WebP. (When I wrote the book, I couldn’t find the lossless spec.)