The Difference Between UHD and 4K

I haven’t paid much attention to news surrounding ‘4K’ or Ultra-HD (UHD) video resolutions up until very recently. I’d largely ignored the topic until the Mac Pro’s were released in December and it became a topic of discussion on ATP much to Casey’s dismay.

The topic of 4K video has crossed my radar from time to time over the past 4 or 5 years, such as when Youtube announced their support for 4K video back in July of 2010. At the time I didn’t think much of this as there was hardly any 4K content out and even fewer ways to see it in 4K. I thought of this as Google being Google in their typical way of allowing their engineers to drive their product development despite the fact that few if any of their customers would use this feature.

As a part of my job, I am responsible for all digital content at a major trade show once per year throughout whatever convention center we’re at. The trade show has between 25,000–30,000 attendees each year which means I’m usually dealing with 30–50 screens spread out around the buildings all with different content on them. To a non-green building professional this content won’t excite you but nevertheless, our marketing department find new and fun ways to make my life difficult each year in terms of formatting etc.

Over the last few years however, things have progressively gotten easier as all of the displays we rent or are given through donations (we’re a non-profit) and the computers we rent from our AV vendors have unified around 1080P for resolution and HDMI connectors. I’m able to tell our marketing folks to “just make everything 1920 x 1080” and this works for 95% of our content. [1]

You’d be surprised as how many college educated marketing & design-related people are starting new jobs, are fully versed in using Adobe Photoshop, Illustrator, and InDesign yet have no idea what 4:3 or 16:9 means without further explanation. I’m going to risk sounding like an old man when I said I wish college professors were teaching these people practical skills. [2]

Back to the main subject: 4K vs UHD. Recently I have seen these terms interchanged and I assumed they meant the same thing. They do not. Dylan Seeger at VS Forum writes:

Like 2K, 4K is a professional format used on the commercial side of video production most often seen by everyday consumers at commercial movie theaters equipped with the latest digital projectors. Unlike UHD, 4K has a different native aspect ratio. A true 4K image (4096x2160) has an aspect ratio of 1.9:1, while a true UHD image (3840x2160) is 1.78:1. We can see here that a 4K panel is actually wider by 256 pixels. This is a trivial number and doesn’t do much in terms of overall resolution or clarity of the image. I’m fairly certain that this minimal difference in resolution is what’s fueling many of us to call UHD “4K.”

This 256 horizontal pixel difference causes at least one major issue when dealing with consumer content. The problem is that almost all television content is presented in a 1.78:1 aspect ratio. If we were to view this content on a true 4K display, we would see black bars on the left and right side of the display to keep that original aspect ratio intact. While enthusiasts understand the reasoning behind this, most everyday viewers would find their TV content annoyingly masked with black bars, very similar to how they find black bars on their 1080p televisions annoying while viewing ’scope films. This is one of the main reasons for choosing 3840x2160 as the next-gen consumer resolution. It makes sense to keep that 1.78:1 aspect ratio as most content made for broadcast TV is presented this way.

True 4K is the resolution specified by the DCI (Digital Cinema Initiative) commercial standard. This is another area where UHD and 4K differ. Much like Blu-ray is the 1080p standard for encoding and presentation, 4K has its own set of standards that the DCI dictates. These standards are high end, resulting in exemplary image quality. While it isn’t totally clear yet what kind of video encoding standards the new UHD video format will use, all rumors point to sub-par encoding. DCI 4K uses JPEG2000 video compression, up to 250Mbps video bitrate, 12-bit 4:4:4 video, and a much wider color gamut. HDMI 2.0 will most likely dictate the standards for UHD Blu-ray (or whatever they decide to call it). Unfortunately, HDMI has very little left to give as an interconnect standard. As a result, there is no way to transport the amount of information needed to exceed or even match the 4K DCI standard. Those in the know are under NDA (non-disclosure agreements), which means we won’t know the specifics for at least another month or two. Rumors point to 10-bit 4:2:2 video for UHD video content at 24 frames per second and a doubling of the throughput to support higher bitrates.
Reading the entirety of Dylan’s article is worth it to understand the differences between the two formats and the implications of those differences. This was the first time that I had seen those differences outlined in detail and thought it best to spread the word.


  1. I still get curveballs thrown at me such as sponsor supplied videos given to me in 4:3 aspect ratios in WMV format or those awful 29:8 aspect ratio screens going into the exhibit halls in Moscone North and South.  ↩

  2. It would also help if they knew HTML and to never copy & paste content out of Microsoft Word into a WYSIWYG editor in a CMS.  ↩

Year In Cities 2013

It is my fifth year of keeping track of which cities I've slept in over the past year. I've done this for 2009, 2010,2011, and 2012. Credit for this idea goes to Jason Kottke who I noticed doing this first and liked it, so I decided to do it too.

The rules: One or more nights were spent in each place. Those cities marked with an * were visited multiple times on non-consecutive days

Alexandria, VA*
Warrenton, VA*
Wirtz, VA*
New York City, NY
Philadelphia, PA

I fell from a total of 7 last year back down to 5 this year. Less travel because of building & moving into the house.

"Worker Deaths Raise Questions at an Apple Contractor in China"

Another inflammatory headline from the New York Times:

"Apple supplier"? Really? Pegatron makes notebooks, netbooks, desktop PCs, tablets, other mobile devices, motherboards, graphic cards, cable modems, set-top boxes, phones, game consoles, mp3 players, e-readers, and a host of other devices for many companies - but all the New York Times can focus on is that Apple buys stuff from them so somehow this is an Apple problem? Apple is probably the only customer they have who holds them responsible in any way. Mentioning Apple in the headline is an easy way to get clicks. Android apologists will share it and then go on to explain that this is why they don't use Apple products, even though they use devices made in the same facility, for a company that does less to ensure safe working conditions than Apple does.

House Status: Pre-closing walk through edition.

We did our final walk-through of the house today prior to closing. We went around and inspected every inch of every wall, floor, ceiling & surface to point out things that need to be touched up, fixed, etc. It took about 2 hours to do, and overall we're very happy with the progress. You'll notice all of the blue painter's tape marks throughout - that's part of what we did today on the walk-through. Steffanie had a lot of fun picking out things with the tape she wanted them to touch-up or fix. If you ever want your house covered in blue painters tape, go buy a roll and she'll be glad to come do it. (Really, she very much enjoyed this.)

The story of out-of-control debts and deficits is just plain wrong. US deficits have fallen in the past four years

Dean Baker, at The Guardian writes:

Republicans are delusional about US spending and deficits

Contrary to the widely repeated stories of out-of-control deficits and spending, deficits have plunged in the last four years falling from 10.1% of GDP in 2009 to just 4% of GDP in 2013. The Congressional Budget Office projects the deficit to be just 3.4% of GDP in 2014. The latest projections show the debt-to-GDP ratio falling for the rest of the decade.

Nest 'Nestifies' A Smoke Detecter

I had read news that Nest was probably going to release something in this segment of the market. Given that we are mere weeks away from moving into our new home, and I'm planning two install two Nest Thermostats as it is, the announcement from Nest this morning has me very excited.

Nest Protect

Safety shouldn't be annoying. The Nest Protect smoke and carbon monoxide (CO) alarm quiets down when you wave - no more swinging towels or brooms - and messages your phone when its batteries run low. Nest Protect speaks with a human voice, telling you where and what the danger is, and gives you a friendly Heads-Up before turning on a loud alarm.

A few points that I found interesting:

  • They have both battery and wired versions
  • If you also have Nest Thermostats, the Nest Protects will share information with them.
  • Information shared can do things like turn off the furnace if it detects CO2, or motion data to assist with Nests learning.
  • Sends data to its iOS application
  • You can wave your hand near the Protect to signal for it to turn off in the event the smoke is from a source you're aware of.
  • At night, it can emit low light based on its motion sensor to help light the room in the event the lights are out (presumably so you don't trip over things on your way to the bathroom in the middle of the night without having to wake up your spouse.).