Apple CEO Tim Cook talks color quality at Goldman Sachs conference

Apple CEO Tim Cook

Apple CEO Tim Cook spoke at Goldman Sachs’ Technology and Internet Conference yesterday. He touched on a wide range of topics from what Apple plans to do with its cash horde to the state of its retail operation. When it came to a question about making lower cost products, Tim used display quality to help make a point about creating great user experiences:

The truth is, customers want a great experience and they want quality and they want that a-ha moment each time that they use the product, and that’s rarely a function of any of those things.

If you look at displays, some people are focused on size. There’s a few other things about the display that are important. Some people use displays, like OLED displays, the color saturation is awful. And so if you ever buy anything online and you want to really know what the color is as many people do, you should really think twice before you depend on the color of the OLED display. The Retina display is twice as bright as an OLED display. I only bring these points up to say there are many attributes to the display, and what Apple does is sweat every detail.

He makes some fair points here. If a display is not bright enough to view in all conditions, not efficient enough to get you through a whole day or accurate enough to display your favorite content, the experience of the whole device suffers. Choosing the right display technology is certainly a critical part of the design process.

OLED technology’s power consumption and saturation issues have been well established already. What I find most interesting in Tim’s comments is the idea that high color saturation is intrinsically a bad experience. It certainly has been that way so far but the difference between a great color experience and the gaudy oversaturation of today’s OLEDs is in exactly the kind of implementation details he’s describing above.

OLED and emerging LCD technologies, like quantum dot displays, can actually show a much wider range of colors than today’s devices– over 40% more of the color that our eyes can detect. This means that, when paired with the right content, high saturation displays can more accurately reflect the world we see around us resulting in a more lifelike, immersive experience.

But how do we get wide color gamut content into consumers hands?

It’s a lot like the chicken and egg/content and technology dilemma facing 4K TV makers with two key differences- wide color gamut can be delivered with no change in file size and there’s plenty content out there already. As an example, movies have been shot for decades on media, both film and digital, that has a much wider color gamut than your TV does today. Much in the same way that 4K TV’s can upscale HD video, it’s also relatively easy to manage the color on a device to make it backwards compatible with today’s content.

OLED implementers have thus far been content to take advantage of the extra pop that added color saturation provides when comparing devices on a store shelf. They’ve left a tremendous amount of overall ecosystem value on the table. It’s possible to deliver video in cinema-level color quality to mobile devices, to offer developers the tools to take full advantage of a wider color palette and to implement accurate color management for existing content. Wide color gamut is ready now, it’s just waiting for the right device maker to come along and put all these pieces together to perfect the experience. 

Color at CES 2013

I’m just wrapping up my visit to CES and it’s been interesting year for display technologies. Amid all the noise about 4K, OLED and 4K-OLED, color performance seems to have quietly worked its way into the conversation. I can’t recall ever having so many relatively technical conversations about color with booth reps from major consumer electronics manufacturers at a CES. It nearly started feeling like a visit to DisplayWeek, that is until I ran into some of the weird, only-at-CES iPhone cases

Color Your World CES 2013

I bet we’ll see more color talk next year, especially as 4K content delivery mechanisms and standards begin to mature. In the meantime, these are some of the color-related display stories that caught my eye this week:

Wide gamut content delivery

Sony’s 4K content delivery plans have been one of the most talked about topics here at CES. Less mentioned was Sony’s inclusion of wider color gamut in their standard. Sony reps that I talked to said that both the 1080P Blu-ray disc-based “mastered in 4K” and pure 4K delivery methods would include a wider color gamut. They were not ready to release specifics on gamut size or whether it would meet existing standards like DCI-P3. Still, bringing “expanded color showcasing more of the wide range of rich color contained in the original source” is a move in the right direction for wide gamut.

Color accuracy

Technicolor showed off a color certification program that they hope will incentivize display makers to improve the color accuracy of their panels. Displays that meet or exceed Technicolor’s color specs will get a badge and a copy of partner Portrait Display’s Chroma Tune software, which dynamically controls color gamut to match the application you are using. This means if you open Photoshop on a device with an Adobe RGB 1998 capable display, you’ll get the full, wide gamut. But, if you switch over to watch a YouTube video in your browser, the software will limit the display to rec.709 for the most accurate experience. The advantage was well demonstrated by their e-commerce demo, where a pair of shoes were more accurately depicted on a certified display:

Technicolor's ecommerce Color Certification demo at CES 2013. The color certified laptop in the middle of the frame more accurately shows the color of the shoes.

Technicolor’s ecommerce Color Certification demo at CES 2013. The color certified laptop in the middle of the frame more accurately shows the color of the shoes.

Like Sony’s upscaling effort, this kind of technology could help drive wide color gamut adoption by making today’s content compatible with newer displays.

Huge tablets

Panasonic 4K Tablet with sRGB color gamut at CES 2013

Panasonic’s 20 inch 4K/sRGB tablet

Several companies at the show introduced devices in a new class- the 20-plus inch tablet. While there were a lot of hokey multi touch gaming demos (are you really going to play poker with 4 smartphones and a 27″ screen instead of a deck of cards?), the content creation stuff Panasonic showed actually made me think the new form factor shows real promise as a professional tool.

Their tablet, which measures 20 inches on the diagonal, features a 4K IPS panel that covers 100% of the sRGB color gamut standard. Having such a a large canvas with high resolution, accurate color and multi-touch could be great for creative pros like photographers and architects.

Are tablets up to the task of accurate color testing?

Finally getting around to posting a follow-up to a follow-up to John The Math Guy’s recent series on color gamut size, colorblindness and tablet displays. I thought I might be able to at least shed a little more light on his question about the differences in color accuracy between some of these devices.

In his testing, John found no statistically significant difference in scores among different people taking the EnChroma colorblindness test on different devices. I found this somewhat surprising since, in my experience, even tablets with similar color gamuts tend to show colors with very different levels of accuracy.

iPad mini color gamut and Gretag Macbeth colors against sRGB in CIE1976

To show what I mean by that, I measured how two different tablets show the colors found in the Gretag Macbeth color checker chart.Nexus 7 color gamut and Gretag Macbeth colors against sRGB in CIE1976

As you can see, the iPad mini and Nexus 7 each produce very different colors, even for those colors that are actually inside their gamuts.

For example, even though the iPad mini has enough gamut coverage to accurately display the Gretag chart’s deepest blue, it cannot do so without distorting the image in another way. This is because of data in the underlying image standard- most content today is encoded in the sRGB standard. If the iPad were to show that Gretag blue correctly, it would not have enough color saturation headroom left over to show you a different color if a deeper blue, say right at the bottom of the sRGB triangle, were called for.

A good real world example of this can be found in the picture below of my bloodhound, Louisa, racing down the beach at Carmel, CA. The middle of the sky in this image is right on the edge of the iPad’s color gamut, very similar to the Gretag blue in the charts above, while the deepest blues found in the ocean fall outside the iPad’s gamut.

Out of gamut colors at beach

If the iPad were striving for accuracy at all costs, it might map both colors right on top of each other at the edge of the gamut. There’d be no visible difference between the two in this case and the quality of the image would suffer but at least the sky would be accurate. In order to avoid this scenario, the designers of these devices have decided to compromise on accuracy so they can show a full range of color differences to the user.

They do this by remapping colors inward, away from the edges of the gamut, effectively compressing the gamut even further so that otherwise out-of-gamut colors can be seen. This is a good solution given the gamut limitations of the device since it results in more pleasing, if less accurate images.

As newer devices trend towards wider color gamuts this kind of compromise should become a thing of the past. In fact, tablet designers may be working on the reverse issue- how to avoid oversaturating images that were encoded for smaller gamuts.

Great, how does this relate to colorblindness again?

iPad mini vs Nexus 7 color accuracy comparison in CIE 1976

iPad mini vs Nexus 7 color accuracy comparison in CIE 1976

Taking another look at the Gretag results from the two devices plotted on top of each other, there clearly are major differences. But, in the reds and greens, two colors associated with a common form of color blindness, the devices are relatively close. So, the simple answer may just be that colorblindness tests do not require pinpoint accuracy to be effective, at least as basic screening tools.

Shopping for a tablet this holiday season? Don’t forget to look at color performance

If you have been researching the perfect tablet to give to a loved one this holiday season, you’ve probably read a lot about display quality. Tablet display size, resolution and aspect ratio have been discussed at length this year, which is really no surprise, since the quality of the display has the biggest impact on how we enjoy content on these devices.

What is surprising though is that color performance, one of the biggest differentiators among the current crop of tablet displays, has been largely glossed over by the mainstream gadget press.

The Verge’s tablet comparison tool, for example, gives great info about pixel density, aspect ratio and touch capabilities, but color performance is nowhere to be found:

Color is being ignored in spite of the fact that there are tremendous differences in the color performance of each of these devices that directly impact the consumer experience on each.

So why are we overlooking a feature that, unlike many of the features we focus on these days, presents a real difference between devices?  I see a couple reasons. First and foremost, thanks to Apple’s marketing of the Retina display, pixels-per-inch has become the spec du jour in today’s device wars.  Device makers are focusing their marketing efforts on pixel count above anything else.

Aside from current trends, I believe there’s also a macro reason to why color has been left out: color performance is just hard to compare. There is no universally accepted spec that can sum up color performance across devices.

Take the three popular tablets above. We could add a “color gamut” row to the chart, measuring against sRGB, which would look like this:

From this information, a shopper could gather that the Nexus 7 and Kindle Fire HD have about the same color performance and both outdo the iPad mini. That is an accurate assessment, but it’s not the whole story. If we look at those color gamuts plotted in CIE 1976, some important nuances become apparent.

By measuring the percent of sRGB, we know how much of that overall color standard the device can reproduce.  However, displays usually produce more of one color than another and that information is completely lost with this measurement.  The Nexus and Kindle have significantly deeper blue than the iPad mini, most likely due to a narrower blue color filter like the one found in the third and fourth generation iPad. This accounts for most of the difference in sRGB coverage between the iPad mini and the other two devices.

Take a look at the other two primaries and it gets more interesting. In the image on the right that zooms in on green, we see that the Kindle Fire has the deepest green of the three, followed by the iPad mini and the Nexus.

For reds, though, it’s different again, with the Nexus having the deepest reds followed by Kindle and then iPad.

If we ever want to make color performance a real differentiator in consumer choice, we need to develop a new universal standard to easily compare color across devices, taking into account all of these nuances.

Color is a complex story to tell, but small differences in color performance are just as noticeable to consumers as pixel density in everyday use. Next time you find yourself at a retailer who carries all three devices, try googling test patterns and look at the differences. You might be surprised.

Gizmodo: Tech’s New Most Meaningless Spec: PPI

source: Gizmodo

Adrian Covert of Gizmodo has an interesting piece looking at the gadget industry’s recent obsession with high PPI displays. With devices like the HTC DNA pushing resolution well past 300 PPI, electronics makers may be turning PPI into the next overhyped marketing stat, just like contrast ratio is for the TV industry and megapixel is for the digital camera.

Adrian gets to the heart of the problem:

There are plenty of ways to make a better-looking display. But we’ve reached the point in the pixel density wars where higher figures have stopped automatically equating to improved performance for users. Any grandstanding about pixel density, from here on out, now is mostly just marketing fluff.

We tend to agree, and color performance is probably the display feature with the most room to improve. The best LCD smartphones on the shelves right now can show you more pixels than your eye can detect, but can only show you about a third of the colors you can see. If electronics makers want impactful feature improvements for new devices, color performance is where it’s at.

iPhone 5 color saturation claims

Display improvements were once again featured at yesterday’s Apple keynote event. The most obvious improvements may have been the larger display and thinner form factor but most interesting to dot-color are the color claims.

Just like the new iPad, Apple claims that the iPhone 5 can display “44% more color saturation.”

Apple SVP of Worldwide Marketing Phil Schiller talks color saturation at the iPhone 5 keynote

Let’s do some simple math to see how the iPhone 5 stacks up against older iPhones and last week’s color performance claim from Motorola.

  • iPhone 4S IPS LCD: 50% NTSC color gamut (CIE 1931)
  • iPhone 5 IPS LCD: 50% * 144% = 72% NTSC color gamut (CIE 1931)
  • Motorola Droid Razr Maxx HD AMOLED: iPhone 4S (50%) * 185% = 92.5% NTSC (CIE 1931)

So Motorola is still king of the fall 2012 smartphone color saturation, based solely on marketing claims. That said, I wouldn’t be surprised if they updated their marketing to say that the Droid Razr Maxx HD offers 28% more color saturation than the iPhone 5 once it hits store shelves in a couple weeks. I plan to measure all of the announced devices to verify these marketing claims, but for now, this is all we have to go with.

Apple also claimed to be able to match the sRGB standard used in TV and movies. With the addition of the iPhone 5, nearly all of Apple’s flagship products (with the exception of the MacBook Air) now meet this standard. This means content should look very consistent across all Apple devices and may open up the possibility for serious content creation apps in iOS.

It also means we’re only just now catching up to an average CRT display from circa 1990, as the sRGB standard is based on the capabilities of phosphor materials used in CRTs. And even still, the new displays are only covering about 35% of the range of colors a human eye can see. There’s still plenty of room for improvement in display color performance (as well as updated content delivery standards, but that is a whole different post).  Hopefully if we keep on this kind of pace with display enhancements, next year we’ll start to see a push beyond the limits of last century’s color standards.

We’re using the long outdated CIE 1931 color space and NTSC 1953 gamut standards here since this is clearly Apple’s reference when they claim 44% more saturation and sRGB coverage. 50% * 1.44 = 72% and 72% of NTSC 1953 gamut in the CIE 1931 color space is also called the sRGB color gamut.

It is not clear which color space Motorola is referencing; we are assuming CIE 1931/NTSC 1953 for ease of comparison.

Beyond Retina: holiday releases see device makers move beyond PPI in display marketing efforts

Over the past couple weeks we’ve seen device manufacturers start to gear up for the holiday season, highlighted by big product announcements from Nokia, Motorola and Amazon. It’s been especially interesting for me to follow how these companies market the most important part of the device – the screen. While pixel per inch still seems important, device makers have moved into more nuanced territory, highlighting deeper features like reduced reflectivity, improved touch sensitivity and color saturation.

Here’s a roundup the most interesting new display features in this holiday’s hottest devices:

Nokia was first up this week with a new crop of Lumia handsets, the 920 and 820. They introduced a slightly larger display for the flagship 920 (now 4.5 inches compared to last year’s 4.3” Lumia 900), touted a new level of touch sensitivity that even works with gloves and claimed 25% more brightness than rival phones. Also of note, they switched from AMOLED to IPS LCD. It’s not yet clear if cost/supply issues or performance drove this switch. It may be that they preferred the brightness and power efficiency of LCD.

Right on the heels of Nokia, Motorola and Google announced a group of new smartphones, led by the Droid Razr Maxx HD. The company described the new Super AMOLED display as having “85% more color saturation than the iPhone 4S, so everything is in lifelike detail.” It’s great to hear them talking about the value of color performance. Hopefully they’ve included some color rendering optimization to artfully take advantage of that extra saturation without overdoing it.

Amazon followed up yesterday with several new devices across their entire Kindle line-up and a surprisingly technical presentation that took a deep dive into the LCD film stack. They showed how a reduced air gap between the touch screen and LCD surface can reduce screen glare, suggesting the new Fire HD has reduced glare by 25%. Also, in a move that’s sure to please LCD film manufacturers like 3M, they discussed the value of better polarizing filters for achieving wider viewing angles without color distortion.

Of course, everyone still compared their products to the now year old iPhone 4S, so it will be interesting to see how these features stack up to whatever Apple introduces next week.  We’ll be sure to pick up a few of these devices and run them through their paces to see how the marketing-speak stacks up to real world performance.