Nexus One's AMOLED screen only uses 16-bit color

[*LTD*]

http://www.neowin.net/news/nexus-on...m_campaign=Feed:+neowin-all+(Neowin.net+News)

http://www.displaymate.com/Nexus_One_ShootOut.htm

Nexus One's AMOLED screen only uses 16-bit color
By Benjamin Rubenstein

Since Google released the Nexus One, people have been ranting and raving about the amazing colors and clarity that its 3.7" AMOLED display outputs. While the Nexus One's colors do pop, the AMOLED technology used for this seemingly "superphone" is less than stellar. DisplayMate ran some tests and the results are nothing short of shocking.

Without going into too much technical jargon, the Nexus One's screen uses a PenTile pixel arrangement. This means that each pixel only contains two sub-pixels. In a traditional display, each pixel consists of three sub-pixels (red, green, and blue). The pixels on the Nexus One's AMOLED display only have a green, plus a red or blue on every other pixel. This isn't necessarily a problem, as the software can just use the red or blue from a nearby pixel, but it does put an extra strain on the software and can cause artifacts to appear on the screen.

DisplayMate points out that the above is irrelevant unless it affects the actual image quality. If a user can't tell the difference, then who cares? Unfortunately for the Nexus One, you can see a huge difference when comparing it to a standard LED display, such as the iPhone's. Here are some of DisplayMate's conclusions:

Nexus One's screen only uses 16-bit color with only 32 or 64 intensity levels - This is something that a high performance device should not have. A good screen typically has at least 18-bit color, giving a much larger number of intensity levels with clearer and more accurate colors. Green is present in twice as many pixels as red and blue. This gives green a much higher intensity than other colors.

Image quality is resolution scaling is bad - "Pictures and photographs from external sources, whether they be from digital cameras or web content are rendered poorly and inaccurately, with over-saturated colors, bad color and gray-scale accuracy, large color and gray-scale tracking errors, calibration errors, lots of image noise from excessive edge and sharpness processing, and many artifacts."

Peak white brightness is very low - This makes the display hard to read when outdoors, and nearly impossible in direct sunlight.

Poor calibration - "If the Nexus One display were an LCD it would rank among the worst displays we have ever seen in a shipping product." This could be due to the way the device was manufactured, or even due to the way the Android OS speaks to the display. Either way, the screen doesn't work well for images and web content.

More details are covered in the study and the bottom line conclusion is underwhelming. The Nexus One's screen, from an evolutionary standpoint, is a failure. AMOLED technology is the supposed to be the latest and greatest, not a step backward. Below are images that show how the Nexus One's screen performs next to the iPhone. Notice the image noise and that the dispaly's shortcomings are clearly present. For a phone that's supposed to be centered around eye candy, pictures, and web content, the Nexus One's screen is sure a letdown.

 

[rdowns]

Nexus One is dead™ [/*LTD*]

 

[*LTD*]

Nexus One is dead™ [/*LTD*]

Hehe . . .

Seriously, though, the more we learn about the Nexus One, the lousier of a device it seems. Typical Google BETA. Meanwhile Apple continues to build on a very solid mobile foundation.

The Nexus One isn't dead, but it ended up being a really lukewarm event all around. Once again, the problem is that Apple is competing in the same space, and like it or not everything will be compared to the iPhone, which means that odds are the comparisons won't be all that favourable or at the very least the big hoopla will die out sooner than expected.

 

[roadbloc]

I think we can all agree that the Nexus One was a call my bluff from Google to Apple.

 

[Abstract]

Green is present in twice as many pixels as red and blue. This gives green a much higher intensity than other colors.

Same with ALL digital photography: 2 x greens, 1 x red, and 1 x blue. Each camera pixel can only pick up 1 colour, and has to interpolate the values of the other 2 colours. Think about how much interpolation that requires, and yet how great the photos turn out, including the colour.

I don't think the display of this phone will be the limiting factor of any colour inaccuracies a person would see on this screen. The colour inaccuracies of a digital photo would be far greater than inaccuracies caused by the colour interpolation required of this mobile phone display.

Image quality is resolution scaling is bad - "Pictures and photographs from external sources, whether they be from digital cameras or web content are rendered poorly and inaccurately, with over-saturated colors, bad color and gray-scale accuracy, large color and gray-scale tracking errors, calibration errors, lots of image noise from excessive edge and sharpness processing, and many artifacts."

All of that is an exaggeration.

Again, digital photos only detect 1 out of 3 colours, and yet you don't see the hugely over-saturated colours, horrendous rendering, blah blah blah that this article mentions regarding this screen. If the screen colours look saturated, it's because of the settings chosen by t
HTC or Google.

Secondly, 99.99999% of all laptop screens ever produced are capable of displaying 16-million colours, but only by interpolating between the 2^18 (6-bit RGB, or 262,144 total colours) colours it's technically capable of displaying. I realize that interpolation is ALWAYS bad, but the large majority of people are actually used to seeing FAR more interpolation than you see here on this display, and yet it hasn't destroyed careers, ruined lives, or destroyed dreams, puppies, or rainbows.

Accordingly, the amount of interpolation required to turn 262,144 colours ---> 16-million colours FAR exceeds the amount of interpolation needed to turn 65,536 colours --> into the 262,144 that these mobile phone screens aim to display.

So while the screen has to interpolated colours upward, the amount required to match an 18 bit image isn't much.

....large color and gray-scale tracking errors,...

Uh....almost all the grayscale images you have ever seen are only capable of 256 different shades of gray. That includes nearly all black and white photography. The screen would easily, with NO error, be capable of accurately displaying the intended shade of gray. Doesn't matter whether your original photo was 24-bit, 18-bit, 12-bit....whatever.

Even super-high quality grayscale images are capable of displaying 65536 shades of gray, but I wonder why medical x-rays would be viewed on a Nexus One.

Poor calibration - "If the Nexus One display were an LCD it would rank among the worst displays we have ever seen in a shipping product." This could be due to the way the device was manufactured, or even due to the way the Android OS speaks to the display.

The article shows examples of a Nexus One screen with banding. Ok, but the main point of their article was that it was due to the poor screen technology. Then they add the last bit I quoted above (in bold). Sooooo...... is the problem the technology of the screen used by the Nexus One, or is it how the Android OS speaks to the display? They blame the screen technology through the entire article because.....well.....it probably gets more of a reaction from readers like you. It's a possibility, but I think the writer of this article knew he was writing sensationalistic crap and knows there's a good chance that he's wrong. That's why he wrote half a sentence that mentioned that it could be the Google OS. Perhaps he's hoping that you won't see it.

I'll use an example: Apple laptops. Some Apple laptops have exhibited the same types of banding ofer the years, so is it due to the 18-bit display and interpolation? Well, no it wasn't. After all, you didn't see it in every laptops, and all laptops interpolated colours so that they can show 16 million.

 

[kdarling]

Forget color resolution.

Going back to the iPhone screen (or any such older device) from a WVGA phone is almost painful.

The iPhone screen resolution looks quite blurry in comparison. I can still see every pixel on the iPhone, even with my older eyes.

 

[greygray]

I think we can all agree that the Nexus One was a call my bluff from Google to Apple.

Looks like we can all conclude with such an agreement.

 

[maflynn]

While I haven't been following the Nexus one religiously, so far I've not really heard any complaints regarding its screen.

While it may only use 16bit color, how different is that from Apple's MBP line which is incapable of displaying millions of colors and requires dithering.

I'd rather have a laptop that produced high quality images rather then a cell phone.

 

[*LTD*]

While I haven't been following the Nexus one religiously, so far I've not really heard any complaints regarding its screen.

While it may only use 16bit color, how different is that from Apple's MBP line which is incapable of displaying millions of colors and requires dithering.

I'd rather have a laptop that produced high quality images rather then a cell phone.

I think you're misunderstanding that particular issue (with the 13-inch MBP.)

 

[maflynn]

I think you're misunderstanding that particular issue (with the 13-inch MBP.)

How so?

btw, I have a 15" MBP and it is incapable of handling millions of colors and it dithers images.

 

[*LTD*]

How so?

btw, I have a 15" MBP and it is incapable of handling millions of colors and it dithers images.

There is no such thing as a 16 million (I assume you're referring to this figure) colour display. None has ever been made. Every display fakes the eye into seeing 16M colours and both a 16bit and 8bit display do that.

A 6-bit TN panel can show a total of 190 colours. Black, and 63 reds, 63 greens, 63 blues. The use of spatial placement of these colours yields 260,000 colours. Via the use of some temporal alterations of these colours, they can show 16.2 million colours in such a way that the human eye cannot detect. However, some screens clearly have issues that make the dithering (either spatial or temporal) more noticeable than it should be.

 

[mkrishnan]

While I haven't been following the Nexus one religiously, so far I've not really heard any complaints regarding its screen.

It does seem rather curious, when a phone has been in people's hands for some time, and they are content with a feature, and then someone points out some technical detail of how that feature works, and how it's obviously unacceptable. If the screen were obviously unacceptable, this person could have posted all the end-result complaints (bad scaling, color inaccuracy, etc) long before they knew why these things were happening.

OTOH I had an Axim with a 640x480 screen now some... six years ago? I still find the resolution on the iPhone quite satisfactory. It could be higher, sure, but it is hardly neanderthal.

 

[maflynn]

There is no such thing as a 16 million (I assume you're referring to this figure) colour display. None has ever been made. Every display fakes the eye into seeing 16M colours and both a 16bit and 8bit display do that.

A 6-bit TN panel can show a total of 190 colours. Black, and 63 reds, 63 greens, 63 blues. The use if spatial placement of these colours yields 260,000 colours. Via the use of some temporal alterations of these colours, they can show 16.2 million colours in such a way that the human eye cannot detect. However, some screens clearly have issues that make the dithering (either spatial or temporal) more noticeable than it should be.

There are 8bit panels that can display millions of colors and apple's dithering on their MBP line is quite noticeable, not just some screens but rather their entire laptop line is incapable of properly showing an image with millions of colors.

 

[thejadedmonkey]

Someone realized that the extreme dithering only happens in certain applications, and it was found to be linked to the programs themselves only displaying part of the full color gamut, and not the screen.

 

[gnasher729]

While it may only use 16bit color, how different is that from Apple's MBP line which is incapable of displaying millions of colors and requires dithering.

It _is_ capable of displaying millions of colours by using temporal dithering.

 

[maflynn]

It _is_ capable of displaying millions of colours by using temporal dithering.

No it isn't. I have plenty of examples that show substandard images because the dithering is incapable of accurately representing the images.

I use my MBP for photography and time in and time out, I see the difference when using the MBP w/o an external display and with.