Google Nexus One versus Motorola Droid Display Shoot-Out

Dr. Raymond M. Soneira

President, DisplayMate Technologies Corporation

Copyright © 1990-2010 by DisplayMate Technologies Corporation. All Rights Reserved.

This article, or any part thereof, may not be copied, reproduced, mirrored, distributed or incorporated

into any other work without the prior written permission of DisplayMate Technologies Corporation

Series Overview

This is Part V of a comprehensive multi-part article series with in-depth measurements and analysis for the OLED and LCD displays on the Google Nexus One , the Apple iPhone 3GS and the Motorola Droid . It is produced as a collaboration between DisplayBlog and DisplayMate Technologies . We will show you the good, the bad, and also the ugly unfinished rough edges and problems lurking below the surface of each of these displays and display technologies. Each article will be introduced and discussed on DisplayBlog by Jin Kim, followed up with a detailed technical analysis and measurement data on the DisplayMate website. Part I deals with the Google Nexus One Part II with the Apple iPhone 3GS , and Part III is a detailed point-for-point Shoot-Out comparison between the displays on Nexus One and the iPhone. Part IV deals with the Motorola Droid and Part V is a detailed point-for-point Shoot-Out comparison between the displays on the Nexus One and the Motorola Droid.

Introduction

There have been lots of articles and discussions comparing the iPhone, Nexus One and Motorola Droid displays, but no one has yet done anything more than superficial eye ball commentary. This article series is an in-depth scientific analysis of these displays.

The Nexus One display is distinctive and unusual in several respects: it is an Organic LED display, which is an emissive display technology, whereas most mobile devices have an LCD display, which uses a static backlight behind the panel. The screen is 3.7 inches diagonally and has a high-resolution high-density 800x480 pixel display with a screen Aspect Ratio of 1.67. The Motorola Droid has a traditional LCD display with a White LED backlight. The screen is 3.7 inches diagonally and has a high-resolution high-density 854x480 pixel display with a screen Aspect Ratio of 1.78, which is identical to standard 16:9 widescreen displays, such as HDTVs, which have an Aspect Ratio of 1.78. Both phones use the Google Android OS. The Nexus One was tested with version 2.1 and the Motorola Droid with version 2.0.1. We found so many image and picture quality problems and implementation issues with the display on the Nexus One that it will be especially interesting to see whether the Motorola Droid, which has the same Android OS, suffers from the same problems and issues, or whether Motorola did a better job of engineering the display hardware, firmware and software than Google and HTC.

Important Note for Android OS 2.1 Upgrade

The tests for this article were performed using the original 2.0 Android OS for the Motorola Droid. Afterwards, when the Droid was upgraded to version 2.1, the Gallery (the principal image viewer for the phone) surprisingly downgraded to 16-bit color from its original full 24-bit color in version 2.0. Fortunately, version 2.1 of the Android Browser on the Droid still delivers full 24-bit color. Image Scaling for the Gallery (which adjusts images so they fit the native resolution of the display) went from Excellent in version 2.0 to Poor in version 2.1, the same as for the Browser (both versions). As a result the beautiful screen shots for the Droid in Figure 1 in Part IV now look exactly like those for the Google Nexus One on the left. Overall, the Droid still delivers substantially better picture quality and accuracy than the Nexus One. Presumably these errors, which affect both the Droid and the Nexus One will be fixed in a future software upgrade, so the Droid will at some point return to its original excellent 24-bit color and scaling. The quality of the 24-bit color and scaling for the Nexus One remains to be seen…

Click Here to Compare Before and After Upgrade Images. Google acknowledges these problems for all 2.1 Android phones including the Nexus One and Motorola Droid. The next major release of the Android OS will fix these issues and provide full 24-bit color and improved scaling.

Click Here to Read the Google and Cooliris Statements.

The inner details of the display technologies are very interesting, but our concern here is to evaluate the actual image and picture quality that they deliver, so we don’t really care how they do it, as long as they do it well. None-the-less with the measurements and analytical test patterns we will learn quite a bit about how they work.

Shoot-Out Overview

First we provide a summary of the Graphical Data from Part I and Part IV , next a comprehensive point-for-point color coded Comparison Table , and then finish with Suggestions and Conclusions for Google and Motorola .

Graphical Data

Below is the Graphical Data for the Nexus One and Motorola Droid from Parts I and IV.

For details, measurements, explanations and in-depth analysis see Part I devoted to the Google Nexus One and Part IV devoted to the Motorola Droid.

Figure 1 shows the Color Gamuts and White Points with the sRGB / Rec.709 Standard for computer images, photos and video.

Figure 2 shows the Intensity Scales for the Nexus One and Motorola Droid and a Standard Gamma of 2.2.

Figure 3 shows the light spectra for the Nexus One and Motorola Droid.

Figure 1. CIE Chromaticity Diagram with Color Gamuts and White Points Figure 2. Intensity Scales and Standard Gamma

Figure 3. RGB Spectra for the Nexus One and Motorola Droid

Nexus One and Motorola Droid Display Shoot-Out Comparison Table

Below we compare the data on the Nexus One and Motorola Droid from Parts I and IV.

For details, measurements, explanations and in-depth analysis see Part I devoted to the Google Nexus One and Part IV devoted to the Motorola Droid.

Note that we are testing and evaluating the displays on the Nexus One and Droid with whatever hardware, firmware, OS and software are provided by Google and HTC for the Nexus One and Motorola for the Droid.

Google Nexus One Motorola Droid Comments Overall Assessment Unfinished Prototype Eventually Good Excellent Display DisplayMate Award The Motorola Droid LCD display is the finest mobile display we have tested. The Nexus One display still needs a lot of work to deliver a high quality picture Display Resolution 800 x 480 pixels 854 x 480 pixels Both displays have comparable screen pixels Total Number of Sub-Pixels 0.77 Million Less Sharp 1.23 Million Sharp The Nexus One has only 2 sub-pixels per pixel instead of the 3 used in most other displays Displayed Color Depth 16-bits on-screen Browser and Gallery Full 24-bits Browser and Gallery 16-bits produces false contouring and green-magenta tinted gray scales Image Scaling to Fit the Screen Poor for Browser Poor for Gallery Poor for Browser Excellent for Gallery Rates freedom from scaling artifacts and noise The Android Browser does this poorly Viewing Tests Gaudy Images Photos and Videos have too much color and too much contrast Excellent Images Photos and Videos have accurate color and accurate contrast The Viewing Tests examined the accuracy of photographic images by comparing the displays to a calibrated studio monitor. Overall Factory Calibration Poor Very Good Rates color and gray scale tracking and accuracy Poor means RGB primaries irregularly balanced Maximum Brightness or Peak Luminance 229 cd/m2 Relatively Low 449 cd/m2 Excellent Very important for a mobile device because of the typically high ambient light Black Level Brightness or Black Luminance 0.0035 cd/m2 Outstanding 0.165 cd/m2 Good for Mobile Only important only for low ambient light, which is seldom the case for mobile devices Contrast Ratio for Low Ambient Light 65,415 Outstanding 1,436 Very Good Dynamic 2,721 Only relevant for low ambient light, which is seldom the case for mobile devices Don’t confuse these values with inflated specs Screen Reflectance of Ambient Light 15.5 percent Relatively High 12.1 percent Average The most important spec for a mobile display because of the typically high ambient light. Nexus One reflects 28 percent more than the Droid Contrast Rating for High Ambient Light 15 Very Low 37 Very Good This Contrast is very important for a mobile device because of the typically high ambient light Dynamic Color and Contrast Yes Yes Best picture quality and accuracy is with No Should be an option to turn on and off Color Temperature 8870 degrees Kelvin Too Blue 6752 degrees Kelvin Close to D6500 D6500 is the standard for most content and necessary for accurate color reproduction White Point Chromaticity u’=0.1871 v’=0.4508 u’=01946. v’=0.4680 CIE 1976 Uniform Chromaticity Coordinates Color Gamut Poor - Too Large See Figure 1 Excellent See Figure 1 sRGB / Rec.709 is the standard for most content necessary for accurate color reproduction Color Saturation Too High Excellent On the Droid the colors in images, photos and videos are accurately reproduced Intensity Scale and Image Contrast Mostly Too High and Very Irregular Very Good The Intensity Scale controls image contrast needed for accurate image reproduction. See Figure 2 Gamma for Intensity Scale 1.82 to 2.55 Very Irregular 2.24 Close to Standard Gamma of 2.2 is the standard and needed for accurate image reproduction. See Figure 2 Brightness Decrease with 30 degree Viewing Angle 28 percent decrease to 166 cd/m2 Large for OLED 64 percent decrease to 160 cd/m2 Very Large Screens become less bright when tilted Both displays are equally bright at 30 degrees Droid behavior is typical for LCDs Black Level Increase with 30 degree Viewing Angle Visually Insignificant Not Measured 88 percent increase to 0.31 cd/m2 An increase contributes to image wash-out Droid behavior is typical for LCDs Contrast Ratio with 30 degree Viewing Angle Extremely High Not Measured 280 is Low Dynamic 516 A measure of screen readability when tilted Droid is still fine for text but images affected more Color Shift with 30 degree Viewing Angle Δ(u’v’) = 0.0262 7 times JNCD Δ(u’v’) = 0.0020 ½ times JNCD JNCD is a Just Noticeable Color Difference Droid has no noticeable color shift with angle Power Consumption at Maximum Brightness 0.91 watts 0.87 watts Both about 1 watt Power Consumption for the same Peak Luminance 229 cd/m2 0.91 watts 0.54 watts LCD with LED backlight is more efficient Power Consumption for Black 0 watts 0.46 watts OLED is zero because it is emissive Droid Dynamic Contrast reduces power for Black

Suggestions and Conclusions:

Below are the suggestions and conclusions for the Nexus One and Motorola Droid from Parts I and IV.

DisplayMate Technologies specializes in advanced mathematical display optimizations and precision quantitative and analytical scientific display factory calibrations to deliver outstanding image and picture quality and accuracy while increasing the effective visual Contrast Ratio of the panel and producing a higher calibrated brightness than is achievable with traditional calibration methods. We can also make lower cost displays look almost as good as more expensive higher performance panels. These articles are a brief introductory critical analysis. Our optimizations correct these deficiencies and much more. If you are a display or product manufacturer and want to turn a standard panel into a spectacular one Contact DisplayMate Technologies to learn more.

Suggestions for Google:

1. Eliminate the primitive 16-bit display interface and fix the Browser, Gallery and other applications.

2. The White Point is too blue, lower it to D6500, which will improve color accuracy, slow the aging of the Blue OLED, reduce power consumption, and improve battery run time.

3. Improve the factory display calibration to correct the large color and gray-scale tracking errors and the irregular and non-standard display contrast and Gamma.

4. The color saturation of the display is way too high. You can trade this excess color saturation to boost the screen brightness by adjusting the software color calibration matrices. This will also improve the color accuracy of the display.

5. Take full advantage of the OLED display: the ambient light sensor now just controls the screen brightness. You should also use it to control the gamma, color gamut, color saturation, and edge enhancement so that in low ambient light the display delivers beautiful and accurate image and picture quality, but as the ambient light increases slowly turn up these parameters to counter-balance the washed out appearance of the images in bright ambient light. Also add a display Vivid or Pizzazz control because some people prefer punchy images and pictures, while other people do not.

Suggestions for Motorola:

Keep up the good work… To make your displays even better follow the detailed comments and recommendations above and in greater detail in Part IV. Also ask Google to fix the poor image rescaling and its 16-bit implementation in the Browser and possibly other Android OS applications.

Nexus One Conclusion: The Nexus One Display Looks Like a Prototype

The Nexus One OLED display has many spectacular qualities, but it is also loaded with lots of rough edges, hasty unfinished beta display drivers and Android software including principal applications like the Browser and Gallery, poorly implemented image processing, poor system integration together with sub-standard factory display calibration. It really looks and behaves like a prototype for a very nice future display, not a finished production display for a world class mobile device that Google markets it to be. It will be interesting to see the degree to which existing units will be corrected and improved with software updates.

Motorola Droid Conclusion: Excellent Mobile Display wins two DisplayMate Best Video Hardware Guide Awards

The Motorola Droid is an excellent mobile display with just a few comparatively minor shortcomings. In terms of image and picture quality it comes closer to a high quality computer monitor or HDTV than any other mobile display we have tested – all the more impressive because mobile displays operate under challenging size, power and cost constraints. In fact, the image and picture quality and accuracy on the Droid is actually better than in most computer monitors and HDTVs (but smaller, of course). The screen is very bright and very sharp, has excellent color and gray scale accuracy, and has very good Contrast and readability under both dim and bright ambient light. For these reasons we have awarded the Motorola Droid the DisplayMate Best Video Hardware Guide Award for both Smartphones and the entire Mobile Display category.

For Additional Details, Measurements, Explanations and in-Depth Analysis:

Read Part I devoted to the Google Nexus One and Part IV devoted to the Motorola Droid. Part II is devoted to the Apple iPhone 3GS.

Special Thanks to Jay Catral of Konica Minolta for visiting the DisplayMate Lab and bringing the CS-2000 Spectroradiometer to measure the Spectra and the very dark Black Luminance of the Nexus One. And Special Thanks to Konica Minolta Sensing for loaning us the CS-2000 and sending Jay Catral.

About the Author

Dr. Raymond Soneira is President of DisplayMate Technologies Corporation of Amherst, New Hampshire, which produces video calibration, evaluation, and diagnostic products for consumers, technicians, and manufacturers. See www.displaymate.com. He is a research scientist with a career that spans physics, computer science, and television system design. Dr. Soneira obtained his Ph.D. in Theoretical Physics from Princeton University, spent 5 years as a Long-Term Member of the world famous Institute for Advanced Study in Princeton, another 5 years as a Principal Investigator in the Computer Systems Research Laboratory at AT&T Bell Laboratories, and has also designed, tested, and installed color television broadcast equipment for the CBS Television Network Engineering and Development Department. He has authored over 35 research articles in scientific journals in physics and computer science, including Scientific American. If you have any comments or questions about the article, you can contact him at dtso.info@displaymate.com.

About DisplayMate Technologies

DisplayMate Technologies specializes in advanced mathematical display optimizations and precision quantitative and analytical scientific display factory calibrations to deliver outstanding image and picture quality and accuracy while increasing the effective visual Contrast Ratio of the panel and producing a higher calibrated brightness than is achievable with traditional calibration methods. We can also make lower cost displays look almost as good as more expensive higher performance panels. These articles are a brief introductory critical analysis. Our optimizations correct these deficiencies and much more. If you are a display or product manufacturer and want to turn a standard panel into a spectacular one Contact DisplayMate Technologies to learn more.

Article Links: Google Nexus One OLED Display

Article Links: Apple iPhone 3GS LCD Display

Article Links: Motorola Droid LCD Display

Article Links: Display Technology Shoot-Out Article Series Overview and Home Page

Copyright © 1990-2010 by DisplayMate Technologies Corporation. All Rights Reserved.

This article, or any part thereof, may not be copied, reproduced, mirrored, distributed or incorporated

into any other work without the prior written permission of DisplayMate Technologies Corporation