Motorola Droid LCD 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 IV 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 is an in-depth scientific analysis of the display on the Motorola Droid.   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 the Motorola Droid and Nexus One 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.   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.

 

Important Note for the 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 processes 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 below 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… 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.

 

FIGURE 1

Figure 1.  Revealing Screen Shots for the Google Nexus One and Motorola Droid.

Figure 1.  Revealing Screen Shots for the Google Nexus One and Motorola Droid.

The test patterns are 24-bit bmp at the native resolution of each display.

 

Test and Evaluate Your Own Displays Online

Our display evaluations involve hundreds of proprietary DisplayMate test patterns, test photos and instrument measurements. But using the same NASA Sunset on Mars photo that we used above in Figure 1 you can perform a good basic test and evaluation of your own smartphone, mobile display, computer monitor, or HDTV display for 24-bit color, false contouring, color fringing, image scaling, artifacts and noise. On a high quality artifact free 24-bit color display the image brightness will change very smoothly in all directions from the Sun. You shouldn’t see any intensity stepping, color fringing, noise or other irregularities. Test and evaluate the display with both the Browser and a Photo Viewer – the results frequently differ. Most computer monitors and HDTVs will perform well, but most smartphones and mobile displays will not…

 

Display Test with a Browser

View both the High Definition 1080 Resolution and the lower Standard Definition 480 Resolution photos using the two links below. Both photos should look the same, but may or may not appear the same size on your screen depending on the scaling settings and native resolution of your display. If the two images appear different (other than size) then there is a problem with image scaling, which processes images so they fit the native resolution of the display. On most computer monitors and HDTVs there will be little or no scaling needed and the Standard Definition image will fill only part of the screen. Compare the results with Figure 1.

 

High Definition 1080 Resolution Link:  NASA Photo - Sunset on Mars

Standard Definition 480 Resolution Link:  NASA Photo - Sunset on Mars

 

Display Test with a Photo Viewer

The above two links test the display and Browser together. To test the display with a Photo Viewer on your smartphone, mobile display, computer monitor or HDTV, download and save each photo (by pressing and holding your finger on most touchscreen smartphones or right clicking on most computer browsers). Move the files into one of the Photo Viewer folders if they weren’t automatically downloaded there. Launch the Photo Viewer (Gallery on Android phones) and compare the results obtained with the Browser and Figure 1.

 

 

Results and Conclusions

To make things as easy as possible, we are starting off with a summary of the test results and conclusions.

For detailed explanations and interpretations see the Measurements and Test Pattern Tests sections that follow below.

 

The display was evaluated by downloading 24-bit native resolution 854x480 test patterns and 24-bit HD resolution test photos to the phone. Note that we are testing and evaluating the display on the Droid with whatever hardware, firmware, OS and software are provided by Motorola.

 

Color Depth and Granularity:  Excellent Artifact Free 24-bit Color

The Droid provides full on-screen 24-bit color, which has 256 possible intensity levels for each of the Red, Green and Blue sub-pixels that are used to mix and produce all of the on-screen image colors. It’s the same as what is found on most monitors and HDTVs. When done properly, as on the Droid, it produces a nice color and intensity scale with few visible artifacts. Figure 1 shows the smooth intensity scale for both a photograph and test pattern that are visibly free of artifacts on the Droid.

 

Display Image Quality, Colors and Artifacts:  Excellent

The image and picture quality on the Droid is excellent across the board, including text, icons, and menu graphics. In the important category of images, pictures and photographs from external sources, whether they be from digital cameras or web content, are rendered quite well. The calibration is very good and the images and photos are rendered relatively artifact free, including the critical rescaling function that is needed to fit images and photos onto the native 854x480 resolution of the display. The image and picture quality on the Droid is actually better than in most computer monitors and HDTVs. However, there is a problem with rescaling in the Android Browser on the Droid, which exhibits the same artifacts as the Nexus One, and will presumably be fixed in the future.

 

Measurements and Test Pattern Tests Summary:

The following is a brief summary of the main results of the Measurements and Test Pattern Tests sections, which follow immediately below with lots of additional background information and explanations.

 

1.       The Maximum Brightness or Peak Luminance of 449 cd/m² is excellent and about as bright as you’ll find on any current mobile display. It’s fine for just about everything except near direct sunlight.

 

2.       The (true) Contrast Ratio is 1,436, which is comparable to the best LCDs. Don’t confuse the true Contrast Ratio with the tremendously inflated values that are published by many manufacturers. The Dynamic Contrast Ratio for the Droid is 2,721.

 

3.       The Screen Reflectance, which is the most important specification for a mobile display used in high ambient lighting, is 12.1 percent, which is in the middle of the range of values we’ve measured for mobile devices. Together with the high Peak Brightness this makes the Droid a very good performer in bright situations.

 

4.       The High Ambient Light Contrast Rating of 37 is very good, so the Droid is among the best mobile displays for high ambient lighting. For all mobile devices the High Ambient Light Contrast Rating is much more important than the Contrast Ratio, which only applies to low ambient light environments.

 

5.       The Color Gamut of the Droid is an excellent match to the industry standard Color Gamut, which is necessary for accurate color reproduction for most content. For the data see Figure 2 in the Measurements section below.

 

The Measurements section below also analyzes the display’s Intensity Scale and Gamma, the variation of Brightness, Contrast Ratio and Color Shift with Viewing Angle, the Power Consumption and Light Spectrum of the display.

 

The Viewing Tests:  Excellent

We compared the Motorola Droid side-by-side to a calibrated Professional Sony High Definition Studio Monitor using a large set of DisplayMate Calibration and Test Photographs. All of the photos on the Droid were an excellent match, including faces and well known objects such as fruits, vegetables, flowers, grass, even a Coca-Cola can. The image and picture quality on the Droid is actually better than in most computer monitors and HDTVs. This is the result of an excellent factory calibration of the Color Gamut and Intensity Scales.

 

Factory Calibration and Quality Control:  Very Good

The overall factory calibration and quality control for the Motorola Droid display are very good. The accuracy of the white point and color and gray-scale tracking are all very good, which means that the Red, Green and Blue primaries have been carefully calibrated and balanced. The images are relatively free of objectionable artifacts.

 

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 below. Also ask Google to fix the poor image rescaling and its 16-bit implementation in the Browser and possibly other Android OS applications.

 

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.

 

 

What’s Coming Next: The Nexus One, iPhone and The Shoot-Outs…

In Part I we similarly test and analyze the Google Nexus One. Part II is devoted to the Apple iPhone 3GS. Part III is a detailed point-for-point Shoot-Out comparison between the displays on the Nexus One and the iPhone 3GS. Part V is a detailed point-for-point Shoot-Out comparison between the displays on the Nexus One and the Motorola Droid.

 

 

The Measurements with Explanations and Interpretations

This section explains all of the measurements incorporated in the article. The display was evaluated by downloading 24-bit native resolution 854x480 test patterns and 24-bit HD resolution test photos to the Motorola Droid. Note that we are testing and evaluating the display on the Droid with whatever hardware, firmware, OS and software are provided by Motorola. All measurements were made using DisplayMate Multimedia Edition for Mobile Displays to generate the analytical test patterns together with a Konica Minolta CS-200 ChromaMeter, which is a Spectroradiometer. All measurements were made in a perfectly dark lab to avoid light contamination. All devices were tested with their Backlight set for maximum brightness with the Automatic Brightness light sensor control turned off, and running on their AC power adapter with a fully charged battery, so that the battery performance and state was not a factor in the results. For further in-depth discussions and explanations of the tests, measurements, and their interpretation refer to earlier articles in the DisplayMate Multimedia Display Technology Shoot-Out article series and the DisplayMate Mobile Display Shoot-Out article series.

 

Konica Minolta CS-200

 

1.  Peak Brightness:  449 cd/m²  –  Excellent brightness for a Mobile Display

This is the maximum brightness that the display can produce, called the Peak White Luminance. 449 cd/m² is about as bright as you’ll find on any current mobile display. It’s fine for just about everything except direct sunlight, although it may be too bright for comfortable viewing under dim ambient lighting. If you find that to be the case, turn on the Droid’s Automatic Brightness, which uses a light sensor to adjust the Peak Brightness settings. Since that can be used to decrease the power used by the backlight it will also increase the battery run time.

 

2.  Black Level Brightness:  0.165 cd/m²  –  Good for a Mobile Display

The Black Level is the closest approximation to true black that the display can produce. Almost all displays wind up producing a visible dark gray on-screen instead of true black. This is a major problem for LCDs. The glow reduces image contrast and screen readability and can be distracting or even annoying in dark environments. It ruins the dark end of the display’s intensity/gray scale and washes out colors in the image. But note that in bright ambient lighting the Black Level is irrelevant because reflections off the screen dominate the screen background brightness. The Droid’s value of 0.165 cd/m² is very dark for a mobile display in typical ambient lighting. Note that if you decrease the screen Brightness with the (Backlight) Brightness Control, the Black Brightness will also decrease proportionally by the same amount, so in dimmer ambient lighting the Black Brightness can be reduced significantly if desired.

 

3.  Contrast Ratio  –  Only Relevant for Low Ambient Light:  1,436  –  Good for Mobile  –  Dynamic Contrast is 2,721

The Contrast Ratio is a measure of the full range of brightness that the display is capable of producing. It is the ratio of Peak Brightness to Black Level Brightness. The larger the Contrast Ratio the better, but it is only relevant for low ambient lighting because reflections off the screen dominate the display’s Black Level in bright ambient lighting. The very best LCDs now have (true) Contrast Ratios of 1,500 to 2,000 so the 1,436 value for the Droid is very impressive in a mobile device. Don’t confuse the true Contrast Ratio with the tremendously inflated values that are published by many manufacturers. Because the Droid uses Dynamic Contrast (see below) the Contrast Ratio from the brightness values in 1 and 2 above is a Dynamic Contrast Ratio, and it’s 2,721. The static or true Contrast Ratio for the Droid is 1,436, which is measured at low APL where the Dynamic Contrast has a constant value (see below).

 

4.  Screen Reflectance of Ambient Light:  12.1 Percent  –  Average

The often overlooked Screen Reflectance is actually the most important parameter for a mobile display, even more important than Peak Brightness. The screen reflects a certain percentage of the surrounding ambient light, which adds to the screen background, washes out the image, and makes it harder to see what is on the screen. In high ambient lighting the Screen Reflectance can significantly reduce the visibility and readability of screen content. The lower the Screen Reflectance the better. The value for the Droid of 12.1 percent is in the middle of the range of values we’ve measured for mobile devices. Lowering the Screen Reflectance increases the cost of a display, but it’s the easiest and best way to improve screen readability under bright ambient light. The Screen Reflectance measurements were done in accordance with VESA FPDM 308-1, Reflectance with Diffuse Illumination, using an integrating hemispherical dome and a calibrated diffuse white reflectance standard.

 

5.  High Ambient Light Contrast Rating:  37  –  Very Good

In the same way that the Contrast Ratio measures the screen contrast under low ambient lighting, the Contrast Rating specifies the relative screen contrast under high ambient lighting. It is the ratio of Peak Brightness to Screen Reflectance. The higher the value the better you’ll be able to see what’s on the screen when you are in a bright location. 37 is relatively high, so the Droid is among the best mobile displays for high ambient lighting. For all mobile devices the High Ambient Light Contrast Rating is much more important than the Contrast Ratio.

 

6.  Dynamic Color and Dynamic Contrast:  Yes  –  But for Reducing Power Consumption

Some displays dynamically adjust the color, gray scale and contrast on every image that is displayed using an internal automatic image processing algorithm. The goal is generally to jazz up and “enhance” the picture by stretching and exaggerating the colors and intensity scale. It is similar to the Vivid mode found in many digital cameras and HDTVs. Since it alters and frequently distorts the image it is better left as an option for people who aren’t concerned with picture accuracy and fidelity. Since the Dynamic modes are generally triggered by changes in Average Picture Level, a very simple test for Dynamic Contrast is to separately measure the brightness of full screen Red, Green and Blue images and then compare them to White, which should equal their sum. If they don’t agree then there is Dynamic Color and Contrast processing. For the Droid, the measured Luminance for Red=53, Green=275 and Blue=19 cd/m². Their sum is 347 cd/m², which is 23 percent lower than the measured value for White, 449 cd/m², so the Droid uses a moderate amount of Dynamic Color and Contrast. In fact, at low APL the peak luminance decreases to 237 cd/m² as a result of dimming the LCD backlight, suggesting that the actual goal is to reduce power consumption, rather than image “enhancement.” Still we recommend that Dynamic processing be an option that the user can turn on and off.

 

7.  Color Temperature and Chromaticity:  6752 degrees Kelvin  –  Very Close to D6500, Excellent

White is not a single color but rather falls within a range that is normally specified by a Color Temperature. For accurate color reproduction of most content, including photographs, images and web content it needs to be the industry standard D6500, which is how most professional photo and video content is color balanced. D6500 is the color of natural daylight and is similar to a Black Body at 6500 degrees Kelvin. The Droid’s White Point is actually very close to D6500 – see the White Points in Figure 2 below. The measured CIE Chromaticity Coordinates of the White Point are u’=0.1946 v’=0.4680.

 

8.  Color Gamut:  Excellent Match to the sRGB / Rec.709 Standard

The Color Gamut of a display is the range and set of colors that it can produce. The only way that a display will deliver good color and gray scale accuracy is if it is accurately calibrated to an industry standard specification, which for computers, digital cameras, and HDTVs is sRGB or Rec.709. It’s the standard for most content and necessary for accurate color reproduction. If the Color Gamut is smaller than the standard then the image colors will appear too weak and under-saturated. If the Color Gamut is greater than the standard then the image colors will appear too strong and over-saturated. The important point here is that a Color Gamut larger than the standard is also bad, not better. Wider gamuts will not show you any colors or content that are not in the original images, which are almost always color balanced for the sRGB / Rec.709 standard. Wider color gamuts simply distort and decrease color accuracy and should be avoided, except for some special applications.

 

Figure 2 shows the measured Color Gamut for the Nexus One and the Motorola Droid alongside the Standard sRGB / Rec.709 Color Gamut in a CIE 1976 Uniform Chromaticity Diagram. The dots in the center are the measured White Points for the phones along with the D6500 Standard, which is marked as a white circle. The outermost curve are the pure spectral colors and the diagonal line on the bottom right is the line of purples. A given display can only reproduce the colors that lie inside of the triangle formed by its primary colors. Highly saturated colors seldom occur in nature so the colors that are outside of the standard sRGB / Rec.709 triangle are seldom needed and are unlikely to be noticed or missed in the overwhelming majority of real images. When a camera or display can’t reproduce a given color it simply produces the closest most saturated color that it can.

 

FIGURE 2

Figure 2.  CIE 1976 Uniform Chromaticity Diagram showing the Color Gamut and White Points for the Nexus One and Motorola Droid

 

The Droid produces an excellent match to the standard Color Gamut, which is the black triangle in Figure 2, while the Nexus One has much too large a color Gamut. As a result the Droid produces images with an excellent color balance while the Nexus One produces images that have significantly too much color saturation. This applies to all external content viewed on the displays, including web content, such as images, photos and videos. This was easy to see in the viewing tests where we compared the displays side-by-side to a calibrated Professional Sony High Definition Studio Monitor using a large set of DisplayMate Calibration and Test Photographs. All of the photos on the Droid were an excellent match, including faces and well known objects such as fruits, vegetables, flowers, grass, even a Coca-Cola can, while the Nexus One photos had way too much color, to the point of appearing gaudy.

 

9.  Intensity Scale, Image Contrast and Gamma:  Very Good Match to the Standard

The display’s intensity scale not only controls the contrast within an image but it also controls how the Red, Green and Blue primary colors mix to produce all of the on-screen colors. So if it doesn’t obey the industry standard intensity scale then the colors and intensities will be wrong everywhere on-screen because virtually all professional content and all digital cameras use the sRGB / Rec.709 standard, so it’s necessary for accurate image, picture and color reproduction. The standard intensity scale is not linear but rather follows a mathematical power-law, so it is a straight line on a log-log graph. Its slope is called Gamma, which is 2.2 in the standards. In order to deliver accurate color and intensity scales a display must closely match the standard. Figure 3 shows the measured (Transfer Function) Intensity Scale for the Motorola Droid and Nexus One alongside the industry standard Gamma of 2.2, which is a straight line.

 

FIGURE 3

Figure 3.  Intensity Scale for the Nexus One and Motorola Droid

 

The Droid provides a very good match with respect to the standard intensity scale, which is needed in order to accurately reproduce images and pictures for most content. It’s actually better than most HDTVs and computer monitors. Gamma is the slope of the intensity scale, which should be a constant 2.2 like the straight line in Figure 3. In the central 20 to 80 percent signal range the Gamma for the Droid is 2.24, which is an excellent match to the standard.

 

10.  Brightness Decrease with Viewing Angle:  64 percent Decrease in 30 degrees  –  Bad, Very Large

A major problem with many displays, especially LCDs, is that the image changes with the viewing angle, sometimes dramatically. The Peak Brightness, Black Luminance, Contrast Ratio and color generally change with viewing angle (see below). Some display technologies are much better than others. At a moderate 30 degree viewing angle the Peak Brightness of the Droid fell by 64 percent to 160 cd/m², which is an incredibly large decrease. This behavior is typical for LCDs.

 

11.  Black Level and Contrast Ratio Shift with Viewing Angle:  Bad, Very Large

At a moderate 30 degree viewing angle the Black Level Brightness increased by 88 percent to 0.31 cd/m²,  the Contrast Ratio fell to 280 and the Dynamic Contrast to 516. This behavior is typical for LCDs.

 

12.  Color Shift with Viewing Angle:  Excellent, no Visible Shift

Colors generally shift with viewing angle whenever the brightness shifts with viewing angle because the Red, Green and Blue sub-pixels each shift independently and vary with intensity level. At a moderate 30 degree viewing angle Red shifted the most, by Δ(u’v’) = 0.0020, which is ½ times the Just Noticeable Color Difference. Green also by Δ(u’v’) = 0.0020 and Blue shifted the least by 0.0016. These values are so low that the Motorola Droid shows no visible color shift with angle.

 

13.  RGB Display Power Consumption:  Good, Relatively Low

The power consumed by LCD displays is independent of the brightness and color distribution of the images – it only depends on the Brightness setting of the backlight that illuminates the LCD from behind. Dynamic Contrast and the Ambient Light Sensor both modify the manual user backlight brightness setting. The Automatic Brightness option allows the ambient light sensor on the Motorola Droid to adjust the backlight brightness and power setting as the ambient light changes. This not only improves visual comfort but can also increase the battery run time. We turned off Automatic Brightness for the tests but Dynamic Contrast is fully automatic and cannot be disabled so the power varies with the Average Picture Level, falling to a low as 53 percent of Maximum for the lowest APLs. It is possible to indirectly determine the power used by the display by measuring the AC power used by the Droid with different backlight settings. The average power used when the display is dark in standby mode is used as the baseline and is subtracted from the power measured for the other states.

 

Table 1 lists the Measured Relative Power, the Measured Luminance, and the Relative Luminous Efficiency, which is just the Measured Luminance divided by the Measured Relative Power, and normalized to 1.0 for White, which has the highest total efficiency.

 

Table 1.  Motorola Droid LCD Display Power Consumption

 

 

14.  OLED and LCD Spectra:  Very Interesting

The spectra of an LCD display is just the spectrum of the backlight filtered through the individual Red, Green and Blue sub-pixel filters within the panel. OLEDs are emissive devices so the spectra of the Nexus One is just the sum of the individual Red, Green and Blue OLED spectra, modified slightly by the touchscreen layer and anti-reflection absorption layer through which their light must pass. We thought it would be very useful and interesting to compare the spectra of the Nexus One with the spectra of the Motorola Droid, so we asked Konica Minolta to loan us their flagship CS-2000 Spectroradiometer to perform the measurements. The spectra for White, which is the sum of the Red, Green and Blue primaries is shown in Figure 4 for both the Nexus One and Motorola Droid.

 

FIGURE 4

Figure 4.  RGB Spectra for the Nexus One and Motorola Droid

 

As expected the OLED RGB spectra are relatively narrow because of their high color saturation. The Motorola Droid LCD RGB spectra is a filtered broadband spectrum. The backlight for the Droid is a white LED, which consists of a Blue LED with a yellow phosphor.

 

 

Special Thanks to Jay Catral of Konica Minolta for visiting our 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.

 

 

DisplayMate Test Pattern Tests and Comments

The DisplayMate Multimedia Editions that we used to analyze the displays on the Nexus One, iPhone 3GS and Motorola Droid have hundreds of test patterns to search for all sorts of both major and subtle display performance issues and artifacts.

 

The display on the Motorola Droid behaved as expected for a typical LCD. It was very well calibrated and performed very well on the analytical test patterns. The most interesting and relevant test patterns for the Droid analysis were the native 854x480 resolution test patterns generated by the DisplayMate Multimedia Edition for Mobile Displays. Below are additional comments on a number of particular tests and test patterns:

 

1. 256 Intensity Level RGBW Color Ramps – checks for 24-bit color and intensity scale irregularities and artifacts.

 

2. Screen Uniformity test patterns demonstrate screen mottling and irregularities, especially noticeable at low intensities.

 

3. Moiré Montage and many other test patterns demonstrate rescaling or compression artifacts at the display’s native resolution.

 

4. The set of Test and Calibration Photos in the DisplayMate Multimedia Edition for Mobile Displays and the DisplayMate Multimedia with Test Photos Edition were used to compare the Nexus One, iPhone 3GS and Motorola Droid to a calibrated Professional Sony High Definition Studio Monitor in order to evaluate picture quality and accuracy.

 

 

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@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:  Nexus One versus iPhone 3GS Display Comparison Shoot-Out

Article Links:  Nexus One versus Motorola Droid Display Comparison Shoot-Out

 

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

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

 

 

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