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