Image Quality Matters in Smarthanheld --Tablet, Smartphone and Smartbook
Copyright © 2010 QuickLogic Corporation. All rights reserved.
Mobile Growth Drivers User base watching video on mobile phones grew 53%
User base watching video grew 13%, time spent watching video grew 4.6%
Tablet users consume 2.5X as many videos as the typical web user and three times as many videos as SmartPhone users
2012 CAGR
500
500 400
400
60%
300
300
40%
200
200
20%
100
100
0
0%
0
USB Modem
Smartphone Smartbook & Netbook & Cloudbook
Tablet
2012 Unit (millions)
80%
Sources: Forward Concepts, Gartner, ABI Research Copyright © 2010 QuickLogic Corporation. All rights reserved.
2
Trends Showing Mobile Video Consumption 55% of all Netflix users now streaming video Blockbuster Brings New Releases to Android and Windows Mobile-based Handsets China Multimedia Mobile Broadcasting to have more than 150M subscribers in 2013 AT&T streams content stored on home DVR to mobile devices YouTube accounts for 13% of mobile data bandwidth Video streaming is the fastest growing mobile application with a 92% increase in 2010
Copyright © 2010 QuickLogic Corporation. All rights reserved.
3
Sample iPad Reviews “The iPad offers a dynamic color display which supports video and animations and a touch-based interface but is limited by a relatively short battery life and screen readability issues, especially in natural light.” - PCWorld
“On that same vacation, I often read outside, which would have likely been impossible on the iPad. The iPad has a striking LCD display based on IPS technology (in-plane switching) which allows a broad viewing angle together with vibrant and accurate colors. IPS also requires a strong backlight, which means the display is unlikely to be readable in sunlight” - Sbooks Blog
“If you thought to take your iPad along for an outing in Central Park or at the beach, forget about it. While bright and contrasty indoors, the iPad's screen looks washed out and is almost impossible to view in bright sunlight” - iPad News Daily
Copyright © 2010 QuickLogic Corporation. All rights reserved.
4
VEE and DPO Address These Problems Through
Extended battery life, up to 25% and more
Better display viewability – in all lighting conditions, even under direct sunlight
A restoration of the viewing experience to a television-like level
Copyright © 2010 QuickLogic Corporation. All rights reserved.
5
The Ideal Video Viewing Environment Video is ideally viewed in controlled, calibrated environments Best use case is a dark room with a bright display, similar to a movie theatre Video performance is generally calibrated to these environments
Copyright © 2010 QuickLogic Corporation. All rights reserved.
6
The Reality of Viewing Video Video is viewed consumer mobile devices in many different environments, but normally without accommodation for all those situations Results in non-ideal video playback (screen too bright, not enough contrast, too dark, etc…)
QuickLogic’s VEE (Visual Enhancement Engine) technology dynamically compensates for different viewing environments and restores the viewing experience to a television-like experience, while DPO (Display Power Optimizer) technology works in concert to adjust display power or brightness to extended battery life
Copyright © 2010 QuickLogic Corporation. All rights reserved.
7
Visual Enhancement Engine (VEE) So what is VEE? “VEE enhances the users mobile visual experience while significantly extending battery life”
Benefits: Improves user experience for still & motion video content Extends battery life Copyright © 2010 QuickLogic Corporation. All rights reserved.
8
VEE and DPO Technology VEE adjusts video parameters such as dynamic range, contrast ratio, and color saturation on a pixel-by-pixel basis, while DPO adjusts backlight or display power, resulting in a much better restored viewing experience and greatly improved battery life
VEE On
VEE Off FAQ – ALS and VEE
Dynamic range, contrast ratio, and color saturation Copyright © 2010 QuickLogic Corporation. All rights reserved.
9
Maximizing the Effective Contrast Ratio 65,000:1
Details lost when contrast ratio reduced Mobile display, Lower backlight to save power, high ambient light
Contrast Ratio
10,000:1
VEE restores the details in the original content Dynamically calculates and applies a different tone curve to each pixel depending on content and position in the image Pixel-by-pixel dynamic range and colour correction enables far Effective better control of contrast than traditional techniques Contrast Ratio 400:1
130:1
110:1
600:1
100% backlight
30% backlight
Low ambient light
Samsung 46” LCD TV
30% backlight
Low ambient light
NEC 2.7” TFT LCD High ambient light Copyright © 2010 QuickLogic Corporation. All rights reserved.
10
VEE adapts to the available range
1,000:1
Content range
Original display’s dynamic range
Maps the signal to the full display range – no wasted capability
VEE content range
Perfectly matched to display X:1
Copyright © 2010 QuickLogic Corporation. All rights reserved.
11
VEE adapts to ambient light
Content range
Original display’s dynamic range
VEE is the only algorithm that adjusts the black level to match ambient light
Scaled content range
Complete content visible No content mapped here
Copyright © 2010 QuickLogic Corporation. All rights reserved.
12
VEE adapts backlight when needed In high ambient light situations, VEE increases backlight to maintain quality
Content range
Original display’s dynamic range
Increased backlight
Scaled content range
Copyright © 2010 QuickLogic Corporation. All rights reserved.
Complete content visible
13
System Implementation
VEE and DPO are available on QuickLogic’s Polar Pro and ArcticLink solution platforms Includes additional functions such as sharpening, black leveling, color correction and gamma correction FAQ – Availability of VEE and DPO Copyright © 2010 QuickLogic Corporation. All rights reserved.
14
7” Tablet Power Savings Data Use Case
Equivalent System Power Image Quality System Default Original VEE-Enabled Total Power Backlight Level Backlight Level System Power at Backlight Savings ( 80%) when Level ( 40%) VEE is disabled
Normal Office Light
Test Condition: Backlight level 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
40%
1.67W
1.76W
2.43W
System Battery Life Improvement
0.67W
27%
QCT 7227 + Android 2.1 + 7" 800x600 LCD Tablet System Power Consumption in Watt System Power(VEE Off) System Power(VEE On) 1.15 1.28 1.31 1.44 1.47 1.56 1.67 1.76 1.87 1.92 2.03 2.08 2.19 2.28 2.43 2.48 2.63 2.72 2.87 2.96
Copyright © 2010 QuickLogic Corporation. All rights reserved.
15
Real World Power Savings Form-factor OEM designs using DPO were measured to assess actual system-level power savings: Approximate Original Original System DPO-Enabled Power Backlight Level Ambient Light Backlight Level
DPO-Enabled System Power
Battery Life Improvement
15% 25% 45%
3.755W 3.945W 4.325W
13% 17% 16%
1.48W 1.6W 1.72W
13% 13% 26%
1.26W 1.26W 1.32W
14% 21% 23%
60% 80% 100%
1.24W 1.3W 1.39W
10% 10% 50%
1.12W 1.12W 1.28W
10% 14% 8%
10 lux 100 lux 10,000 lux
40% 60% 90%
1.52W 1.71W 2.42W
10% 20% 30%
1.08W 1.35W 1.42W
28% 21% 36%
10 lux 100 lux 10,000 lux
40% 60% 100%
4.43W 4.79W 5.7W
10% 20% 30%
4.12W 4.29W 4.46W
7% 10% 22%
Display Size
Product
Use Case
8.9"
Tablet
Airplane Indoor Outdoor
10 lux 100 lux 10,000 lux
45% 65% 85%
4.24W 4.63W 5.02W
Smartphone
Airplane Indoor Outdoor
10 lux 100 lux 10,000 lux
66% 80% 93%
Smartphone
Room Bright Room Outdoor
100 lux 600 lux 6500 lux
Tablet
Dark Room Indoor Outdoor
Tablet
Dark Room Indoor Outdoor
5"
4"
7"
10.1"
Data includes VEE/DPO power consumption Copyright © 2010 QuickLogic Corporation. All rights reserved.
16
Image Comparison 40% Backlight Strength when VEE is disabled
40% Backlight Strength when VEE is enabled Or 80% Backlight Strength when VEE is disabled
Copyright © 2010 QuickLogic Corporation. All rights reserved.
17
Gamma Correction Applied globally, bright detail can be lost
Copyright © 2010 QuickLogic Corporation. All rights reserved.
18
VEE Technology Details QuickLogic’s VEE technology is based on the iridix® algorithm from Apical Limited VEE algorithms implement a model of human perception, NOT machine perception
Resulting in a displayed image that retains detail, color and vitality under variable viewing conditions that is pleasing to the eye
VEE is a sophisticated method of dynamic range compression Applies different tonal and color transformations to every pixel in an image using a local tone mapping algorithm, NOT global
VEE specifically addresses the problem of low contrast ratio mobile displays to restore a television-like viewing experience to mobile devices VEE/DPO will provide superior image quality and power savings benefits on LCD (transmissive or transflective), OLED, and AMOLED displays Gamma Correction / ALC
iridix
Copyright © 2010 QuickLogic Corporation. All rights reserved.
19
Why Does QuickLogic Emphasize VEE’s Human Model of Perception?
How many shades of grey do you see?
Copyright © 2010 QuickLogic Corporation. All rights reserved.
20
Machine Measurements May Not Equal Human Perception
How many shades of red do you see?
Humans and Machines can ‘see’ very differently
Copyright © 2010 QuickLogic Corporation. All rights reserved.
21
VEE Example: Still Image
The unique feature is: a unique tone curve for every pixel of every video frame, calculated adaptively and automatically
Copyright © 2010 QuickLogic Corporation. All rights reserved.
22
sDRC Example: Motion Video
Strong correction of shadows while maintaining midtones and highlights
Copyright © 2010 QuickLogic Corporation. All rights reserved.
23
“ Must to Have” differentiation you need for tablet after i-PAD VEE/DPO provides the user a markedly better viewing experience in all lighting conditions and significantly extend system battery life Superior image quality become a key differentiation in the blooming tablet market after i-PAD It has been migrating from the “ Nice to have” onto “ Must to have” for winning in competition… Copyright © 2010 QuickLogic Corporation. All rights reserved.
24
VEE – “Seeing is Believing”
Copyright © 2010 QuickLogic Corporation. All rights reserved.
25
Calibrating VEE Enabled Displays
Copyright © 2010 QuickLogic Corporation. All rights reserved.
System Calibration
Backlight Strength (%)
VEE and DPO technology should calibrated to the specific OEM hardware system variables (display characteristics, performance requirements, usage models, etc… While some mobile OS platforms have an auto backlight vs. ambient light algorithm, QuickLogic recommends calibration for all possibilities if a user backlight control exists in the OEM system
100
0 0
10000 Ambient Light Level (lux)
The number of calibration conditions (represented by squares above) is at the
Android-based calibration softwarethe tools available for use discretion of the system designer—however, moreare conditions, the more in calibrating ‘golden’ samples end products effective VEE and DPO of technology can be VEE/DPO Calibration Tutorial Copyright © 2010 QuickLogic Corporation. All rights reserved.
27
Background VEE is a powerful Video Enhancement Engine that adapts video content to the limitations of mobile displays in different ambient and backlighting conditions The strength parameter of VEE controls how much it enhances the video stream – this tutorial shows how to determine the appropriate strength for various conditions
Copyright © 2010 QuickLogic Corporation. All rights reserved.
28
Test Pattern Since the ultimate arbiter of what looks “right” is the human visual system, we view test patterns to evaluate the display:
Copyright © 2010 QuickLogic Corporation. All rights reserved.
29
Detail on the Test Patterns The test patterns are organized as an array of squares The columns represent different background intensities – darkest on the left, brightest on the right The rows represent different foreground intensities – darkest at the top, brightest at the bottom Copyright © 2010 QuickLogic Corporation. All rights reserved.
30
Just Noticeable Difference The values where you can just notice the difference are called JNDs, or Just Noticeable Differences The JNDs vary with backlight and ambient light Vary the backlight on the previous slide to see this effect
Copyright © 2010 QuickLogic Corporation. All rights reserved.
31
How it works The basic idea is to put a square of one brightness on top of a square of a different brightness and ask the question: ‘Can you tell the difference?’ “No”
“Just”
Copyright © 2010 QuickLogic Corporation. All rights reserved.
“Yes”
32
Classic VEE Usage and First Steps The classic use for VEE is to preserve the ideal viewing experience even though the actual conditions are less than ideal So the first step is to evaluate the viewing experience under ideal conditions ( Strongest BL, Lowest AL)
Copyright © 2010 QuickLogic Corporation. All rights reserved.
33
Ideal Conditions for Calibration The ideal viewing conditions for a typical display are a dark room and full backlight We start by viewing the various test patterns under the ideal conditions and recording the JNDs Then we view the various test patterns under non-ideal conditions, and vary the strength parameter until we replicate the ideal JNDs
Copyright © 2010 QuickLogic Corporation. All rights reserved.
34
Simplified Example Z
0
1
2
Z
Z
Z
Z
0
0
0
0
1
1
1
1
2
2
2
2
Ideal JND: Ambient: 10 lux Backlight: 100% Strength: 0 Z
0
1
2
N
N
Y
Y
N
N
Y
Y
Y
Y
N
Y
Y
Y
Y
N
Note: Intensities artificially exaggerated to make this display independent Copyright © 2010 QuickLogic Corporation. All rights reserved.
35
Non-Ideal Conditions Z
0
1
2
Z
Z
Z
Z
0
0
0
0
1
1
1
1
2
2
2
2
Non-Ideal JND: Ambient: 10 lux Backlight: 30% Strength: 0 Z
0
1
2
N
N
N
Y
N
N
N
Y
N
N
N
Y
Y
Y
Y
N
Note: Intensities artificially exaggerated to make this display independent Copyright © 2010 QuickLogic Corporation. All rights reserved.
36
Compensated JND Z
0
1
2
Z
Z
Z
Z
0
0
0
0
1
1
1
1
2
2
2
2
Compensated JND: Ambient: 10 lux Backlight: 30% Strength: 30 Z
0
1
2
N
N
Y
Y
N
N
Y
Y
Y
Y
N
Y
Y
Y
Y
N
Note: Intensities artificially exaggerated to make this display independent Copyright © 2010 QuickLogic Corporation. All rights reserved.
37
Compensated JND Results In this case you can see that the JND for the lowered backlight closely matches the JND for the Ideal Conditions This is the appropriate strength for these conditions
We then repeat this process for other conditions and test patterns
Copyright © 2010 QuickLogic Corporation. All rights reserved.
38
Over Compensated Z
0
1
2
Z
Z
Z
Z
0
0
0
0
1
2
1
2
1
2
Non-Ideal JND: Ambient: 10 lx Backlight: 100% Strength: 100 These conditions become visible
1
2
Z
0
1
2
N
Y
Y
Y
Y
N
Y
Y
Y
Y
N
Y
Y
Y
Y
N
Note: Intensities artificially exaggerated to make this display independent Copyright © 2010 QuickLogic Corporation. All rights reserved.
39
Over Compensation In this case we’ve made the strength stronger than was necessary to achieve parity with the Ideal Conditions We are enhancing the image If we do this too much, then the image starts to look different – Night starts to look like day Image artifacts, such as blocking become intrusive
Copyright © 2010 QuickLogic Corporation. All rights reserved.
40
Over Compensation Instead of artificially overcompensating, we recommend choosing a different reference For example, display the same source material on a higher quality screen and use that to define the ‘Ideal Conditions’ JND tables
Copyright © 2010 QuickLogic Corporation. All rights reserved.
41
