Apple patent involves color correction of electronic displays
TweetFollow Us on Twitter

Apple patent involves color correction of electronic displays

Apple is eyeing ways to beef up the color correction on its electronic displays. A patent (number 20110032275) for color correction of electronic displays utilizing gain controls has appeared at the US Patent & Trademark Office. It generally relates to display correction and, more specifically, to correcting the displayed color by reducing its dependency on various variables, such as temperature.

A video-rendering chip performs gain correction on received display input, based on a display temperature, to produce output values that are shown on the display. The video-rendering chip includes multipliers, a microprocessor, and a memory. The microprocessor receives a display temperature from a sensor, determines gain correction coefficients that correspond to the display temperature, and provides the correction coefficients to the multipliers. The multipliers then multiply the display input by the correction coefficients to produce the output values. The microprocessor may determine the correction coefficients utilizing a lookup table or a correction coefficient formula stored in the memory.

The microprocessor may receive an updated display temperature periodically and may determine new correction coefficients that correspond to the updated display temperature. The microprocessor may receive updated display temperatures at fixed periods or at varying periods based on the previous display temperature. The inventors Gabriel G. Marcu, David Lum and Wei Chen.

Here's Apple's background and summary of the invention: "Many computing devices use an electronic display to present information to a user. Such displays may be, for example, liquid crystal displays ('LCDs'), cathode ray tubes ('CRTs'), organic light emitting diode displays ("OLED displays") and so on. Most such displays can show color images. However, the color response of a display may change as the display operates.

"In particular, the display's white point may shift along a blackbody curve as the physical temperature of the display reaches a steady operating temperature. For example, when a display is turned on, the display may be cold and the temperature of the display may increase as the display warms up over time. The changing temperature of the display may cause the display colors to shift. For example, some displays depict white as somewhat yellowish when initially powered on and cold.

"As the display warms, the white point of the display shifts toward a more neutral white, such as defined by the standard illuminant, D65. The same is true for any colors shown on the display; they too shift within a color space as the temperature of the display increases. This is true even if, for example, the display only outputs grayscale colors (e.g., is a black and white display). Similarly, other parameters of the display may shift as a function of temperature such as luminance, black level, contrast, or electro-optical transfer function, which may be referred to as the "native gamma" of the display. This set of parameters may be referred to as the color profile of the display.

"The shift in the color profile due to temperature increase of the display generally causes each pixel of the display to change color until a stable operating temperature is achieved, at which point the pixel colors are likewise stable. That is, although a pixel may be instructed to display the same color at an initial temperature and a stable operating temperature, the actual color displayed, as objectively measured by its chrominance and luminance, may vary.

"It should be noted that, in many electronic systems, individual pixels of a display receive a red, green and blue value that together define the color to be created by the pixel. These red, green and blue values are referred to herein in the aggregate as an 'RGB value,' as understood to those of ordinary skill in the art.

"Thus, a method of adjusting the display colors over a range of display temperatures is desirable. Accordingly, there is a need in the art for an improved method of providing consistent display colors over a range of parameters including temperature.

"In an embodiment, a display device receives video input and utilizes a video-rendering chip to perform gain correction on the video input, based on a display temperature, to produce output values. The output values are provided to a display driver which controls the hardware of the display to show the output values on the display.

"The video-rendering chip includes a videorendering engine, a microprocessor, and a memory. The microprocessor receives a sampled display temperature from a temperature sensor, determines correction coefficients that correspond to the sampled display temperature, and provides the correction coefficients to the video-rendering engine. The video-rendering engine then utilizes multipliers to multiply the display input by the correction coefficients to produce the output values. The video-rendering engine may utilize a dithering component to dither the output values before providing the output values to the display driver.

"In some embodiments, the microprocessor may determine the correction coefficients by retrieving the correction coefficients that correspond to the sampled display temperature from a lookup table stored in the memory. The lookup table stored in the memory may include correction coefficients that correspond to the sampled display temperature. Alternatively, the correction coefficients may be interpolated from correction coefficients that correspond to other display temperatures included in the lookup table. In other embodiments, the microprocessor may determine the correction coefficients by retrieving a correction coefficient formula stored in the memory and applying the correction coefficient formula to the sampled display temperature to produce the correction coefficients.

"The microprocessor may receive a sampled display temperature periodically. After the microprocessor receives the display temperature at a first time and determines correction coefficients that corresponded to the sampled display temperature at the first time, the video-rendering engine may apply the correction coefficients that corresponded to the sampled display temperature at the first time to received display input until the microprocessor received a sampled display temperature at a second time. After the microprocessor received the display temperature sampled at the second time, the microprocessor determines correction coefficients that correspond to the display temperature sampled at the second time and the video-rendering engine applies the correction coefficients that correspond to the display temperature sampled at the second time to the display input received after the second time.

"In some embodiments, the video-rendering chip may sample the display temperature at fixed periods, such as every second. In other embodiments, the video-rendering chip may vary the periods at which the microprocessor receives the sampled display temperature based on the previously sampled display temperature."

-- Dennis Sellers
dsellers@applecentral.com

 
AAPL
$519.01
Apple Inc.
+0.00
MSFT
$40.40
Microsoft Corpora
+0.00
GOOG
$556.54
Google Inc.
+0.00

MacTech Search:
Community Search:

Software Updates via MacUpdate

PDFpenPro 6.2 - Advanced PDF toolkit for...
PDFpenPro allows users to edit PDF's easily. Add text, images and signatures. Fill out PDF forms. Merge or split PDF documents. Reorder and delete pages. Even correct text and edit graphics! Create... Read more
PDFpen 6.2 - Edit and annotate PDFs with...
PDFpen allows users to easily edit PDF's. Add text, images and signatures. Fill out PDF forms. Merge or split PDF documents. Reorder and delete pages. Even correct text and edit graphics! Features... Read more
Monolingual 1.5.9 - Remove unwanted OS X...
Monolingual is a program for removing unnecesary language resources from OS X, in order to reclaim several hundred megabytes of disk space. It requires a 64-bit capable Intel-based Mac and at least... Read more
Maya 2015 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
Starcraft II: Wings of Liberty 1.1.1.180...
Download the patch by launching the Starcraft II game and downloading it through the Battle.net connection within the app. Starcraft II: Wings of Liberty is a strategy game played in real-time. You... Read more
Sibelius 7.5.0 - Music notation solution...
Sibelius is the world's best-selling music notation software for Mac. It is as intuitive to use as a pen, yet so powerful that it does most things in less than the blink of an eye. The demo includes... Read more
Typinator 5.9 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
MYStuff Pro 2.0.16 - Create inventories...
MYStuff Pro is the most flexible way to create detail-rich inventories for your home or small business. Add items to MYStuff by dragging and dropping existing information, uploading new images, or... Read more
TurboTax 2013.r17.002 - Manage your 2013...
TurboTax guides you through your tax return step by step, does all the calculations, and checks your return for errors and overlooked deductions. It lets you file your return electronically to get... Read more
TrailRunner 3.8.769 - Route planning for...
Note: While the software is classified as freeware, it is actually donationware. Please consider making a donation to help support development. TrailRunner is the perfect companion for runners,... Read more

Latest Forum Discussions

See All

Download pickWEB and Access a Thematic C...
Download pickWEB and Access a Thematic Catalogue of the World’s Most Interesting Websites [Sponsored] Posted by Simon Reed on April 17th, 2014 [ | Read more »
Unpossible (Games)
Unpossible 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: **Important** Requires at least iPad 2, iPhone 4S, iPod Touch (5th gen), or newer. | Read more »
Hitman GO (Games)
Hitman GO 1.2 Device: iOS Universal Category: Games Price: $4.99, Version: 1.2 (iTunes) Description: Get your daily fix of Agent 47 with this elegant, strategy-based Hitman game! | Read more »
The Seventh Sign: Hodappy Bird Released...
The Seventh Sign: Hodappy Bird Released on the App Store Posted by Jeff Scott on April 16th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Rogue Heroes (Games)
Rogue Heroes 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Rogue Heroes is awesome fast-paced 2D action-platforming roguelike game with RPG elements. - explore the depth of procedurally... | Read more »
Fourcast Review
Fourcast Review By Jennifer Allen on April 16th, 2014 Our Rating: :: VIDEO POTENTIALiPhone App - Designed for the iPhone, compatible with the iPad Fourcast is a great idea for combining video clips, but it does lack a number of... | Read more »
Hearthstone: Heroes of Warcraft is Avail...
Hearthstone: Heroes of Warcraft is Available on the U.S. App Store Right Now – Gogogogo! Posted by Rob Rich on April 16th, 2014 [ permalink ] | Read more »
Grammar Pop HD Review
Grammar Pop HD Review By Jennifer Allen on April 16th, 2014 Our Rating: :: FUN LEARNINGiPad Only App - Designed for the iPad Learning the different parts of speech isn’t always fun, but Grammar Pop HD makes it much more... | Read more »
Groundskeeper2 Review
Groundskeeper2 Review By Nadia Oxford on April 16th, 2014 Our Rating: :: SLICE THOSE ALIEN SLIMEUniversal App - Designed for iPhone and iPad Putting aside some minor control issues, Groundskeeper2 is a fun and furious action/... | Read more »
Pinnacle Studio for iPhone (Photography...
Pinnacle Studio for iPhone 5.0 Device: iOS iPhone Category: Photography Price: $9.99, Version: 5.0 (iTunes) Description: | Read more »

Price Scanner via MacPrices.net

Apple now offering refurbished iPad mini with...
The Apple Store has Certified Refurbished 2nd generation iPad minis with Retina Displays now available starting at $339. Apple’s one-year warranty is included with each model, and shipping is free.... Read more
Microsoft Blinks – Drops Microsoft Office 365...
Microsoft has dropped the annual subscription fee for Microsoft Office 365 Personal – which is needed in order to create and edit documents in Microsoft Office for iPad. However, Apple’s iOS and OS X... Read more
New AVG Vault Apps for iOS and Android Help K...
AVG Technologies N.V. an online security company for 177 million active users, has announced the launch of its latest mobile application, AVG Vault. The free app introduces an innovative user... Read more
Free Local Carrot iPhone App Helps Find Fresh...
I love fresh vegetables. I’m not a vegan, although I was for several years in the 1980s, but fresh vegetables and other whole foods are still my dietary mainstays as a matter of taste rather than... Read more
CarSO Pro – Car Service and Finance Manager/O...
Lviv, Ukraine-based BM-Studios’ CarSO Pro is a tool to manage operations concerning your car. Never forget to change the oil or prolong the insurance for your car. Remember when you’ve done the car... Read more
Apple refurbished iPad Airs available startin...
Apple is now offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. The following Airs are available today: -... Read more
21-inch 2.7GHz iMac on sale for $1179, save $...
B&H Photo has the 21″ 2.7GHz iMac on sale for $1179 including free shipping plus NY sales tax only. Their price is $120 off MSRP. Add an iMac to your shopping cart, and B&H will offer an... Read more
Download our app, iTracx, for iOS and Android
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more
Education discounts shave up to $300 off the...
Purchase a new Mac at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and all... Read more
Save $50 on Mac mini Server
B&H Photo has the 2012 Mac mini Server on sale for $949 including free shipping plus NY sales tax only. Their price is $50 off MSRP. Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Retail - Manager - Holyoke - Apple I...
Job Summary Keeping an Apple Store thriving requires a diverse set of leadership skills, and as a Manager, you’re a master of them all. In the store’s fast-paced, Read more
*Apple* Retail - Manager - Apple (United Sta...
Job SummaryKeeping an Apple Store thriving requires a diverse set of leadership skills, and as a Manager, you're a master of them all. In the store's fast-paced, dynamic Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Retail - Market Leader - Cincinnati...
…challenges of developing individuals, building teams, and affecting growth across Apple Stores. You demonstrate successful leadership ability - focusing on excellence Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.