Apple working on radially-based chroma noise reduction for cameras
TweetFollow Us on Twitter

Apple working on radially-based chroma noise reduction for cameras

Apple is working on ways to further improve photo taking on its iOS devices, per a patent (number 8274583) at the U.S. Patent & Trademark Office. It's for radially-based chroma noise reduction for cameras.

Per the patent, a system, apparatus, computer readable medium, and method for radially-dependent noise reduction in image capturing devices involving an edge-preserving blur window are disclosed. In one embodiment, the edge-preserving blur includes only those pixels in the blur window that are within a threshold value of the blur window's current center pixel in its blurring calculation.

By creating a threshold function that varies radially from the center of the image sensor's light intensity falloff function, a more appropriate threshold value can be chosen for each pixel, allowing for more noise farther from the center of the image, and allowing for less noise closer to the center of the image. Light-product information taken from the image's metadata may be used to scale the threshold value parameters dynamically. This allows the method to perform the appropriate amount of processing depending on the lighting situation of the image that is currently being processed.

Here's Apple's background on the invention: "Today, many personal electronic devices come equipped with digital cameras. Often, these devices perform many functions, and, as a consequence, the digital image sensors included in these devices must often be smaller than sensors in conventional cameras. The digital image sensor, such as a charge-coupled device (CCD), of a digital camera has a plurality of photo-sites arranged in a colored filtered array or pattern, such as a RGB Bayer pattern. In the RGB Bayer pattern, each photo-site is filtered so that it is receptive to either: red, green, blue, or some variation thereof.

"The type of colored filter array and digital imaging sensor varies, typically based on the manufacturer of the digital camera. For example, some color filtered arrays use a pattern of yellow, cyan, green, and magenta. Typically, the digital camera has an image pipeline that performs a demosaicing or de-Bayering process on the image, lens correction, and noise reduction. The image pipeline then performs RGB gamma correction and tone mapping on the image data and encodes the image into the YCbCr family of color spaces or other format suitable for displaying and viewing.

"Various considerations must be addressed when processing a digital image obtained with a digital camera, digital video camera, or other imaging device. One consideration involves the large amount of image noise resultant from the use of small camera sensors, due to their typically smaller image sensor sites. Increased noise in pixels is typically caused by the random arrival times of visible light photons to the sensor photosites, but may also be caused by the process of reading the pixel values from the sensor photosites, or for any number of other reasons, and is usually made worse by low light conditions. Although noise can lead to a grainy appearance in images due to the pattern of the color filter array, increased noise also leads to increased false colors in images.

Due to a phenomenon known as 'lens falloff,' the amount of light reaching off-center positions of a sensor is often less than the amount of light reaching the more central positions of the sensor. This imaging phenomenon causes the image intensity to decrease radially toward the edges of an image, creating an effect known as 'vignetting.' The amount of vignetting present in an image depends upon the geometry of the lens and will vary with various lens properties such as focal length and f-stop.

"The vignetting effect is more apparent in lenses of lower f-stop (e.g., larger aperture), which are often used in consumer cameras and digital video recorders. Another consequence of the lens falloff effect is that there is often more noise found in pixels farther radially from the center of the sensor or, more precisely, farther radially from the center of the sensor's light intensity falloff function, which may or may not be at the geometric center of the sensor.

"To correct for this lens falloff phenomenon, a technique known as 'flat fielding' can be performed which compensates for the different gains and dark current levels over the surface of the detector. Once a detector has been appropriately flat-fielded, a uniform signal will create a uniform output. Due to the lens falloff effect, flat fielding often disproportionately boosts the intensities of pixels near the outer edges of the sensor so that they are in line with the intensities measured near the center of the sensor when exposed to the same uniform signal. As a consequence, the greater noise levels found in the pixels located closer to the outer edges of the sensor are also magnified to a greater degree than the noise levels in pixels near the center of the sensor.

"To compensate for reduced performance in smaller camera sensors, various processing techniques may be implemented. However, most existing noise reduction techniques either produce a blotchy appearance in the images or are too computationally expensive to be used. Thus, there is need for a low computational cost, radially-based system and method for reducing noise effects in image capturing applications to create more visually appealing images."

The inventors are Mark Zimmer, Ralph Brunner and David Hayworth.


Community Search:
MacTech Search:

Software Updates via MacUpdate

Markly 1.5.3 - Create measurement and de...
Markly is a measurement and design-spec plugin/extension for Photoshop and Sketch. It is made for modern Web designers and app front-end developers. You can add specification marks simply by clicking... Read more
Suitcase Fusion 6 17.3.0 - Font manageme...
Suitcase Fusion 6 is the creative professional's font manager. Every professional font manager should deliver the basics: spectacular previews, powerful search tools, and efficient font organization... Read more
Nisus Writer Pro 2.1.2 - Multilingual wo...
Nisus Writer Pro is a powerful multilingual word processor, similar to its entry level products, but brings new features such as table of contents, indexing, bookmarks, widow and orphan control,... Read more
calibre 2.40.0 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
Vivaldi - An advanced browser...
Vivaldi is a browser for our friends. In 1994, two programmers started working on a web browser. Our idea was to make a really fast browser, capable of running on limited hardware, keeping in mind... Read more
OmniPlan 3.0 - Robust project management...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Yummy FTP 1.11 - FTP/SFTP/FTPS client fo...
Yummy FTP is an FTP + SFTP + FTPS file transfer client which focuses on speed, reliability and productivity. Whether you need to transfer a few files or a few thousand, schedule automatic backups, or... Read more
Tweetbot 2.1 - Popular Twitter client. (...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
MacPilot 8.0 - Enable over 1,200 hidden...
MacPilot gives you the power of UNIX and the simplicity of Macintosh, which means a phenomenal amount of untapped power in your hands! Use MacPilot to unlock over 1,200 features, and access them all... Read more
Typinator 6.7 - 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

Balloony Land offers a fresh twist on th...
Balloony Land by Palringo offers a fresh twist on the match three genre and is out now on iOS and Android. First-off, you'll be popping balloons instead of crushing candy and the balloons will float up and fill the empty spaces instead of dropping... | Read more »
Graphic - vector illustration and design...
Graphic - vector illustration and design 1.0 Device: iOS iPhone Category: Productivity Price: $2.99, Version: 1.0 (iTunes) Description: Autodesk Graphic is a powerful full-featured vector drawing and illustration application right in... | Read more »
Sago Mini Babies (Education)
Sago Mini Babies 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: Introducing the Sago Mini babies. Boys and girls love caring for these adorable characters. Feed Robin her favorite mush... | Read more »
PAUSE - Relaxation at your fingertip (H...
PAUSE - Relaxation at your fingertip 1.1 Device: iOS iPhone Category: Healthcare & Fitness Price: $1.99, Version: 1.1 (iTunes) Description: | Read more »
Super Sharp (Games)
Super Sharp 1.1 Device: iOS Universal Category: Games Price: $1.99, Version: 1.1 (iTunes) Description: Your finger has never been so sharp! Cut with skill to complete the 120 ingenious physics levels of Super Sharp and become a cut... | Read more »
Assembly - Graphic design for everyone...
Assembly - Graphic design for everyone 1.0 Device: iOS Universal Category: Photography Price: $2.99, Version: 1.0 (iTunes) Description: Assembly is the easiest most powerful design tool on the App Store. Create anything you can... | Read more »
Dub Dash (Games)
Dub Dash 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: ARE YOU READY FOR THE ULTIMATE CHALLENGE? UNIQUE SYMBIOSIS OF MUSIC AND GRAPHICS | Read more »
Leave Me Alone (Games)
Leave Me Alone 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: 33% off launch sale!!! Somewhere between the 1980s and 1990s there exists a world that never was. A world of skatepunks,... | Read more »
YAMGUN (Games)
YAMGUN 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: The invasion has begun! Protect the walls of the citadel against waves of enemies! But watch out, you will soon run out of ammo...... | Read more »
Chesh (Games)
Chesh 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: It’s like chess, only not at all. ***40% off for a limited time to celebrate our launch!*** Chesh is a game of skill, strategy, luck,... | Read more »

Price Scanner via

TP-LINK Next-Gen Routers Support a Large Numb...
TP-LINK, specialists in consumer and business networking products, have announced the availability of Archer C2600, the company’s next-generation router featuring wireless AC, multi-user MIMO, and 4-... Read more
Apple’s Education discount saves up to $300 o...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and... Read more
Save up to $350 with Apple refurbished iMacs
Apple has Certified Refurbished iMacs available for up to $350 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 27″ 3.5GHz 5K iMac – $1949 $350 off MSRP - 27... Read more
Mac Pros on sale for up to $300 off MSRP
B&H Photo has Mac Pros on sale for up to $300 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2818.99, $181 off MSRP - 3.5GHz 6-core Mac Pro: $3699... Read more
5K iMacs on sale for up to $150 off MSRP, fre...
B&H Photo has the 27″ 3.3GHz 5K iMac on sale for $1899.99 including free shipping plus NY tax only. Their price is $100 off MSRP. They have the 27″ 3.5GHz 5K iMac on sale for $2149, $150 off MSRP... Read more
Twelve South Redesigns BookArc For Today’s Sm...
Twelve South has announced a redesigned version of their very first product, BookArc for MacBook. Tailored specifically for the newest generation of MacBooks, BookArc holds the new, smaller Apple... Read more
Phone 6s Tips & Tricks – Tips Book For iP...
Poole, United Kingdom based Tap Guides Ltd. has announced the release and immediate availability of iPhone 6s Tips & Tricks, an in-depth eBook available in the iBookstore that’s priced just $2.99... Read more
Apple refurbished 2014 13-inch Retina MacBook...
Apple has Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and shipping is free... Read more
13-inch 2.5GHz MacBook Pro on sale for $994,...
Best Buy has the 13″ 2.5GHz MacBook Pro available for $994.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $105 off MSRP. Price valid... Read more
Is The iPad Pro Really A Serious Laptop Repla...
Probably not, at least for productive professionals and other power users. Steve Jobs declared that we’d entered the “post-PC Era” with the advent of the original iPad in 2010, a phrase we don’t hear... Read more

Jobs Board

*Apple* Desktop Analyst - KDS Staffing (Unit...
…work with some of the brightest engineers. Job Description Title: Apple Desktop AnalystPosition Type: Full-time PermanentLocation: White Plains, NYHot Points:Depth of Read more
*Apple* Retail Online, Customer Experience R...
**Job Summary** Apple Retail's Online Store sells Apple products to customers around the world. In addition to selling Apple products with unique services such Read more
Frameworks Engineer, *Apple* Watch - Apple...
**Job Summary** Join the team that is shaping the future of software development for Apple Watch! As a software engineer on the Apple Watch Frameworks team you will Read more
Senior Manager, Global Direct Marketing *App...
**Job Summary** Apple Retail is looking for an experienced Direct Marketing Leader to join its Marketing team. This position will take a leadership role in creating Read more
*Apple* Online Store Expansion - Apple (Unit...
**Job Summary** The Online Apple Store is seeking a person to lead its expansion into new countries. Based in Cupertino, CA, this person will develop and maintain an Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.