Apple Patents Image Preprocessing for Mobile Devices

By Steve Brachmann
January 25, 2013

This Tuesday, Apple Inc. was once again the recipient of a number of issued patents, as 26 patents were awarded to the company. As we’ll see, a number of these are related to improvements in resource efficiency, especially those tailored to mobile devices like the iPhone. Apple also received a patent that may save many iPhone users hours of time: a system that automatically syncs important account data with a new device when replacing a broken or outdated model.

Image Preprocessing

U.S. Patent No. 8358812

U.S. Patent No. 8358813

Photo editing applications available on mobile devices typically have very low functionality compared to similar software available for desktop and even laptop computers. With these two patents, Apple Inc. hopes to empower mobile application developers who want to offer better editing features on these devices, which are increasingly being used to capture images.

These patents protect a system of preprocessing images wherein an image file is analyzed for both color and facial recognition. The photo analysis application would allow a mobile device to perform these functions efficiently without draining battery resources. Increasing the efficiency of resource use also enables Apple to create applications in the future that include even more editing functions.

As claim 1 of patent #8358812 describes, Apple is protecting:

“A method performed by a software process executing on a computer system, the method comprising: accessing a digital image in the RGB color space, the digital image comprising a plurality of pixels, each pixel having a red component value, R, a blue component value, B, and a green component value, G; without transforming the digital image to another color space, identifying each pixel in the digital image for which a red component value is greater than or equal to a green component value, R?G, and for which the green component value is greater than a blue component value, G?B, for each identified pixel, calculating a chroma value by subtracting the pixel’s blue component value from the pixel’s red component value, R?B, and determining whether the digital image depicts human skin based at least in part on determining whether the calculated chroma value is within a predetermined value range; and generating a temporary image by masking a plurality of pixels of the digital image for which the chroma value is outside of the predetermined value range.”

Along with this system of color detection for images, claim 1 of patent #8358813 also protects:

“A method performed by a software process executing on a computer system, the method comprising: accessing a digital image comprising a plurality of pixels; for a first rectangular sub-region of the digital image, examining, by a hardware processor, only pixels bounding the first rectangular sub-region, wherein the first rectangular sub-region has a predetermined size and includes one or more pixels different from the bounding pixels, and determining, by the hardware processor based on said examining only the bounding pixels of the first rectangular sub-region, that a predetermined percentage of the bounding pixels satisfy a specified criterion; and selectively performing, by the hardware processor, a face detection algorithm on the digital image, wherein the face detection algorithm is performed on the first rectangular sub-region by treating, in response to said determining that the predetermined percentage of the bounding pixels satisfy the specified criterion, all pixels within the first rectangular sub-region as also satisfying the specified criterion.”

Noise Cancellation for Microphone-Speaker Combinations Using Combined Speaker Amplifier and Reference Sensing

U.S. Patent No. 8358788

Many iPhone users who use headsets may be familiar with the echo that occurs at times which repeats the speaker’s words a second or two after they’re spoken. This can seriously hamper clear conversation between parties as this can disorient the speaker.

This is actually caused by slight internal design flaws in a mobile device. Often, the headset jack input is located relatively far away from the logic board where audio processing occurs. Routing the signal across various circuit boards can compromise the headset signal and create signal noise that the speaker hears as an echo. Apple’s patent describes a system of eliminating this particular signal noise by creating a system of detecting signal issues and amplifying the microphone signal to compensate. As the first claim of this patent describes, this patent protects:

“An audio host device comprising: an electrical interface having a speaker contact, a microphone contact, and a reference contact, the reference contact to be shared by a microphone and a speaker, the reference contact being directly coupled to a power return plane of the audio host device; a speaker amplifier having an output that is coupled to the speaker contact; and a difference amplifier having a first cold input, a second cold input, and a hot input, the first cold input is coupled to an output of the speaker amplifier, the second cold input being coupled to a sense point for the reference contact, and the hot input being coupled to the microphone contact.”


Data Filtering Using Central DMA Mechanism

U.S. Patent No. 8359411 

The central processing unit (CPU) of a mobile device is one of the largest battery resource drains, as the CPU utilizes a tremendous amount of power in order to run applications and other software on the device. One way to save resources and increase the productivity of the CPU would be to create a direct memory access (DMA) controller that operates a list of instructions handed over by the CPU, leaving that unit free to move on to other tasks.

Retrieving and accessing programs found in hard disk drive storage or other media uses a lot of resources, and additional user commands can overburden the CPU. The DMA controller would receive instructions from the CPU to retrieve a file or transmit data and carry out those instructions independent of the CPU.

Claim 1 of this patent for Apple protects:

“A direct memory access (DMA) controller, comprising: a control circuit adapted to receive device control information and to generate DMA transfer signals; an offload filter adapted to receive DMA transferred data and convert the DMA transferred data into processed data without the use of memory buffers in the DMA controller; and a plurality of DMA channel interface circuits adapted to receive the DMA transfer signals and the processed data”


Migration of Data Between Computers

U.S. Patent No. 8359375

Smartphones and other mobile devices offer users the capability to access and track many different online accounts through various software applications that can be downloaded directly to the device. However, in the event that an iPhone owner has to replace the device, much of this information is lost and must be manually reset on a new device.

Apple’s patent provides for a system of automatically migrating certain configuration data across computer systems. This data could include user names, passwords, network settings or application preferences. Once the replacement device is identified by the computer system, the source device is booted up and the data is transmitted directly to the replacement device. As claim 1 of this patent describes, Apple is protecting:

“A computer-implemented method comprising: searching a plurality of paths and sub-paths arranged in a file system hierarchy on a source electronic device according to a path analysis option to locate files containing data and applications corresponding to a user, wherein the searching comprises analyzing the sub-paths to a maximum depth in the file system hierarchy, the source electronic device having at least user-specific system configuration data corresponding to the user and operation of the source electronic device, and wherein the path analysis option indicates a path to be included in the search or a path to be excluded from the search; including the user-specific system configuration data found through the searching in a copy list; and transferring data corresponding to the copy list from the source electronic device to a destination electronic device.”


Method for Dynamically Generating a “Table of Contents” View of the HTML-Based Information System

U.S. Patent No. 8359550

This patent pertains specifically to indexes created for help topics created for online programs which aid users during operation. These help topic indexes, often styled as a Table of Contents, usually utilize HTML linking for subject headings. This allows a user to click the topic and directly access the help information in a new window, keeping information retrieval simple and easy. When a user adjusts any of the files within the help application, the HTML-based links can become broken if they’re not updated to account for any file path changes.

The system created by Apple, and protected by this patent, is much more reflexive to changes in the file hierarchy accessed by the help application. A Table of Contents would be automatically updated to reflect data changes, meaning user access of help information won’t be hindered by program updates.

As is described by the first claim in this patent, Apple is protecting:

“A method for dynamically generating a table-of-contents for an information system, the method comprising: detecting a user-selection of one of a plurality of folders, said folders including source files related to a corresponding topic in a table-of-contents; identifying one or more source files in the selected folder for inclusion in the table-of-contents; identifying meta-tags associated with the identified source files; selectively merging, based on the identified meta-tags, data associated with the identified meta-tags into a table-of-contents template; generating a table-of-contents record containing the merged data associated with the identified meta-tags; and causing the display of, in accordance the table-of-contents record, a table-of-contents for the topic corresponding to the selected folder.”

The Author

Steve Brachmann

Steve Brachmann is a writer located in Buffalo, New York. He has worked professionally as a freelancer for more than a decade. He has become a regular contributor to, writing about technology, innovation and is the primary author of the Companies We Follow series. His work has been published by The Buffalo News, The Hamburg Sun,,, Motley Fool and Steve also provides website copy and documents for various business clients.

Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author and should not be attributed to the author’s employer, clients or the sponsors of Read more.

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