Patents by Inventor Man Cheung
Man Cheung has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8208216Abstract: Methods, systems and computer program products for detecting an end of a reference spiral band are described. In some implementations, a band of spirals and servo information are written onto a storage medium. One or more characteristics associated with the band of spirals are determined. Then, one or more spirals of the band of spirals are identified as reference spirals based on the one or more determined characteristics. The writing of at least one of the band of spirals and the servo information is terminated upon identifying the one or more reference spirals.Type: GrantFiled: July 12, 2010Date of Patent: June 26, 2012Assignee: Marvell International Ltd.Inventors: Perry Neos, Luan Ton-That, Man Cheung
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Patent number: 8194343Abstract: Systems, methods, and apparatuses, including computer program products, are described for, in at least one implementation, determining a measured slope of a spiral, calibrating radial spacing between servo tracks according to a relationship between a target slope and the measured slope, wherein an amount of calibration for the radial spacing varies directly with the relationship between the target slope and the measured slope, and generating servo tracks according to the calibrated radial spacing.Type: GrantFiled: July 16, 2010Date of Patent: June 5, 2012Assignee: Marvell International Ltd.Inventors: Jason Adler, David Rutherford, Man Cheung, Perry Neos, Luan Ton-That
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Patent number: 8184392Abstract: Methods, systems, and apparatus, including computer program products are described for calibrating servos, and in some implementations, calibrating spiral servos for use in self-servo-write (SSW) processes. In one aspect, a method is provided that includes determining timing reference information on a machine readable medium, locking a clock signal to the timing reference information, detecting a spiral on the machine readable medium, determining a location of the spiral using the clock signal, and calibrating a spiral servo according to the location of the spiral.Type: GrantFiled: November 7, 2011Date of Patent: May 22, 2012Assignee: Marvell International Ltd.Inventors: Man Cheung, David Rutherford, Jerry Richgels, Perry Neos
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Publication number: 20120072167Abstract: Accurate and reliable techniques for determining a current status of an accessory device in relation to an electronic device are described.Type: ApplicationFiled: February 28, 2011Publication date: March 22, 2012Applicant: APPLE INC.Inventors: Michael A. CRETELLA, JR., Venu Madhav DUGGINENI, Michael Man-Cheung ENG, Ronald Keryuan HUANG, Christopher MOORE, Christopher T. MULLENS
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Publication number: 20120062756Abstract: Multiview videos are acquired by overlapping cameras. Side information is used to synthesize multiview videos. A reference picture list is maintained for current frames of the multiview videos, the reference picture indexes temporal reference pictures and spatial reference pictures of the acquired multiview videos and the synthesized reference pictures of the synthesized multiview video. Each current frame of the multiview videos is predicted according to reference pictures indexed by the associated reference picture list with a skip mode and a direct mode, whereby the side information is inferred from the synthesized reference picture. Alternatively, the depth images corresponding to the multiview videos of the input data, and this data are encoded as part of the bitstream depending on a SKIP type.Type: ApplicationFiled: November 17, 2011Publication date: March 15, 2012Inventors: Dong Tian, Ngai-Man Cheung, Anthony Vetro
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Patent number: 8111760Abstract: Deblock filtering for Microsoft WMV video decoders partitions the computation so that the deblock filtering operations can be performed on horizontal or vertical stripes or in one pass on oversized macroblocks.Type: GrantFiled: November 16, 2006Date of Patent: February 7, 2012Assignee: Texas Instruments IncorporatedInventors: Ching-Yu Hung, Ngai-Man Cheung
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Publication number: 20120008865Abstract: A system and method is provided for automatically recognizing building numbers in street level images. In one aspect, a processor selects a street level image that is likely to be near an address of interest. The processor identifies those portions of the image that are visually similar to street numbers, and then extracts the numeric values of the characters displayed in such portions. If an extracted value corresponds with the building number of the address of interest such as being substantially equal to the address of interest, the extracted value and the image portion are displayed to a human operator. The human operator confirms, by looking at the image portion, whether the image portion appears to be a building number that matches the extracted value. If so, the processor stores a value that associates that building number with the street level image.Type: ApplicationFiled: July 12, 2011Publication date: January 12, 2012Applicant: Google Inc.Inventors: Bo Wu, Alessandro Bissacco, Raymond W. Smith, Kong man Cheung, Andrea Frome, Shlomo Urbach
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Patent number: 8094405Abstract: Methods, systems and computer program products for compensating repeatable run-out (RRO) are described. In some implementations, RRO may be compensated by predicting the RRO and subsequently subtracting the predicted RRO from the actual value of the RRO to cancel out the undesired effect caused by the RRO during operation. More specifically, RRO generated at each spindle motor rotation may be predicted by measuring the position errors associated with the RRO with respect to a current position of a read/write head. A computational model then may be utilized to determine one or more correction factors to compensate for the RRO.Type: GrantFiled: October 24, 2008Date of Patent: January 10, 2012Assignee: Marvell International Ltd.Inventors: Edward Ying, Pantas Sutardja, Man Cheung
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Patent number: 8085492Abstract: The present disclosure includes systems and techniques relating to magnetic recording devices, such as disk drives. A recording medium of a magnetic recording device can include multiple helicoid patterns arranged in multiple helicoid groups. A described technique includes receiving a waveform produced by a head operated with respect to the medium; determining, based on the waveform, first phase difference(s) corresponding to a first helicoid group; affecting an alignment of the head with respect to the medium based on the first helicoid group by compensating for the first phase difference(s) to maintain the alignment; determining, while compensating for the first phase differences, second phase difference(s) corresponding to a second helicoid group; and affecting, responsive to a switch from the first helicoid group to the second helicoid group, the alignment of the head with respect to the medium by compensating for the second phase difference(s) to maintain the alignment.Type: GrantFiled: December 20, 2010Date of Patent: December 27, 2011Assignee: Marvell International Ltd.Inventors: Man Cheung, Perry Neos, David Rutherford
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Patent number: 8068304Abstract: Methods, systems, and apparatus, including computer program products are described for calibrating servos, and in some implementations, calibrating spiral servos for use in self-servo-write (SSW) processes. In one aspect, a method is provided that includes determining timing reference information on a machine readable medium, locking a clock signal to the timing reference information, detecting a spiral on the machine readable medium, determining a location of the spiral using the clock signal, and calibrating a spiral servo according to the location of the spiral.Type: GrantFiled: August 15, 2008Date of Patent: November 29, 2011Assignee: Marvell International Ltd.Inventors: Man Cheung, David Rutherford, Jerry Richgels, Perry Neos
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Patent number: 8023216Abstract: Methods, systems, and apparatus, including computer program products are described for calibrating servos, and in some implementations, calibrating spiral servos for use in self-servo-write SSW processes. In one aspect, a method is provide that includes rotating a machine readable medium, and detecting a spiral on the machine readable medium. Detecting a spiral on the machine readable medium includes detecting magnitudes of the spiral and a timing mark, storing a timestamp from a clock signal that corresponds to the timing mark of the spiral, determining a peak of the spiral from the magnitudes, and locking the clock signal to the peak of the spiral using the timestamp.Type: GrantFiled: August 15, 2008Date of Patent: September 20, 2011Assignee: Marvell International Ltd.Inventors: Man Cheung, David Rutherford, Jerry Richgels, Perry Neos
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Patent number: 7944638Abstract: A method for dynamic spiral ISR scheduling determines a dynamic delay with spiral to spiral spacing information of a disk, so as to ensure that the sum of a primary ISR time and a secondary ISR time does not exceed the wedge to wedge time. The ISR time may be scheduled to start after a delay for the sum of a static delay and the dynamic delay from an edge. A system for dynamic spiral ISR scheduling uses a dynamic delay determining unit to determine a dynamic delay, and an ISR scheduling unit to schedule the start of a secondary spiral set ISR based on a sum of the dynamic delay and a static delay.Type: GrantFiled: December 21, 2009Date of Patent: May 17, 2011Assignee: Marvell International Ltd.Inventors: Man Cheung, Perry Neos, Luan Ton-That
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Patent number: 7881005Abstract: A servo control system includes an input that receives spiral signals generated by reading spirals that are prewritten on a magnetic medium. The servo control system further includes a control module that generates spiral correction values for the spirals based on the spiral signals and that determines positions of the spirals based on the spiral correction values.Type: GrantFiled: August 8, 2008Date of Patent: February 1, 2011Assignee: Marvell International Ltd.Inventors: Man Cheung, Perry Neos
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Patent number: 7869158Abstract: A recording medium can include multiple helicoid patterns arranged in multiple helicoid groups, e.g., first and second helicoid groups. Operating a disk drive can include switching between helicoid groups to maintain the alignment of the head with respect to a target track of the rotating recording medium. Enabling a switch can include receiving a waveform produced by a head operated with respect to a rotating recording medium, generating first information from one or more portions of the waveform corresponding to the helicoid patterns of the first helicoid group; generating second information from one or more portions of the waveform corresponding to the helicoid patterns of the second helicoid group; and analyzing the second information with respect to the first information to generate calibration information. The calibration information can compensate for operational differences between using the helicoid patterns of the first helicoid group and the helicoid patterns of the second helicoid group.Type: GrantFiled: August 15, 2008Date of Patent: January 11, 2011Assignee: Marvell International Ltd.Inventors: Man Cheung, Perry Neos, David Rutherford
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Publication number: 20100322306Abstract: Systems, methods, and apparatus for adaptively zeroing out transform coefficients utilizing a bit-stealing parameter are presented herein. A partitioning component can be configured to separate an image into blocks of video data. Further, a frequency transform component can be configured to transform pixels of a block of the blocks into transform coefficients. Furthermore, a bit-stealing quantization component configured to predefine quantization intervals. Moreover, the bit-stealing quantization component can modify a size of a quantization interval of the quantization intervals based on a variable bit-stealing parameter. Further, the bit-stealing component can quantize a transform coefficient of the transform coefficients, based on the quantization interval, to a quantized coefficient value of quantized coefficient values.Type: ApplicationFiled: June 18, 2010Publication date: December 23, 2010Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGYInventors: Oscar Chi Lim Au, Ngai Man Cheung, Xingyu Zhang
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Patent number: 7791832Abstract: A control system includes a write head and a control module configured to signal the write head to write a servo test track on a rotating medium at a position relative to a reference servo track on the rotating medium. The servo test track is written on the rotating medium subsequent to an interrupt event. The reference servo track having been written to the rotating medium prior to the interrupt event, detects the position of the servo test track relative to the reference servo track and signals the write head to write a new servo track on the rotating medium based on the detected position of the servo test track relative to the reference servo track.Type: GrantFiled: January 11, 2010Date of Patent: September 7, 2010Assignee: Marvell International Ltd.Inventors: Man Cheung, Pantas Sutardja
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Patent number: 7773335Abstract: Methods, systems, and apparatus, including computer program products, are described for calibrating servos, and in some implementations for calibrating spiral servos for use in self-servo-write processes. In one aspect, a method is provided that includes determining a measured slope of a spiral, and calibrating radial spacing between servo tracks using the measured slope and a target slope.Type: GrantFiled: August 15, 2008Date of Patent: August 10, 2010Assignee: Marvell International Ltd.Inventors: Jason Adler, David Rutherford, Man Cheung, Perry Neos, Luan Ton-That
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Patent number: 7764457Abstract: Methods, systems and computer program products for detecting an end of a reference spiral band are described. A first portion of servo information may be written on a disk using the reference spiral band. By detecting an end of a reference spiral band, a new reference spiral band may be launched. A read/write head of a hard disk drive may subsequently use the new spiral band to write the remaining portion of the servo information, which aids the writing of data tracks on the disk.Type: GrantFiled: August 7, 2008Date of Patent: July 27, 2010Assignee: Marvell International Ltd.Inventors: Perry Neos, Luan Ton-That, Man Cheung
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Patent number: 7720151Abstract: This invention is a method for speeding up block matching based motion estimation for video encoder. The invention 1) calculates statistics for a candidate motion vector for a predetermined fraction of the pixels of a macroblock, 2) makes an early decision based on this preliminary cost function, and 3) terminates the block matching process without calculating the cost function for other pixels if the preliminary cost function is not less than a predetermined threshold. This early decision for goodness estimation provides an economy of processing load when a large portion of data is left untouched (i.e. unprocessed). The present invention employs feedback control to reduce the predetermined threshold for quick convergence upon each detection of a better match.Type: GrantFiled: February 11, 2003Date of Patent: May 18, 2010Assignee: Texas Instruments IncorporatedInventors: Yuji Itoh, Ho-Cheon Wey, Ngai-Man Cheung
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Publication number: 20100020877Abstract: Multiple reference frame motion estimation for video frame blocks is provided. A plurality of copies of a block list of a reference frame can be loaded into texture memory. Encoding of video blocks of the video frame can be ordered to allow concurrent encoding of the video blocks. Furthermore, motion vector prediction can be performed concurrently for independent video blocks, the motion vectors can be related to each one of the plurality of copies of the block list of the reference frame and determined for the at least a portion of the plurality of blocks ordered for concurrent encoding. Additionally, a fast motion estimation algorithm can be concurrently performed on a number of video blocks to search surrounding blocks and compute motion vectors. Further, concurrent processing of multiple slices can be performed. Such concurrent processes can leverage the parallel architecture of at least one graphical processing unit.Type: ApplicationFiled: July 23, 2008Publication date: January 28, 2010Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGYInventors: Oscar Chi Lim Au, Man Cheung Kung