Patents by Inventor Jiefu Zhai
Jiefu Zhai 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: 9264661Abstract: A system may include a receiver, a decoder, a post-processor, and a controller. The receiver may receive encoded video data. The decoder may decode the encoded video data. The post-processor may perform post-processing on frames of decoded video sequence from the decoder. The controller may adjust post-processing of a current frame, based upon at least one condition parameters detected at the system.Type: GrantFiled: November 18, 2013Date of Patent: February 16, 2016Assignee: Apple Inc.Inventors: Jiefu Zhai, Chris Y. Chung, Xiaosong Zhou, Hsi-Jung Wu
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Patent number: 9215466Abstract: A video coder employs techniques for applying frame rate adaptation and variable resolution adaptation in response to environmental coding factors present at the coding terminal. According to such techniques, a coder may estimate a coding quality level to be applied based on the environmental coding factors. The coder may retrieve from a controller table, settings for resolution and frame rate based on the estimated quality level. Optionally, the coder further may retrieve settings identifying a range of quantization parameters that may be used during coding. Prior to coding, the coder may configure input video data to match the resolution and frame rate settings retrieved from the controller table. Thereafter, the coder may code the reconfigured input video data by motion-compensation prediction constrained, as applicable, by the retrieved quantization parameter range.Type: GrantFiled: January 31, 2011Date of Patent: December 15, 2015Assignee: Apple Inc.Inventors: Jiefu Zhai, Xiaosong Zhou, Hsi-Jung Wu
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Publication number: 20150350514Abstract: Systems and methods are provided for capturing high quality video data, including data having a high dynamic range, for use with conventional encoders and decoders. High dynamic range data is captured using multiple groups of pixels where each group is captured using different exposure times to create groups of pixels. The pixels that are captured at different exposure times may be determined adaptively based on the content of the image, the parameters of the encoding system, or on the available resources within the encoding system. The transition from single exposure to using two different exposure times may be implemented gradually.Type: ApplicationFiled: May 29, 2015Publication date: December 3, 2015Inventors: Jiefu Zhai, Xiaosong Zhou, Chris Y. Chung, Hsi-Jung Wu
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Publication number: 20150350687Abstract: Chroma deblock filtering of reconstructed video samples may be performed to remove blockiness artifacts and reduce color artifacts without over-smoothing. In a first method, chroma deblocking may be performed for boundary samples of a smallest transform size, regardless of partitions and coding modes. In a second method, chroma deblocking may be performed when a boundary strength is greater than 0. In a third method, chroma deblocking may be performed regardless of boundary strengths. In a fourth method, the type of chroma deblocking to be performed may be signaled in a slice header by a flag. Furthermore, luma deblock filtering techniques may be applied to chroma deblock filtering.Type: ApplicationFiled: May 29, 2014Publication date: December 3, 2015Applicant: Apple Inc.Inventors: Jiefu Zhai, Dazhong Zhang, Xiaosong Zhou, Chris Y. Chung, Hsi-Jung Wu, Peikang Song, David R. Conrad, Jae Hoon Kim, Yunfei Zheng
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Publication number: 20150350641Abstract: A video coding/decoding system codes data efficiently even when input video data exhibits changes in dynamic range. The system may map pixel values of the first frame from a dynamic range specific to the input image data to a second dynamic range that applies universally to a plurality of frames that have different dynamic ranges defined for them. The system may code the mapped pixel values to reduce bandwidth of the mapped frame data, and thereafter transmit the coded image data to a channel.Type: ApplicationFiled: March 3, 2015Publication date: December 3, 2015Inventors: Xiaosong Zhou, Jiefu Zhai, Yeping Su, Chris Y. Chung, Hsi-Jung Wu
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Publication number: 20150350686Abstract: A method and system of using a pre-encoder to improve encoder efficiency. The encoder may conform to ITU-T H.265 and the pre-encoder may conform to ITU-T H. 264. The pre-encoder may receive source video data and provide information regarding various coding modes, candidate modes, and a selected mode for coding the source video data. In an embodiment, the encoder may directly use the mode selected by the pre-encoder. In another embodiment, the encoder may receive both the source video data and information regarding the various coding modes (e.g., motion information, macroblock size, intra prediction direction, rate-distortion cost, and block pixel statistics) to simplify and/or refine its mode decision process. For example, the information provided by the pre-encoder may indicate unlikely modes, which unlikely modes need not be tested by the encoder, thus saving power and time.Type: ApplicationFiled: May 29, 2014Publication date: December 3, 2015Applicant: Apple Inc.Inventors: Xiaosong Zhou, Chris Y. Chung, David R. Conrad, Dazhong Zhang, Feng Yi, Hsi-Jung Wu, Jae Hoon Kim, Jiefu Zhai, Peikang Song, Yunfei Zheng
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Publication number: 20150326896Abstract: Systems and methods are provided for processing high quality video data, such as data having a higher than standard bit depth, a high dynamic range, or a wide or custom color gamut, to be compatible with conventional encoders and decoders without significant loss of quality. High quality data is encoded into a plurality of layers with a base layer having the standard quality data and one or more higher quality layers. Decoding systems and methods may map the base layer to the dynamic range or color gamut of the enhancement layer, combine the layers, and map the combined layers to a dynamic range or color gamut appropriate for the target display. Each of the standard quality and the high quality data may be encoded as a plurality of tiers of increasing quality and reference lower level tiers as sources of prediction during predictive coding.Type: ApplicationFiled: May 12, 2015Publication date: November 12, 2015Inventors: Yeping Su, Jiefu Zhai, Ke Zhang, Xiaosong Zhou, Hsi-Jung Wu, Chris Y. Chung
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Publication number: 20150302562Abstract: Various implementations address high dynamic range (“HDR”) images. In one particular implementation, a low dynamic range (“LDR”) image is generated from an HDR image, and information is generated allowing the HDR image to be reconstructed from the LDR image. The LDR image and the information are encoded. In another implementation, a signal or signal structure includes an LDR section including the encoded LDR image, and an information section including the encoded information. In another implementation, the encoded LDR image and the encoded information are both decoded. The HDR image is then reconstructed based on the decoded LDR image and the decoded information.Type: ApplicationFiled: November 16, 2012Publication date: October 22, 2015Inventors: Jiefu ZHAI, Zhe WANG, Dong Tian
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Patent number: 9087382Abstract: A method of tone mapping high dynamic range images for display on low dynamic range displays wherein a high dynamic range image is first accessed. The high dynamic range image is segmented into different regions such that each region is represented by a matrix, where each element of the matrix is a weight or probability of a pixel. An exposure of each region is determined or calculated and the exposure values are applied to the regions responsive to the weight or probability. The different regions are then fused together to obtain a final tone mapped image.Type: GrantFiled: June 29, 2010Date of Patent: July 21, 2015Assignee: THOMSON LICENSINGInventors: Jiefu Zhai, Joan Llach
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Patent number: 8965118Abstract: A system and method for reducing chromatic aberration by aligning pixel in a color channel according to displacement from corresponding pixels in another color channel. In particular, the system calculates a feature, such as intensity, for a first block of pixels in a first color channel of an image. The feature is calculated for a second block of pixels in a second color channel of the image. Displacement is estimated between the first color channel and the second color channel by comparing the feature for the first block and the feature for the second block. At least a portion of the first color channel is aligned with at least a portion of the second color channel based on the estimated displacement.Type: GrantFiled: February 7, 2011Date of Patent: February 24, 2015Assignee: Thomson LicensingInventors: Jiefu Zhai, Zhe Wang, Tao Zhang
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Publication number: 20140362159Abstract: A system may include a receiver, a decoder, a post-processor, and a controller. The receiver may receive encoded video data. The decoder may decode the encoded video data. The post-processor may perform post-processing on frames of decoded video sequence from the decoder. The controller may adjust post-processing of a current frame, based upon at least one condition parameters detected at the system.Type: ApplicationFiled: November 18, 2013Publication date: December 11, 2014Applicant: Apple Inc.Inventors: Jiefu Zhai, Chris Y. Chung, Xiaosong Zhou, Hsi-Jung Wu
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Patent number: 8897580Abstract: YCbCr image data may be dithered and converted into RGB data shown on a 8-bit or other bit display. Dither methods and image processors are provided which generate the banding artifact free image data during this process. Some methods and image processors may applying a stronger dither having a same mean with a larger variance to the image data before it is converted to RGB data. Others methods and image processors may calculate a quantization or encoding error and diffuse the calculated error among one or more neighboring pixel blocks.Type: GrantFiled: October 30, 2012Date of Patent: November 25, 2014Assignee: Apple Inc.Inventors: Yeping Su, Jiefu Zhai, James Oliver Normile, Hsi-Jung Wu, Hao Pan
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Patent number: 8737738Abstract: A method for toning mapping high dynamic range (HDR) video for display in low dynamic range display comprises accessing the HDR video; producing a luminance information for the individual frames; partitioning different consecutive groups of frames into segments responsive to the luminance information; classifying the segments into static luminance segments and transient luminance segments; producing a tone mapping parameter set for the static luminance segments; producing a tone mapping parameter set for at least one of the transient luminance segments responsive to the tone mapping parameter set of an adjacent static luminance segment; and tone mapping the static luminance segments and transient luminance segments according to the respective tone mapping parameter sets.Type: GrantFiled: February 11, 2011Date of Patent: May 27, 2014Assignee: Thomson LicensingInventors: Zhe Wang, Jiefu Zhai
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Publication number: 20140072029Abstract: An adaptive scaler switching system may implement multiple scalers including both a software scaler and a hardware scaler, and a controller that may manage the switch between scalers by considering the real-time constraints of the system and the available system resources. Information about the availability of system resources may be received in real-time, for example the controller may receive information about the system thermal status, the timing requirements for processing the video data, the quality of the scaled data, and any other relevant system statistics that may affect the scaler switch decision. According to an embodiment, the system may maintain statistics in a table, and update the table information as necessary.Type: ApplicationFiled: January 17, 2013Publication date: March 13, 2014Applicant: Apple Inc.Inventors: Jiefu ZHAI, Douglas PRICE, Albert KEINATH, Xiaosong ZHOU, Hsi-Jung WU
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Publication number: 20140029846Abstract: YCbCr image data may be dithered and converted into RGB data shown on a 8-bit or other bit display. Dither methods and image processors are provided which generate the banding artifact free image data during this process. Some methods and image processors may applying a stronger dither having a same mean with a larger variance to the image data before it is converted to RGB data. Others methods and image processors may calculate a quantization or encoding error and diffuse the calculated error among one or more neighboring pixel blocks.Type: ApplicationFiled: October 30, 2012Publication date: January 30, 2014Applicant: APPLE INC.Inventors: Yeping SU, Jiefu ZHAI, James Oliver NORMILE, Hsi-Jung WU, Hao PAN
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Patent number: 8639056Abstract: A method according to the invention enhances contrast of an image by accessing an original image, and establishing, assigning, or initializing pixel values and pixel coordinates of pixels of the image. Then, a Laplacian pyramid having an integral number of levels is generated for the image. A contrast boost pyramid is generated and applied to the Laplacian pyramid to obtain a modified Laplacian pyramid wherein values in the levels of the Laplacian pyramid are enhanced. An enhanced image is then constructed from the modified Laplacian pyramid.Type: GrantFiled: June 28, 2010Date of Patent: January 28, 2014Assignee: Thomson LicensingInventors: Jiefu Zhai, Joan Llach
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Publication number: 20130258067Abstract: A depth acquisition system utilizes at least three sensors with at least one sensor in a non-colinear configuration to increase depth information. This configuration provides both vertical and horizontal depth information to be combined to enhance image quality, especially in three-dimensional image gathering. Vertical sensor pairs aid in determining disparities for horizontal edges and make depth estimations for horizontal edges more accurate.Type: ApplicationFiled: December 8, 2010Publication date: October 3, 2013Inventors: Dong-Qing Zhang, Jiefu Zhai, Zhe Wang
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Publication number: 20130235928Abstract: Embodiments of the present invention provide techniques for efficiently coding/decoding video data during circumstances when constraints are imposed on the video data. A frame from a video sequence may be marked as a delayed decoder refresh frame. Frames successive to the delayed decoder refresh frame in coding order may predictively coded without reference to frames preceding the delayed decoder refresh frame in coding order. The distance between the delayed decoder refresh frame and the successive frames may exceed a distance threshold. Frames successive to a current frame in decoding order may be decoded without reference to frames preceding the current frame in decoding order. The distance between the current frame and the successive frames may exceed a distance threshold.Type: ApplicationFiled: October 15, 2012Publication date: September 12, 2013Applicant: APPLE INC.Inventors: Chris Y. Chung, Hao Pan, Jiefu Zhai, Yeping Su, Douglas Scott Price, Hsi-Jung Wu, Xiaosong Zhou
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Publication number: 20130163868Abstract: A method for toning mapping high dynamic range (HDR) video for display in low dynamic range display comprises accessing the HDR video; producing a luminance information for the individual frames; partitioning different consecutive groups of frames into segments responsive to the luminance information; classifying the segments into static luminance segments and transient luminance segments; producing a tone mapping parameter set for the static luminance segments; producing a tone mapping parameter set for at least one of the transient luminance segments responsive to the tone mapping parameter set of an adjacent static luminance segment; and tone mapping the static luminance segments and transient luminance segments according to the respective tone mapping parameter sets.Type: ApplicationFiled: February 11, 2011Publication date: June 27, 2013Inventors: Zhe Wang, Jiefu Zhai
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Publication number: 20130141432Abstract: A method and system for calibration and compensation of color in a three dimensional display system includes user calibration of individual color channels using a multiplicity of grey screens while viewing with three dimensional glasses. Look-up tables are generated to ease conversion of input pixels to color corrected pixels to pre-distort the color of the pixels being driven by the three dimensional display system. Input pixels are then converted using the look-up tables and color corrected frames are displayed to a user. The pre-distortion effect allows a user to perceive colors in the three dimensional system as intended with the distortions caused by the viewing glasses and other aspects of the three dimensional display system.Type: ApplicationFiled: August 19, 2010Publication date: June 6, 2013Applicant: THOMSON LICENSINGInventors: Zhe Wang, Jiefu Zhai, Tao Zhang