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).

  • Publication number: 20150350641
    Abstract: 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: Application
    Filed: March 3, 2015
    Publication date: December 3, 2015
    Inventors: Xiaosong Zhou, Jiefu Zhai, Yeping Su, Chris Y. Chung, Hsi-Jung Wu
  • Publication number: 20150350686
    Abstract: 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: Application
    Filed: May 29, 2014
    Publication date: December 3, 2015
    Applicant: 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
  • Publication number: 20150350687
    Abstract: 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: Application
    Filed: May 29, 2014
    Publication date: December 3, 2015
    Applicant: 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
  • Publication number: 20150326896
    Abstract: 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: Application
    Filed: May 12, 2015
    Publication date: November 12, 2015
    Inventors: Yeping Su, Jiefu Zhai, Ke Zhang, Xiaosong Zhou, Hsi-Jung Wu, Chris Y. Chung
  • Publication number: 20150302562
    Abstract: 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: Application
    Filed: November 16, 2012
    Publication date: October 22, 2015
    Inventors: Jiefu ZHAI, Zhe WANG, Dong Tian
  • Patent number: 9087382
    Abstract: 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: Grant
    Filed: June 29, 2010
    Date of Patent: July 21, 2015
    Assignee: THOMSON LICENSING
    Inventors: Jiefu Zhai, Joan Llach
  • Patent number: 8965118
    Abstract: 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: Grant
    Filed: February 7, 2011
    Date of Patent: February 24, 2015
    Assignee: Thomson Licensing
    Inventors: Jiefu Zhai, Zhe Wang, Tao Zhang
  • Publication number: 20140362159
    Abstract: 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: Application
    Filed: November 18, 2013
    Publication date: December 11, 2014
    Applicant: Apple Inc.
    Inventors: Jiefu Zhai, Chris Y. Chung, Xiaosong Zhou, Hsi-Jung Wu
  • Patent number: 8897580
    Abstract: 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: Grant
    Filed: October 30, 2012
    Date of Patent: November 25, 2014
    Assignee: Apple Inc.
    Inventors: Yeping Su, Jiefu Zhai, James Oliver Normile, Hsi-Jung Wu, Hao Pan
  • Patent number: 8737738
    Abstract: 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: Grant
    Filed: February 11, 2011
    Date of Patent: May 27, 2014
    Assignee: Thomson Licensing
    Inventors: Zhe Wang, Jiefu Zhai
  • Publication number: 20140072029
    Abstract: 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: Application
    Filed: January 17, 2013
    Publication date: March 13, 2014
    Applicant: Apple Inc.
    Inventors: Jiefu ZHAI, Douglas PRICE, Albert KEINATH, Xiaosong ZHOU, Hsi-Jung WU
  • Publication number: 20140029846
    Abstract: 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: Application
    Filed: October 30, 2012
    Publication date: January 30, 2014
    Applicant: APPLE INC.
    Inventors: Yeping SU, Jiefu ZHAI, James Oliver NORMILE, Hsi-Jung WU, Hao PAN
  • Patent number: 8639056
    Abstract: 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: Grant
    Filed: June 28, 2010
    Date of Patent: January 28, 2014
    Assignee: Thomson Licensing
    Inventors: Jiefu Zhai, Joan Llach
  • Publication number: 20130258067
    Abstract: 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: Application
    Filed: December 8, 2010
    Publication date: October 3, 2013
    Inventors: Dong-Qing Zhang, Jiefu Zhai, Zhe Wang
  • Publication number: 20130235928
    Abstract: 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: Application
    Filed: October 15, 2012
    Publication date: September 12, 2013
    Applicant: APPLE INC.
    Inventors: Chris Y. Chung, Hao Pan, Jiefu Zhai, Yeping Su, Douglas Scott Price, Hsi-Jung Wu, Xiaosong Zhou
  • Publication number: 20130163868
    Abstract: 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: Application
    Filed: February 11, 2011
    Publication date: June 27, 2013
    Inventors: Zhe Wang, Jiefu Zhai
  • Publication number: 20130141432
    Abstract: 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: Application
    Filed: August 19, 2010
    Publication date: June 6, 2013
    Applicant: THOMSON LICENSING
    Inventors: Zhe Wang, Jiefu Zhai, Tao Zhang
  • Publication number: 20130091430
    Abstract: A tone mapping graphical user interface is provided that allows a video engineer to process a video using a set of tools for changing high dynamic range data into lower dynamic range data.
    Type: Application
    Filed: June 23, 2011
    Publication date: April 11, 2013
    Applicant: THOMSON LICENSING
    Inventors: Jiefu Zhai, Joan Llach, Zhe Wang
  • Patent number: 8385432
    Abstract: Scalable video coding based on H.264/AVC uses motion compensation, which results in motion vectors and residual pictures. To optimize the encoding of the residual pictures of the enhancement-layer, they can be predicted from the base-layer. This requires complex encoders and decoders. Simplified residual prediction techniques are provided that focus on reducing the encoding and decoding complexity of the spatial scalable enhancement-layer with optimized coding efficiency. The method for encoding video data containing high-pass frames and low-pass frames comprises the steps of encoding the low-pass frames, wherein residual prediction may be used, splitting the high-pass frames into two interleaving frame groups, encoding the frames of the first of said frame groups, wherein residual prediction may be used, and encoding the frames of the second of the frame groups using an encoding method without residual prediction.
    Type: Grant
    Filed: May 3, 2006
    Date of Patent: February 26, 2013
    Assignee: Thomson Licensing
    Inventors: Ying Chen, Jiefu Zhai, Kui Gao, Kai Xie
  • Patent number: 8346009
    Abstract: A method for tone mapping high dynamic range images for display on low dynamic range displays wherein high dynamic range images are first accessed. The high dynamic range images are divided the 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 value. An exposure of each region is determined or calculated by estimating an anchor point in each region such that most pixels in each region are mapped to mid grey and the anchor points are adjusted to a key of the images to preserve overall brightness. The regions are then placed or mapped to zones and exposure values are applied to the regions responsive to the weight or probability. The regions are fused together to obtain a final tone mapped image.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: January 1, 2013
    Assignee: Thomson Licensing
    Inventors: Jiefu Zhai, Joan Llach, Zhe Wang