Patents by Inventor Tihao Chiang
Tihao Chiang 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: 8498338Abstract: A method for video encoding is disclosed. The method generally includes the steps of (A) generating first sub-pel data for at least one of (i) a motion estimation and (ii) a mode decision by first filtering reference data and (B) generating second sub-pel data for a motion compensation by second filtering the reference data. Wherein a first performance of the first filtering may be different than a second performance of the second filtering.Type: GrantFiled: August 14, 2012Date of Patent: July 30, 2013Assignee: Ambarella, Inc.Inventors: Shih-Hao Wang, Leslie D. Kohn, Tihao Chiang
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Patent number: 8265151Abstract: A method for video encoding is disclosed. The method generally includes the steps of (A) generating first sub-pel data for at least one of (i) a motion estimation and (ii) a mode decision by first filtering reference data and (B) generating second sub-pel data for a motion compensation by second filtering the reference data. Wherein a first performance of the first filtering may be different than a second performance of the second filtering.Type: GrantFiled: December 14, 2005Date of Patent: September 11, 2012Assignee: Ambarella Taiwan Ltd.Inventors: Shih-Hao Wang, Leslie D. Kohn, Tihao Chiang
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Patent number: 8170124Abstract: An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.Type: GrantFiled: December 2, 2008Date of Patent: May 1, 2012Assignee: Industrial Technology Research InstituteInventors: Ming-Yen Huang, Tzu-Liang Su, Shih-Hao Wang, Chung-Neng Wang, Tihao Chiang
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Patent number: 7995659Abstract: A prediction module includes a computation control unit and first to sixth processing units. The computation control unit arranges the pixels of a reference block outputted by a frame buffer appropriately according to data decoded by an entropy decoder into first and second pixel signals, and outputs the same to the first to sixth processing units in units of cycles. The processing units are controlled by the computation control unit to respectively complete corresponding computations in a cycle, and to use the computation results as values of first to sixth output signals to be correspondingly outputted in a next cycle. The computation control unit receives the first to sixth output signals, and computes the output signals so as to obtain pixel values of a macroblock to be predicted.Type: GrantFiled: January 19, 2007Date of Patent: August 9, 2011Assignee: National Cheng Kung UniversityInventors: Chih-Chieh Chen, Chih-Hung Li, Wen-Hsiao Peng, Tihao Chiang
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Patent number: 7738561Abstract: An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.Type: GrantFiled: November 16, 2004Date of Patent: June 15, 2010Assignee: Industrial Technology Research InstituteInventors: Ming-Yen Huang, Tzu-Liang Su, Shih-Hao Wang, Chung-Neng Wang, Tihao Chiang
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Publication number: 20090086819Abstract: An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.Type: ApplicationFiled: December 2, 2008Publication date: April 2, 2009Inventors: Ming-Yen Huang, Tzu-Liang Su, Shih-Hao Wang, Chung-Neng Wang, Tihao Chiang
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Publication number: 20090086828Abstract: An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.Type: ApplicationFiled: December 2, 2008Publication date: April 2, 2009Inventors: Ming-Yen Huang, Tzu-Liang Su, Shih-Hao Wang, Chung-Neng Wang, Tihao Chiang
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Patent number: 7391807Abstract: A method transcodes a compressed multi-layer video bitstream that includes a base layer bitstream and an enhancement layer bitstream. The base and enhancement layers are first partially decoded, and then the partially decoded signals are combined with a motion compensated signal yielding a combined signal. The combined signal is quantized into an output signal according to a quantization parameter, and the output signal is variable length encoded as a single layer bitstream. In a preprocessing step, the enhancement layer can be truncated according to rate control constraint, and the same constraints can also be used during the quantization.Type: GrantFiled: April 24, 2002Date of Patent: June 24, 2008Assignee: Mitsubishi Electric Research Laboratories, Inc.Inventors: Yao-Chung Lin, Chung-Neng Wang, Tihao Chiang, Anthony Vetro, Huifang Sun
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Patent number: 7372903Abstract: A method and apparatus for selecting a quantizer scale for each object within a frame to optimize the coding rate is disclosed. A quantizer scale is selected for each region or “object” within each frame such that the target bit rate for the frame is achieved while maintaining a uniform visual quality over the entire frame.Type: GrantFiled: September 22, 1999Date of Patent: May 13, 2008Assignee: MediaTek, Inc.Inventors: Hung-Ju Lee, Tihao Chiang
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Publication number: 20080025411Abstract: A prediction module includes a computation control unit and first to sixth processing units. The computation control unit arranges the pixels of a reference block outputted by a frame buffer appropriately according to data decoded by an entropy decoder into first and second pixel signals, and outputs the same to the first to sixth processing units in units of cycles. The processing units are controlled by the computation control unit to respectively complete corresponding computations in a cycle, and to use the computation results as values of first to sixth output signals to be correspondingly outputted in a next cycle. The computation control unit receives the first to sixth output signals, and computes the output signals so as to obtain pixel values of a macroblock to be predicted.Type: ApplicationFiled: January 19, 2007Publication date: January 31, 2008Applicant: NATIONAL CHENG KUNG UNIVERSITYInventors: Chih-Chieh Chen, Chih-Hung Li, Wen-Hsiao Peng, Tihao Chiang
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Publication number: 20070071090Abstract: The disclosure relates to a method for performing context based binary arithmetic coding with a stochastic bit-reshuffling scheme in order to improve MPEG-4 fine granularity scalability (FGS) based bit-plane coding. The method comprises steps of: replacing 8×8 DCT with 4×4 integer transform coefficient in MPEG-4 AVC (Advance Video-Coding); partitioning each transform coefficient into significant bit and refinement bit; setting up significant bit context based on energy distribution within a transform block and spatial correlation in adjacent blocks; using an estimated Laplacian distribution to derive coding probability for the refinement bit; and using the context across bit-planes to partition each significant bit-plane for saving side information bit.Type: ApplicationFiled: June 21, 2005Publication date: March 29, 2007Inventors: Wen-Hsiao Peng, Tihao Chiang, Hsueh-Ming Hang
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Patent number: 7072394Abstract: A robust fine granularity scalability video encoding includes a base layer encoder and an enhancement layer encoder in which motion compensated difference images are generated by comparing an original image to predicted images at base layer and enhancement layer with motion compensation. Based on leaky and partial predictions, a high quality reference image is constructed at the enhancement layer to improve temporal prediction. In the construction of the high quality reference image, one parameter ? controls the number of bitplanes of the enhancement layer difference coefficients used and another parameter ? controls the amount of predictive leak. A spatial scalability module allows the processed pictures at the base layer and the enhancement layer to have identical or different spatial resolutions.Type: GrantFiled: August 27, 2002Date of Patent: July 4, 2006Assignee: National Chiao Tung UniversityInventors: Hsiang-Chun Huang, Chung-Neng Wang, Tihao Chiang, Hsueh-Ming Hang
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Publication number: 20060104366Abstract: An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.Type: ApplicationFiled: November 16, 2004Publication date: May 18, 2006Inventors: Ming-Yen Huang, Tzu-Liang Su, Shih-Hao Wang, Chung-Neng Wang, Tihao Chiang
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Patent number: 7027511Abstract: The present invention proposes a fast motion estimation using N-queen pixel decimation, whereby after a reference block and a block to be processed are selected in a video sequence, an N×N queens pattern is used for pixel decimation to perform block match, thereby obtaining a good enough block difference value. The present invention combines pixel decimation with fast motion estimation for search points reduction to achieve the object of simplifying computational complexity of motion estimation. Therefore, the present invention can sieve out sufficiently representative pixels and will not increase extra computational complexity.Type: GrantFiled: April 9, 2002Date of Patent: April 11, 2006Assignee: National Chiao Tung UniversityInventors: Chung-Neng Wang, Shin-Wei Yang, Chi-Min Liu, Tihao Chiang
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Patent number: 7020201Abstract: A method of motion estimation for video encoding constructs a binary pyramid structure having three binary layers. A state update module registers and updates repeat occurrence of final motion vectors and a static-state checking module determines if the method is in a static mode or a normal mode based on the repeat occurrence. In a normal mode, the first binary layer is searched within a ±3 pixel refinement window to determine a first level motion vector. In the second binary layer, a search range is computed based on six motion vector candidates. By checking every point within in the search range, a second binary layer search generates a second level motion vector. Finally, a third binary layer search within a ±2 pixel refinement window generates a final motion vector according to the second level motion vector. In a static mode, a fine tuning module performs search within a ±1 pixel refinement window and generates a final motion vector.Type: GrantFiled: November 20, 2002Date of Patent: March 28, 2006Assignee: National Chiao Tung UniversityInventors: Jeng-Hung Luo, Gen-Ming Lee, Chung-Neng Wang, Tihao Chiang
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Publication number: 20050201468Abstract: The present invention provides a method and apparatus for interframe wavelet video coding which comprises Motion Compensated Temporal Filtering and Discrete Wavelet Transform Coding to obtain: 1. compressed quantification error and scalability on temporal analysis and spatial analysis, and 2. scalability on Motion Information (MI) data so that the performance of wavelet video coding on low bitrate can be improved. A method for partitioned coding on MI is proposed: 1. to partitioned coding a motion vector according to the spatial block, the temporal frame, or the numeric precision; 2. to partition motion vectors to a plurality of layers, and, when the video bitstream changes, only the required MI is put into the final bitstream. Accordingly, the performance of wavelet video compression on low bitrate is greatly improved while the compression rate on high bitrate is only a little lower.Type: ApplicationFiled: March 11, 2004Publication date: September 15, 2005Inventors: Sam Tsai, Hsueh-Ming Hang, Chia-Yang Tsai, Tihao Chiang
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Publication number: 20050195896Abstract: The present invention relates to an architecture for stack robust fine granularity scalability (SRFGS), more particularly, SRFGS providing simultaneously temporal scalability and SNR scalability. SRFGS first simplifies the RFGS temporal prediction architecture and then generalizes the prediction concept as the following: the quantization error of the previous layer can be inter-predicted by the reconstructed image in the previous time instance of the same layer. With this concept, the RFGS architecture can be extended to multiple layers that forming a stack to improve the temporal prediction efficiency. SRFGS can be optimized at several operating points to fit the requirements of various applications while the fine granularity and error robustness of RFGS are still remained. The experiment results show that SRFGS can improve the performance of RFGS by 0.4 to 3.0 dB in PSNR.Type: ApplicationFiled: March 8, 2004Publication date: September 8, 2005Inventors: Hsiang-Chun Huang, Chung-Neng Wang, Tihao Chiang, Hsuch-Ming Hang
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Patent number: 6850564Abstract: An apparatus and method for dynamically varying the frame rate of an image sequence is disclosed. In one embodiment, the image sequence is encoded and stored at different frame rates (e.g., 30, 25, 20 fps and so on). Alternatively, only the motion information, e.g., motion vectors, for the other frame rates are stored.Type: GrantFiled: August 31, 1998Date of Patent: February 1, 2005Assignee: Sarnoff CorporationInventors: Sassan Pejhan, Ya-Qin Zhang, Tihao Chiang
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Patent number: 6754241Abstract: A PC-type computer has a system bus (e.g., a PCI bus) configured with a main CPU board, a statistical multiplexing (stat-mux) board, and a plurality of video/audio encoder boards, each configured to receive and compress a corresponding video/audio stream. The stat-mux board performs statistical multiplexing on the different compressed bitstreams to transmit multiple bitstreams over individual shared communication channels. Although each of the boards is configured to the system bus, each encoder board has a digital signal processor (DSP) with a synchronized serial interface (SSI) output port that is directly connected to an SSI input port on a DSP on the stat-mux board (which, in one embodiment, has four such DSPs each with six such SSI input ports). As such, (up to 24) compressed video/audio bitstreams generated on the various encoder boards can be transmitted directly to the stat-mux board without having to go through the system bus.Type: GrantFiled: January 5, 2000Date of Patent: June 22, 2004Assignee: Sarnoff CorporationInventors: Ravi Krishnamurthy, Sriram Sethuraman, Xiaobing Lee, Tihao Chiang
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Publication number: 20040095998Abstract: A method of motion estimation for video encoding constructs a binary pyramid structure having three binary layers. A state update module registers and updates repeat occurrence of final motion vectors and a static-state checking module determines if the method is in a static mode or a normal mode based on the repeat occurrence. In a normal mode, the first binary layer is searched within a ±3 pixel refinement window to determine a first level motion vector. In the second binary layer, a search range is computed based on six motion vector candidates. By checking every point within in the search range, a second binary layer search generates a second level motion vector. Finally, a third binary layer search within a ±2 pixel refinement window generates a final motion vector according to the second level motion vector. In a static mode, a fine tuning module performs search within a ±1 pixel refinement window and generates a final motion vector.Type: ApplicationFiled: November 20, 2002Publication date: May 20, 2004Inventors: Jeng-Hung Luo, Gen-Ming Lee, Chung-Neng Wang, Tihao Chiang