Abstract : The objective of this thesis is to develop an object-based coding framework built upon a family of wavelet coding techniques for a variety of arbitrarily shaped visual object scalable coding applications. Two kinds of arbitrarily shaped visual object scalable coding techniques are investigated in this thesis. One is object-based scalable wavelet still image coding; another is object-based scalable wavelet video coding.

The first part of this thesis studies advanced wavelet transform techniques for scalable still image object coding. In order to adapt to the content of a given signal and obtain more flexible adaptive representation, two advanced wavelet transform techniques, wavelet packet transform and directional wavelet transform, are developed for object-based image coding. Extensive experiments demonstrate that the new wavelet image coding systems perform comparable to or better than state-of-the-art in image compression while possessing some attractive features such as object-based coding functionality and high coding scalability.

The second part of this thesis investigates various components of object-based scalable wavelet video coding. A generalized 3-D object-based directional threading, which unifies the concepts of temporal motion threading and spatial directional threading, is seamlessly incorporated into 3-D shape-adaptive directional wavelet transform to exploit the spatio-temporal correlation inside the 3-D video object. To improve the computational efficiency of multi-resolution motion estimation (MRME) in shift-invariant wavelet domain, two fast MRME algorithms are proposed for wavelet-based scalable video coding. As demonstrated in the experiments, the proposed 3-D object-based wavelet video coding techniques consistently outperform MPEG-4 and other waveletbased schemes for coding arbitrarily shaped video object, while providing full spatio-temporal-quality scalability with non-redundant 3-D subband decomposition.

BIBTEX entry :
@THESIS{2008_liu_phdthesis,
author = {Yu Liu},
title = {Object-Based Scalable Wavelet Image and Video Coding},
school = {The Chinese University of Hong Kong},
year = {2008},
month = {July},
pages = {1-173}
}

Abstract : As a new technology of protecting the copyright under opening network environment, digital watermarking technology has very wide application prospects in commercial video broadcasting, the pay service of digital media of Internet, hierarchical visiting of data, tracing and detecting of data, authentication of e-commerce and so on. This thesis mainly studies digital video watermarking algorithms for copyright protection of digital video products.

With the development of MPEG-4, this standard is very attractive for a large range of applications. Frame-based approach has been migrating to object-based approach. Therefore, object watermarking schemes are needed in the MPEG-4 environment. In this thesis, several novel digital video watermarking algorithms are proposed to adapt to the new situation of current digital video watermarking field.

For the new object-based video compression standard MPEG-4, a object-based digital video watermarking algorithm is proposed. Based on shape adaptive discrete wavelet transform (SA-DWT) and human visual system (HVS), a watermarking embedding method for arbitrarily shaped object using the principle of the weighting mean of wavelet block and a blind object watermarking detection method using the theory of detection and estimate are proposed. According to the basic principle of proposed object watermarking, an image object watermarking scheme is presented; then on the basis of the image object watermarking scheme, a video object watermarking scheme is presented. Experimental results demonstrate that the proposed object watermarking scheme is perceptual invisible and robust against many attacks.

In order to be suitable for the frame-based video compression standard (such as MPEG-2), this thesis applies the principle of the object-based watermarking algorithm to the frame-based watermarking algorithm. A frame-based video watermarking algorithm which extends SA-DWT from arbitrarily shaped region to rectangle region is first presented. Then, for MPEG-2 compressed video stream, this thesis applies the weighting mean of wavelet block to the one of DCT block and proposes a video watermarking scheme for MPEG-2 video stream which adopts digital cosine transform (DCT).

BIBTEX entry :
@THESIS{2002_liu_masterthesis,
author = {Yu Liu},
title = {Research on Algorithms for Digital Video Watermarking},
school = {Dalian University of Technology},
year = {2002},
month = {March},
pages = {1-50}
}

Abstract :This paper proposes a unified loop filter for video coding, which suppresses the quantization noise optimally and improves the objective and subjective qualities of the reconstructed picture simultaneously. The proposed filter unifies nonlinear enhancement filter and linear restoration filter within the classical optimization framework of least mean square error (LMSE). To adapt to locally diverse quantization error characteristics, classification-based strategy is employed to design unified loop filters with different characteristics, which further improves the capability of picture restoration. Experimental results show that the proposed filter achieves superior objective coding gain and better visual quality improvement around edges and textures, compared with H.264/AVC High Profile.

BIBTEX entry :
@ARTICLE{2010_liu_tcsvt,
author = {Yu Liu},
title = {Unified Loop Filter for Video Compression},
journal = {Accepted by IEEE Transactions on Circuits and Systems for Video Technology},
year = {2010}
}

Abstract :This paper presents a 3-D shape-adaptive directional wavelet coding technique for object-based scalable video coding. This technique includes 3-D object-based directional threading and extensions of weighted adaptive lifting scheme. The 3-D object-based directional threading, which unifies the concept of temporal motion threading and 2-D spatial directional threading, provides the opportunities to align a series of video object planes to form a 3-D video object and exploit the spatio-temporal correlation inside the 3-D video object. The weighted adaptive lifting scheme, which is extended from 2-D frame-based image coding to 3-D object-based video coding, is employed to decompose the 3-D video object into a 3-D multi-spatio-temporal resolution video object pyramid for object-based scalable video coding. Experimental results show that the proposed 3-D shape-adaptive directional wavelet coding technique consistently outperforms MPEG-4 and other wavelet-based schemes for coding arbitrarily shaped video objects.

BIBTEX entry :
@ARTICLE{2008_liu_tcsvt,
author = {Yu Liu and King Ngi Ngan and Feng Wu},
title = {3-D Shape-Adaptive Directional Wavelet Transform for Object-Based Scalable Video Coding},
journal = {IEEE Transactions on Circuits and Systems for Video Technology},
year = {2008},
volume = {18},
pages = {888-899},
number = {7},
month = {July}
}

Abstract : In this paper, a new weighted adaptive lifting (WAL)-based wavelet transform is presented. The proposed WAL approach is designed to solve the problems existing in the previous adaptive directional lifting (ADL) approach, such as mismatch between the predict and update steps, interpolation favoring only horizontal or vertical direction, and invariant interpolation filter coefficients for all images. The main contribution of the proposed approach consists of two parts: one is the improved weighted lifting, which maintains the consistency between the predict and update steps as far as possible and preserves the perfect reconstruction at the same time; another is the directional adaptive interpolation, which improves the orientation property of the interpolated image and adapts to statistical property of each image. Experimental results show that the proposed WAL-based wavelet transform for image coding outperforms the conventional lifting-based wavelet transform up to 3.06 dB in PSNR and significant improvement in subjective quality is also observed. Compared with the ADL-based wavelet transform, up to 1.22 dB improvement in PSNR is reported.

BIBTEX entry :
@ARTICLE{2008_liu_tip,
author = {Yu Liu and King Ngi Ngan},
title = {Weighted Adaptive Lifting-based Wavelet Transform for Image Coding},
journal = {IEEE Transactions on Image Processing},
year = {2008},
volume = {17},
pages = {500-511},
number = {4},
month = {April}
}

Abstract : This paper extends the lifting-based motion threading (MTh) technique from the frame-based coding to the object-based coding, attracted by the unique advantages of the object-based coding that do not exist in other coding schemes. The boundary effects, which exist in spatial and temporal wavelet transforms due to the manner of object-based coding, are well suppressed by 3-D shape-adaptive discrete wavelet transform (3D SA-DWT) via the lifting implementation in a unified framework. Based on the proposed object-based MTh technique, a 3-D object-based scalable wavelet video coder is developed. Experimental results show that the proposed coder achieves good performance compared with the existing object-based coders and provides the scalability functionality at the same time.

BIBTEX entry :
@ARTICLE{2007_liu_tcsvt,
author = {Yu Liu and Feng Wu and King Ngi Ngan},
title = {3-D object-based scalable wavelet video coding with boundary effect suppression},
journal = {IEEE Transactions on Circuits and System for Video Technology},
year = {2007},
volume = {17},
pages = {639-644},
number = {5},
month = {May}
}

Abstract : Motion estimation and compensation in wavelet domain have received much attention recently. To overcome the inefficiency of motion estimation in critically sampled wavelet domain, the low-band-shift (LBS) method and the completeto-overcomplete discrete wavelet transform (CODWT) method are proposed for motion estimation in shift-invariant wavelet domain. However, a major disadvantage of these methods is the computational complexity. Although the CODWT method has reduced the computational complexity by skipping the inverse wavelet transform and making the direct link between the critically sampled subbands and the shift-invariant subbands, the full search algorithm (FSA) increases it. In this paper, we proposed two fast multiresolution motion estimation algorithms in shift-invariant wavelet domain: one is the wavelet matching error characteristic based partial distortion search (WMEC-PDS) algorithm, which improves computational efficiency of conventional partial distortion search algorithms while keeping the same estimate accuracy as the FSA; another is the anisotropic double cross search (ADCS) algorithm using multiresolution-spatiotemporal context, which provides a significantly computational load reduction while only introducing negligible distortion compared with the FSA. Due to the multiresolution nature, both the proposed approaches can be applied to wavelet-based scalable video coding. Experimental results show the superiority of the proposed fast motion estimation algorithms against other fast algorithms in terms of speed-up and quality.

BIBTEX entry :
@ARTICLE{2007_liu_spic,
author = {Yu Liu and King Ngi Ngan},
title = {Fast Multiresolution Motion Estimation Algorithms for Wavelet-based Scalable Video Coding},
journal = {Signal Processing: Image Communication},
year = {2007},
volume = {22},
pages = {448-465},
number = {5},
month = {June}
}

Abstract : In this paper, an object-based embedded image coding algorithm based on context classification and quadtree ordering in wavelet packet domain (OB-CCAQO) is proposed. To match up well with the quadtree-based embedded coder, a new cost function for the best basis selection is adopted in SA-DWPT (shape adaptive discrete wavelet packet transform). The significance probability of wavelet coefficient is estimated by convoluting a 9x9 FIR filter matrix kernel with the significance states of neighboring coefficients, and then a context classifier based on Lloyd-Max algorithm is used to categorize the wavelet coefficients with the same or similar significance probability into several contexts. The significance state of wavelet coefficient with respect to a given threshold is encoded using adaptive arithmetic coder based on the classified context. In addition, combined with the structure of the best wavelet packet basis, a complete quadtree representation of wavelet packet coefficients is established to explore the ordering procedure of embedded object-based image coding. Experimental results show that the proposed object-based embedded image coder offers coding performance superior to the popular object-based coders and is also comparable to or better than the state-of-art embedded image coder when applied in the framed-based image coding.

BIBTEX entry :
@ARTICLE{2006_liu_spic,
author = {Yu Liu and King Ngi Ngan},
title = {Embedded wavelet packet object-based image coding based on context classification and quadtree ordering},
journal = {Signal Processing: Image Communication},
year = {2006},
volume = {21},
pages = {143-155},
number = {2},
month = {Feb.}
}

Abstract : The growth of new image technologies has created a need for techniques that can be used for copyright protection of digital images and video. One approach for copyright protection is to introduce an invisible signal, known as a digital watermark, into an image or video sequence. With the development of MPEG-4, frame-based approach has been migrating to object-based approach. Therefore, object-based watermarking schemes are needed. In this article, we propose a novel blind object watermarking scheme for images and video using shape adaptive-discrete wavelet transform (SA-DWT). To make the watermark robust and perceptual invisible, we embed it in the weighting mean of the wavelet blocks using the quantisation visual model based on the human visual system. Watermark detection is accomplished without the original, unwatermarked object by using statistical detection technique. Experimental results demonstrate that the proposed watermarking scheme is perceptual invisible and robust against many attacks such as lossy image/video compression (e.g. JPEG, JPEG2000 and MPEG-4), scaling, adding noise, filtering, D/A and A/D conversion, etc.

BIBTEX entry :
@ARTICLE{2004_kong_ivc,
author = {Xiangwei Kong and Yu Liu and Huajian Liu and Deli Yang},
title = {Object Watermarks for Digital Images and Video},
journal = {Image and Vision Computing},
year = {2004},
volume = {22},
pages = {583-595},
number = {8},
month = {Aug.}
}

Abstract : The effects of photoelectricity transform on digital watermark are discussed. An adaptive digital watermark algorithm based on image content is proposed which can be applied to photoelectricity transform. By ICPM (image complexity perception model), the features in different domain of the image are analyzed, the domains added watermarking properly are found, and the statistical distribution of wavelet coefficients in different domains is used to add and retrieve watermarking. Experimental results show that the algorithm is of strong robustness for various attacks.

BIBTEX entry :
@ARTICLE{2001_kong_jol,
author = {Xiangwei Kong, Huajian Liu, Yu Liu},
title = {Impact of Photoelectric Processing on Digital Watermarking},
journal = {Journal of Optoelectronics Laser},
year = {2001},
volume = {12},
pages = {627-630},
number = {6},
month = {Jun.}
}

Abstract :Motion estimation as well as the corresponding motion compensation is a core part of modern video coding standards, which highly improves the compression efficiency. On the other hand, motion information takes considerable portion of compressed bit stream, especially in low bit rate situation. In this paper, an efficient motion vector prediction algorithm is proposed to minimize the bits used for coding the motion information. First, a possible motion vector predictor (MVP) candidate set (CS) including several scaled spatial and temporal predictors is defined. To increase the diversity of predictors, the spatial predictor is adaptively changed based on current distribution of neighboring motion vectors. After that, adaptive template matching technique is applied to remove non-effective predictors from the CS so that the bits used for the MVP index can be significantly reduced. As the final MVP is chosen based on minimum motion vector difference criterion, a guessing strategy is further introduced so that in some situations the bits consumed by signaling the MVP index to the decoder can be totally omitted. The experimental results indicate that the proposed method can achieve an average bit rate reduction of 5.9% compared with the H.264 standard.

BIBTEX entry :
@CONFERENCE{2010_yang_mmsp,
author = {Wen Yang and Oscar Au and Jingjing Dai and Feng Zou and Chao Pang and Yu Liu},
title = {Motion Vector Coding Algorithm Based on Adaptive Template Matching},
booktitle = {Accepted by 2010 IEEE International Workshop on Multimedia Signal Processing (MMSP010)},
address = {Saint-Malo, France},
year = {2010},
month = {October}
}

Abstract :In this paper, we propose a unified loop filter for high-performance video coding, which suppresses the quantization noise optimally and improves the objective and subjective quality of the reconstructed picture simultaneously. The proposed filter unifies nonlinear enhancement filter (for removing blocking and ringing artifacts) and linear restoration filter (for improving coding efficiency) within the classical optimization framework of least mean square error (LMSE). Experimental results show that the proposed unified loop filter achieves on average 11.53% objective coding gain in combination with better visual quality improvement around edges and textures, compared with H.264/AVC High Profile.

BIBTEX entry :
@CONFERENCE{2010_liu_icme,
author = {Yu Liu and Yan Huo},
title = {Unified Loop Filter for High-performance Video Coding},
booktitle = {Special Sessions of 2010 IEEE International Conference on Multimedia & Expo (ICME2010)},
address = {Singapore},
year = {2010},
month = {July}
}

Abstract :Motion Estimation is a core part of modern video coding standards, which highly improves the compression efficiency. On the other hand, motion information takes considerable portion of compressed bit stream, especially in low bit rate situation. In this paper, an efficient motion vector prediction algorithm is proposed to minimize the bits used for coding the motion information. Several spatial and temporal neighboring motion vectors are selected as the motion vector predictor (MVP) candidates. By applying template matching to each block, the near-optimal MVP can be obtained both at the encoder and decoder side, so no predictor index is needed to transmit to the decoder. We also embedded the MVP into current motion estimation process. Furthermore, a correction technique is executed as a remedy when template matching picks out a non-efficient predictor. Simulation results indicate that a bit rate reduction of up to 7.29% over H.264/AVC is achieved by the proposed scheme.

BIBTEX entry :
@CONFERENCE{2010_yang_iscas,
author = {Wen Yang and Oscar Au and Chao Pang and Jingjing Dai and Feng Zou and Yu Liu},
title = {An Efficient Motion Vector Coding Algorithm Based on Adaptive Motion Vector Prediction},
booktitle = {Special Sessions of 2010 IEEE International Symposium on Circuits and Systems (ISCAS2010)},
address = {Paris, France},
year = {2010},
month = {May}
}

Abstract :In most of recent video coding standards based on block-based hybrid coding scheme, especially in the state-of-theart H.264/AVC standard, motion vector information occupies a considerable portion of the whole compressed bitstream. Therefore, the efficient coding of motion vectors has become an essential objective to further reduce the bitrate. In this paper, we propose a novel motion vector coding method based on predictor selection and estimation. First, the optimal motion vector predictor (MVP) is chosen from a predefined predictor candidate set consisting of both spatial predictors and temporal predictors to minimize the number of bits used for encoding motion vector difference (MVD). Then, in order to avoid sending extra bits for informing the decoder which candidate is selected by the encoder, boundarymatching (BM) estimation is applied at the decoder side to find out the optimal predictor. The basic principle of BM estimation is to preserve the spatial continuity of boundaries between currently reconstructed block and its neighbors. Simulation results show that compared to the original H.264/AVC codec, the proposed scheme improves coding efficiency for various video sequences.

BIBTEX entry :
@CONFERENCE{2009_dai_mmsp,
author = {Jingjing Dai and Oscar Au and Wen Yang and Chao Pang and Feng Zou and Yu Liu},
title = {Motion Vector Coding based on Predictor Selection and Boundary-matching Estimation},
booktitle = {Proc. of 2009 IEEE International Workshop on Multimedia Signal Processing (MMSP'09)},
address = {Rio de Janeiro, Brazil},
year = {2009},
month = {October}
}

Abstract :This paper presents a 2-D pipeline-based locally adaptive inter-view-temporal lifting scheme for scalable multiview video coding. Instead of global temporal and inter-view correlation analysis based on the whole picture, the proposed method adopts locally adaptive inter-view-temporal correlation analysis based on the macroblocks. In addition, in order to reduce the memory requirement and computational complexity and remove both of temporal and view boundary effects, a new 2-D pipeline-based lifting scheme is proposed. Experimental results show that the proposed scheme always outperforms the other tested schemes in coding efficiency, while providing several advantages, such as view scalability, pipeline-based processing, and moderate complexity.

BIBTEX entry :
@CONFERENCE{2009_liu_iscas,
author = {Yu Liu and King Ngi Ngan},
title = {Fully Scalable Multiview Wavelet Video Coding},
booktitle = {Proc. of 2009 IEEE International Symposium on Circuits and Systems (ISCAS2009)},
address = {Taipei, Taiwan, R.O.C.},
year = {2009},
month = {May}
}

Abstract :This paper presents a novel 3-D direction aligned wavelet transform for scalable video coding. A new generalized 3-D directional threading technique is seamlessly incorporated into 3-D weighted adaptive lifting (WAL)-based wavelet transform to exploit the spatio-temporal correlation inside the video cube along the 3-D directional trajectory, leading to a new class of algorithm called 3-D direction aligned wavelet transform (DAWT). Experimental results show that the proposed 3-D WAL-based DAWT achieves better coding performance than the conventional 3-D discrete wavelet transform (3-D DWT).

BIBTEX entry :
@CONFERENCE{2008_liu_iscas,
author = {Yu Liu and King Ngi Ngan and Feng Wu},
title = {3-D Direction Aligned Wavelet Transform for Scalable Video Coding},
booktitle = {Proc. of 2008 IEEE International Symposium on Circuits and Systems (ISCAS2008)},
address = {Seattle, USA},
year = {2008},
month = {May}
}

Abstract :In this paper, we propose a new weighted adaptive lifting (WAL)-based wavelet transform that is designed to solve the problems existing in the previous adaptive directional lifting (ADL) approach. The proposed approach uses the weighted function to make sure that the prediction and update stages are consistent, the directional interpolation to improve the orientation property of interpolated image, and adaptive interpolation filter to adjust to statistical property of each image. Experimental results show that the proposedWAL-based wavelet transform for image coding outperforms the conventional lifting-based wavelet transform up to 3.02 dB in PSNR and significant improvement in subjective quality is also observed. Compared with the ADL approach, up to 1.18 dB improvement in PSNR is reported.

BIBTEX entry :
@CONFERENCE{2007_liu_icip,
author = {Yu Liu and King Ngi Ngan},
title = {Weighted adaptive lifting-based wavelet transform},
booktitle = {Proc. of 2007 IEEE International Conference on Image Processing (ICIP2007)},
address = {San Antonio, USA},
year = {2007},
month = {Sept.}
}

Abstract :This paper extends the lifting-based motion threading technique from the frame-based coding to the object-based coding, attracted by the unique advantages of the object-based coding that do not exist in other coding schemes. The boundary effects, which exist in spatial and temporal wavelet transforms due to the manner of object-based coding, are well suppressed by 3D shape adaptive discrete wavelet transform (3D SA-DWT) via the lifting implementation in a unified framework. Based on the proposed object-based motion threading technique, a 3D object-based scalable wavelet video coder is developed. Experimental results show that the proposed coder achieves good performance compared with the existing object-based coders, and provides the scalability functionality at the same time.

BIBTEX entry :
@CONFERENCE{2007_liu_iscas,
author = {Yu Liu and Feng Wu and King Ngi Ngan},
title = {3D Object-Based Scalable Wavelet Video Coding with Boundary Effect Suppression},
booktitle = {Proc. of 2007 IEEE International Symposium on Circuits and Systems (ISCAS2007)},
address = {New Orleans, USA},
year = {2007},
month = {May}
}

Abstract :In this paper, we propose a fast lossless multi-resolution motion estimation algorithm in shift-invariant wavelet domain by using wavelet matching error characteristic based partial distortion elimination (MR-WMEC-PDE). Due to its multi-resolution nature, the proposed approach can be applied to scalable video coding. The proposed algorithm can achieve the same estimate accuracy as full search algorithm (FSA), while needing much less computation requirement than FSA.

BIBTEX entry :
@CONFERENCE{2006_liu_iscas,
author = {Yu Liu and King Ngi Ngan},
title = {Fast Lossless Multi-Resolution Motion Estimation for Scalable Wavelet Video Coding},
booktitle = {Proc. of 2006 IEEE International Symposium on Circuits and Systems (ISCAS2006)},
address = {Island of Kos, Greece},
year = {2006},
month = {May}
}

Abstract :In this paper, we make use of the anisotropic property of the motion field in wavelet domain to develop an anisotropic double cross search algorithm using multiresolution-spatio-temporal context (MR-STC-ADCS) for fast lossy motion estimation in shift-invariant wavelet domain. Experimental results demonstrate the superiority of the proposed fast lossy MR-STC-ADCS algorithm against other fast lossy algorithms in terms of speed-up and visual quality.

BIBTEX entry :
@CONFERENCE{2006_liu_pcs,
author = {Yu Liu and King Ngi Ngan},
title = {Anisotropic Double Cross Search Algorithm using Multiresolution-Spatio-Temporal Context for Fast Lossy In-Band Motion Estimation},
booktitle = {Proc. of 2006 Picture Coding Symposium (PCS2006)},
address = {Beijing, China},
year = {2006},
month = {April}
}

Abstract :This paper presents an embedded wavelet packet image coding algorithm which is based on context classification and quadtree ordering (CCAQO). To match up well with the quadtree-based embedded coder, a new cost function for the best basis selection is adopted in discrete wavelet packet transform (DWPT). In addition, combined with the structure of the best wavelet packet basis, a complete quadtree representation of wavelet packet coefficients is established to explore the ordering procedure of embedded image coding. Since subband correlation is mainly captured by significance coding, our focus is on significance coding. The significance probability of wavelet coefficient is estimated by convoluting a 9$\times$9 FIR filter matrix kernel with the significance states of neighboring coefficients, and then a context classifier based on Lloyd-Max algorithm is used to categorize the wavelet coefficients with the same or similar significance probability into several contexts. The significance state of wavelet coefficient with respect to a given threshold is encoded using adaptive arithmetic coder based on the classified context. Experimental results show that the proposed embedded image coder offers coding performance superior to or comparable to the state-of-the-art image coders.

BIBTEX entry :
@CONFERENCE{2005_liu_vcip,
author = {Yu Liu and King Ngi Ngan},
title = {Embedded Image Coding Based on Context Classification and Quadtree Ordering in Wavelet Packet Domain},
booktitle = {Proc. of SPIE Visual Communications and Image Processing (VCIP2005)},
address = {Beijing, China},
volume = {5960},
pages = {1723-1731},
year = {2005},
month = {July}
}

Abstract :In this paper, we propose an approach to blind watermarking of objects of images and video based on shape adaptive discrete wavelet transform (SA-DWT). Unlike most watermarking methods, the watermark is not embedded by modulating individual wavelet coefficient but by modulating the weighting mean of coefficients in the wavelet blocks. Experimental results demonstrate that the proposed watermarking scheme is perceptual invisible and robust against many attacks such as lossy image/video compression (e.g., JPEG, JPEG2000 and MPEG-4), scaling, adding noise, filtering, D/A and A/D conversion, etc.

BIBTEX entry :
@CONFERENCE{2001_liu_icics,
author = {Yu Liu and Xiangwei Kong and Deli Yang},
title = {A Blind Object Watermarking Scheme Based on SA-DWT},
booktitle = {Proc. of IEEE International Conference on Information, Communications and Signal Processing (ICICS2001)},
address = {Singapore},
year = {2001},
month = {October}
}

Abstract :In this paper, a new adaptive watermarking scheme for uncompressed and compressed video is presented. The proposed method embeds the watermark in DC components by quantizing DC coefficients to reference values, instead of embedding the watermark in AC components. To increase robustness and perceptual invisibility, adaptive quantization control strategy (AQCS) and error compensation strategy (ECS) are introduced. Experimental results demonstrate the proposed watermarking scheme is robust and invisible, and is feasible for real time system implementation.

BIBTEX entry :
@CONFERENCE{2001_kong_pcm,
author = {Xiangwei Kong and Yu Liu and Huajian Liu},
title = {Adaptive Video Watermarking Scheme},
booktitle = {Lecture Notes In Computer Science, Vol. 2195, Proc. of the Second IEEE Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing (PCM2001)},
address = {Beijing, China},
pages ={933-938},
year = {2001},
month = {October}
}

Abstract :A color image adaptive watermarking scheme is proposed. To increase the robustness and perceptual invisibility, a model called ICPM (image complexity and perceptibility model) is proposed to analyze the different sub-blocks' properties. A novel technique is proposed for the watermark casting and retrieval by utilizing the properties of the image itself. Experimental results demonstrate the robustness of the algorithm to many attacks, such as JPEG, JPEG2000 and A/D conversion.

BIBTEX entry :
@CONFERENCE{2001_liu_iscas,
author = {Huajian Liu and Xiangwei Kong and Xiangdong Kong and Yu Liu},
title = {Content-based Color Image Adaptive Watermarking Scheme},
booktitle = {Proc. of 2001 IEEE International Symposium on Circuits and Systems (ISCAS2001)},
address = {Sydney, Australia},
pages ={41-44},
year = {2001},
month = {May}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2010_ngan_patent_jnd,
author = {King Ngi Ngan and Lin Ma and Wai Kuen Cham and Yu Liu},
title = {Method and Apparatus for Video Coding by ABT-based Just Noticeable Difference},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2010},
month = {Mar.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2010_siu_patent_mvp,
author = {Wan-Chi Siu and Yan-Ho Kam and Hoi-Kwok Cheung and and Yu Liu},
title = {Method and Apparatus for Motion Prediction in Video Coding},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_zou_patent_dip,
author = {Feng Zou and Oscar C. Au and and Yu Liu},
title = {Edge-based Adaptive Directional Intra Prediction},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_yang_patent_mvc,
author = {Wen Yang and Oscar C. Au and and Yu Liu},
title = {Method and Apparatus for Motion Vector Coding},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_liu_patent_ulf,
author = {Yu Liu and Yan Huo and Ka Man Cheng},
title = {"Method and Apparatus for Improving Video Quality", U.S. Non-Provisional Patent Application, Patent Pending},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {December}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_chan_patent_psb,
author = {Yui Lam Chan and Chang Hong Fu and Wan-Chi Siu and Wai Lam Hui and Ka Man Cheng and Yu Liu and Yan Huo},
title = {Generation of Synchronized Bidirectional frames and uses thereof},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {Oct.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_po_patent_zoom,
author = {Lai-Man Po and Ka-Man Wong and Kwok-Wai Cheung and Ka-Ho Ng and Yu Liu<},
title = {Method and Apparatus for Zoom Motion Estimation},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {Oct.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_fong_patent_qps,
author = {Chi Keung Fong and Wai Kuen Cham and Ka Man Cheng and Yu Liu},
title = {Method And Apparatus For Adaptive Quantization In Digital Video Coding},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {Oct.}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2009_fong_patent_eob,
author = {Chi Keung Fong and Wai Kuen Cham and Yiu Leung Fong and Yu Liu and Ka Man Cheng},
title = {Method and Device for Context modeling of 4X4 EOB},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2009},
month = {August}
}

Abstract : N/A

BIBTEX entry :
@PATENT{2008_liu_patent_fgn,
author = {Yu Liu and Ka Man Cheng and Yan Huo and Lu Wang},
title = {Method and Apparatus for Modeling Film Grain Noise},
institution = {Hong Kong Applied Science & Technology Research Institute},
year = {2008},
month = {Sept.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_liu_avs_m2668,
author ={Yu Liu and Yan Huo and Ka-Man Cheng},
title = {Further Results of Unified Loop Filter in RM62l Platform},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2668, Video Proposal, AVS 32nd meeting, Guangzhou, China},
year = {2010},
month = {Mar.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_fong_avs_m2666,
author = {C.K. Fong and W.K. Cham and Yu Liu and Carmen K.M. Cheng},
title = {Adaptive Block-size Transform for AVS2.0},
institution = {Joint Proposal by The Chinese University of Hong Kong and Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2666, Video Proposal, AVS 32nd meeting, Guangzhou, China},
year = {2010},
month = {Mar.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_yang_vceg_am16,
author ={Wen Yang and Oscar C. Au and Jingjing Dai and Feng Zou and Xing Wen and Yu Liu},
title = {Efficient Motion Vector Coding Algorithms Based on Adaptive Template Matching Techniques},
institution = {Joint Proposal by Hong Kong University of Science and Technology and Hong Kong Applied Science & Technology Research Institute},
organization = {VCEG AM16, Video Proposal, 39th VCEG Meeting, Kyoto, Japan},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_zou_vceg_am15,
author ={Feng Zou and Oscar C. Au and Wen Yang and Xing Wen and Yu Liu},
title = {Edge-based Adaptive Directional Intra Prediction (EADIP)},
institution = {Joint Proposal by Hong Kong University of Science and Technology and Hong Kong Applied Science & Technology Research Institute},
organization = {VCEG AM15, Video Proposal, 39th VCEG Meeting, Kyoto, Japan},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_kam_mpeg_m17181,
author = {Yan-Ho Kam and Wan-Chi Siu and Yui-Lam Chan and Wai-Lam Hui and Chang-Hong Fu and Yu Liu and Ka-Man Cheng and Yan Huo},
title = {Variable Block Size Skip Mode and New Partition Modes for Inter-prediction},
institution = {Joint Proposal by Hong Kong Polytechnic University and Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG M17181, Video Proposal, 91st MPEG Meeting, Kyoto, Japan},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_siu_mpeg_m17180,
author = {Wan-Chi Siu and Yan-Ho Kam and Yu Liu and Ka-Man Cheng and Yan Huo},
title = {Advanced Direct Mode for Bi-directionally Predictive Block Coding},
institution = {Joint Proposal by Hong Kong Polytechnic University and Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG M17180, Video Proposal, 91st MPEG Meeting, Kyoto, Japan},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_liu_mpeg_m17171,
author = {Yu Liu and Yan Huo and Ka-Man Cheng},
title = {Unified Loop Filter for Video Coding},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG M17171, Video Proposal, 91st MPEG Meeting, Kyoto, Japan},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2010_po_mpeg_m17163,
author = {Lai-Man Po and Ka-Man Wong and Ka-Ho Ng and Kwok-Wai Cheung and Chi-Wang Ting and Yu Liu and Ka-Man Cheng and Yan Huo},
title = {Motion Compensated Prediction by Subsampled Block Matching for Zoom Motion Contents},
institution = {Joint Proposal by City University of Hong Kong and Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG M17163, Video Proposal, 91st MPEG Meeting, Kyoto, Japan},
year = {2010},
month = {Jan.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_cham_avs_m2657,
author = {W.K. Cham and C.K. Fong and Yu Liu and Carmen K.M. Cheng},
title = {An investigation of Order-16 Transform in M2606 ABT},
institution = {Joint Proposal by The Chinese University of Hong Kong and Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2657, Video Proposal, AVS 31st meeting, Beijing, China},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_yang_avs_m2650,
author ={Wen Yang and Oscar C. Au and Jingjing Dai and Feng Zou and Xingyu Zhang and Yu Liu and Lu Fang and Xing Wen and Chao Pang and Yi Yang},
title = {Efficient Motion Vector Coding Algorithm},
institution = {Joint Proposal by Hong Kong University of Science and Technology and Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2650, Video Proposal, AVS 31st meeting, Beijing, China},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_zou_avs_m2649,
author ={Feng Zou and Oscar C. Au and Wen Yang and Yu Liu},
title = {Edge-based Adaptive Directional Intra Prediction},
institution = {Joint Proposal by Hong Kong University of Science and Technology and Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2649, Video Proposal, AVS 31st meeting, Beijing, China},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_fong_avs_m2647,
author ={C.K. Fong and W.K. Cham and K.N. Ngan and Yu Liu and Carmen K.M. Cheng},
title = {Adaptive Block-size Transform towards AVS 2.0},
institution = {Joint Proposal by The Chinese University of Hong Kong and Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2647, Video Proposal, AVS 31st meeting, Beijing, China},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_liu_avs_m2644,
author ={Yu Liu and Yan Huo and Carmen K.M. Cheng},
title = {Unified Loop Filter for AVS2.0},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2644, Video Proposal, AVS 31st meeting, Beijing, China},
year = {2009},
month = {Dec.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_chan_mpeg_m16914,
author = {Yui-Lam Chan and Changhong Fu and Wan-Chi Siu and Wai-Lam Hui and Yan-Ho Kam and Yu Liu and Ka-Man Cheng, and Yan Huo},
title = {PSB-frame for MVC},
institution = {Joint Proposal by Hong Kong Polytechnic University and Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG M16914, Video Proposal, 90th MPEG Meeting, Xian, China},
year = {2009},
month = {Oct.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_po_mpeg_m16891,
author = {Lai-Man Po and Ka-Man Wong and Ka-Ho Ng and Kwok-Wai Cheung and Yu Liu and Ka-Man Cheng and Yan Huo},
title = {Block-Matching Translation and Zoom Motion Compensated Prediction},
institution = {Joint Proposal by City University of Hong Kong and Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG M16891, Video Proposal, 90th MPEG Meeting, Xian, China},
year = {2009},
month = {Oct.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_dai_mpeg_m16862,
author = {Jingjing Dai and Wen Yang and Oscar C. Au and Feng Zou and Xing Wen and Haitao Yang and Yu Liu and Wan-Chi Siu and Kam Yan-Ho},
title = {An efficient motion vector coding algorithm based on adaptive motion vector prediction},
institution = {Joint Proposal by Hong Kong University of Science and Technology, Hong Kong Applied Science & Technology Research Institute and Hong Kong Polytechnic University},
organization = {MPEG M16862, Video Proposal, 90th MPEG Meeting, Xian, China},
year = {2009},
month = {Oct.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_cham_avs_m2610,
author = {W.K. Cham and C.K. Fong and Y.L. Fong and K.N. Ngan and Yu Liu and Carmen K.M. Cheng},
title = {Adaptive Block-size Transform towards AVS 2.0},
institution = {Joint Proposal by The Chinese University of Hong Kong and Hong Kong Applied Science & Technology Research Institute},
organization = {AVS m2610, Video Proposal, AVS 30th meeting, Wuxi, China},
year = {2009},
month = {Sept.}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_cheng_mpeg_m16718,
author = {Carmen Cheng and Yan Huo and Yu Liu},
title = {3DV results on Dog sequence},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG m16718, Contributions to the Exploration Experiments, MPEG 89th meeting, London, UK},
year = {2009},
month = {June}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_cheng_mpeg_m16326,
author = {Carmen Cheng and Yan Huo and Yu Liu},
title = {3DV results on Dog sequence},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG m16326, Contributions to the Exploration Experiments, MPEG 88th meeting, Maui, USA},
year = {2009},
month = {April}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_cheng_mpeg_m16047,
author = {Carmen Cheng and Yan Huo and Yu Liu},
title = {3DV EE4 results on Dog sequence},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG m16046, Contributions to the Exploration Experiments, MPEG 87th meeting, Lausanne, Switzerland},
year = {2009},
month = {January}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2009_cheng_mpeg_m16046,
author = {Carmen Cheng and Yan Huo and Yu Liu},
title = {3DV EE3 results on Dog sequence},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {MPEG m16046, Contributions to the Exploration Experiments, MPEG 87th meeting, Lausanne, Switzerland},
year = {2009},
month = {January}
}

Abstract : N/A

BIBTEX entry :
@STANDARD{2008_liu_avs_m2438r1,
author = {Yu Liu and Carmen Cheng and Yan Huo},
title = {Signal-Dependent Auto-Regressive Model-based Film Grain Noise Synthesis},
institution = {Hong Kong Applied Science & Technology Research Institute},
organization = {AVS M2438r1, Video Proposal, 26th AVS Working Group Meeting, Tianjin, China},
year = {2008},
month = {Sept.}
}