When the current block is at the edge of the objects, the prediction accuracy of H.264 intra-frame coding will be decreased. An enhanced intra prediction method is proposed in this paper based on the directional of in...
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ISBN:
(纸本)9780769531199
When the current block is at the edge of the objects, the prediction accuracy of H.264 intra-frame coding will be decreased. An enhanced intra prediction method is proposed in this paper based on the directional of intra prediction and correlation among adjacent pixels in the current block. The proposed algorithm use the pixels calculated already as the reference pixels to predict the rest pixels in the current block, and then dynamically update the prediction mode order to achieve more most_probable_modes. Experimental results show that the proposed scheme is able to achieve a remarkable reduction of bit rate, meanwhile the peak signal-noise ratio (PSNR) is slightly increased compared with the original H.264 reference software.
Distributed video coding is a new paradigm for video compression in opposition over the existing video coding standards like MPEG-x and H.26x families. These codecs make use of motion estimation algorithms, the main p...
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Distributed video coding is a new paradigm for video compression in opposition over the existing video coding standards like MPEG-x and H.26x families. These codecs make use of motion estimation algorithms, the main part of the compression process of the video signal. Hence, the compression process demands a high computational cost and high performance of the encoder. The present work proposes a video compression scheme based on the lossy distributed source coding theory. The proposed compressor encodes the odd frames and the even frames separately using turbo codes and the discrete wavelet transform. The decoding process is performed in a iterative manner and explores the statistical dependency of the video frames of the original sequence. This approach gives a great encoding runtime reduction and allows the implementation at devices with limited computation power and memory. Simulation results show the good performance of the proposed codec in comparison with the state of the art video compression standard H.264/AVC.
A new self-adaptive video watermarking, which is combined the motion characteristics detection with the model of the entropy is proposed. By uniting the human visual masking system (HVS) with the blocking-matching tec...
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ISBN:
(纸本)9780769532783
A new self-adaptive video watermarking, which is combined the motion characteristics detection with the model of the entropy is proposed. By uniting the human visual masking system (HVS) with the blocking-matching techniques we acquire the motion information of every macro-block in video sequence such as the velocity, the motion angle, and the deformation. The motion information is statistic by using the motion entropy. According to the entropy of motion information in each macro-block and the human visual masking system, a set of non-linear formulas have been used to calculate the maximum of the embedding strength of the every block in the video sequence to improve the imperceptibility of the watermarking. The results of imperceptible experiments indicate that the imperceptibility of the video watermarking has been improved by introducing the motion characteristics detection and the model of motion entropy. In the robust experiments the proposed algorithm could resisted the normal video watermarking attracts and has the excellent robustness and security.
An optimized JPEG2000 compression algorithm based on LISP platform was brought forward to meet the critical quality requirement of the international standard of VDR. System architecture of radar image capture and comp...
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ISBN:
(纸本)9781424442041
An optimized JPEG2000 compression algorithm based on LISP platform was brought forward to meet the critical quality requirement of the international standard of VDR. System architecture of radar image capture and compression system is presented first. Two new techniques to handle calculation error and irrational number of normalization factor in LS (9, 7) were explained in detail and the test result of them was shown. Finally, three levels of JPEG2000 algorithm transplantation and optimization based on LISP platform are listed.
To reduce spatial redundancies in intra coding, Intra 4times4 mode provides nine directional prediction modes for every 4times4 block. In this paper, an adaptive intra mode bit skip method is proposed to improve codin...
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To reduce spatial redundancies in intra coding, Intra 4times4 mode provides nine directional prediction modes for every 4times4 block. In this paper, an adaptive intra mode bit skip method is proposed to improve coding efficiency in intra coding. The proposed method improves coding efficiency and reduces encoding complexity. Experimental results show that the average bit-rate reduction of 2.86% and 6.58% are achieved at the medium bitrate and low bitrate, respectively. In addition to that, encoding complexity is saved about 42% at the QP values of 27 and 32.
In this paper, a local watermarking scheme in the ridgelet domain combining image content and JND model is presented Since the ridgelet transform (RT) can efficiently represent image with linear singularities and has ...
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ISBN:
(纸本)9781424441969
In this paper, a local watermarking scheme in the ridgelet domain combining image content and JND model is presented Since the ridgelet transform (RT) can efficiently represent image with linear singularities and has directional sensitivity the image is partitioned into small pieces. And these small pieces are classified into different characteristic categories (S1 with weak texture, S2 with strong texture). To improve the robustness of processing like noise or JPEG compressing attack, the lower and middle frequencies of RT subband are selected and the watermarking strength is adaptively determined by the JND values in RT domain. So it will ensure invisibilities of the watermarks. And eventually the watermarks are embedded in the most important energetic directions of the pieces with Strong texture which are less sensitively to human's vision. Experimental results show that the proposed watermarked scheme is robust to noise, cut, JPEG compressing and other intensive attack.
The upcoming reconfigurable video coding (RVC) standard from MPEG (ISO/IEC SC29WG11) defines a library of coding tools to specify existing or new compressed video formats and decoders. The coding tool library has been...
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The upcoming reconfigurable video coding (RVC) standard from MPEG (ISO/IEC SC29WG11) defines a library of coding tools to specify existing or new compressed video formats and decoders. The coding tool library has been written in a dataflow/actor-oriented language named CAL. Each coding tool can be represented with an extended finite state machine and the dependencies between the tools are described as dataflow graphs. This paper proposes an approach to derive a multiprocessor execution schedule for RVC systems that are comprised of CAL actors. In addition to proposing a scheduling approach for RVC, an extension to the well-known permutation flow shop scheduling problem that enables rapid run-time scheduling of RVC tasks is introduced.
This paper describes the efficient selective encryption scheme for H.264/SVC. The proposed scheme encrypts with three domains in hierarchical layers using different keys: the intra prediction modes, the motion vector ...
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This paper describes the efficient selective encryption scheme for H.264/SVC. The proposed scheme encrypts with three domains in hierarchical layers using different keys: the intra prediction modes, the motion vector difference values and the sign bits of the texture data. The features of the proposed scheme are as follow. The proposed scheme offers 1) the computational efficiency by encrypting domains selectively according to each layer type, 2) the time efficiency through the light-weight encryption, 3) the security through the use of mutually different keys, and 4) the format compliance by utilizing the H.264/SVC structure and method.
Video coding technology has evolved in the past years into a variety of different and complex algorithms. So far the specification of such standard algorithms has been done case by case providing monolithic textual an...
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Video coding technology has evolved in the past years into a variety of different and complex algorithms. So far the specification of such standard algorithms has been done case by case providing monolithic textual and reference SW specifications, but without any attention on commonalities and the possibility of incremental improvements or modifications of such monolithic standards. The MPEG Reconfigurable Video coding (RVC) framework is a new ISO standard, currently under development aiming at providing video codec specifications at the level of library functions instead of monolithic algorithms. The possibility to select a subset of standard coding algorithms to specify a decoder that satisfies application specific constraints is very attractive. However, such possibility to reconfigure codecs requires systematic procedures and tools capable of describing the new bitstream syntaxes of such new codecs. Moreover, it is also necessary to generate the associated parsers which are capable to parse the new bitstreams because they are not available ldquoa priorirdquo in the RVC library. This paper further explains the problem and describes the technologies used to describe new bitstream syntaxes within RVC. In addition, the paper describes the methodology and the tools for the validation of bitstream syntaxes descriptions as well as an example of systematic procedures for the direct synthesis of parsers in the same data flow formalism in which the RVC library component are implemented.
Region of interest (ROI) coding is a mechanism deployed in several image coding systems to enable different degrees of coding priority to specific regions of the image. JPEG2000 standard provides two ROI coding method...
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Region of interest (ROI) coding is a mechanism deployed in several image coding systems to enable different degrees of coding priority to specific regions of the image. JPEG2000 standard provides two ROI coding methods. However, both of them are based in mechanisms that scale the quantized coefficients. This compels to encode the additional bit-planes needed for the scaling, causing a penalization in the overall coding performance, and the ROIs can not be modified without a complete re-encoding of the image. This paper introduces two ROI coding methods that use rate-distortion optimization techniques to prioritize arbitrary ROIs over the rest of the image without penalizing the overall coding performance. Experimental results suggest that the proposed methods achieve a close to optimal accuracy, improving the Implicit ROI coding method in terms of ROI rate distortion performance.
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