This paper proposes an efficient, lossless image coding method using Hadamard transformation blocksize of 8 x 8. Hadamard transformation coefficients, when seen as bit patterns, are positively correlated with each oth...
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This paper proposes an efficient, lossless image coding method using Hadamard transformation blocksize of 8 x 8. Hadamard transformation coefficients, when seen as bit patterns, are positively correlated with each other. This is because each element of the transformation matrix is either plus or minus if the normalization factor is ignored. Utilizing bit pattern relationships, the proposed method achieves compression efficiency comparable to that of the JPEG lossless compression method. In addition, the proposed method can be programmed in progressive coding which results in lossless by transmitting transformation coefficients sequentially from low frequencies to high frequencies. This property, which cannot be attained by the JPEG lossless compression method, is very useful in a variety of applications. (C) 1997 Scripta Technica, Inc.
In this paper, we present JPEG-based scalable image compression algorithms for storage and transmission applications. The JPEG standard for still image compression provides the framework for reconstructing images in d...
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In this paper, we present JPEG-based scalable image compression algorithms for storage and transmission applications. The JPEG standard for still image compression provides the framework for reconstructing images in different sizes and picture qualities. These features are generally referred to as spatial and SNR scalability, respectively, and are extremely important in a variety of applications. A review of the different modes of the JPEG standard followed by the implementation and performance evaluation of the progressive and hierarchical coding modes which provide SNR and spatial scalability, respectively, are detailed. We then present a highperformance technique based on Wavelet filter downsampling for achieving spatial scalability within the framework of the hierarchical mode of the JPEG standard. This technique provides substantial improvement in performance while maintaining the compatibility with existing JPEG decoders.
Deterministic prediction in progressive coding of images is investigated. progressive coding first creates a sequence of resolution layers by beginning with an original image and reducing its resolution several times ...
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Deterministic prediction in progressive coding of images is investigated. progressive coding first creates a sequence of resolution layers by beginning with an original image and reducing its resolution several times by factors of some natural number M. Next, the resultant layers are losslessly encoded. The lowest-resolution layer is encoded first, then each higher resolution image is encoded incrementally upon the previous, until the original image is finally encoded. coding efficiency may be improved if knowledge of the rules which produced the lower-resolution image of each pair is used to deterministically predict pixels of the higher, so they need not be encoded. This problem is addressed: given reduction rules expressing each low-resolution pixel as a function of nearby high-resolution pixels and previously-generated low-resolution pixels, find a complete set of rules, each of which deterministically predicts the value of a high-resolution pixel when certain values are found in nearby low-resolution pixels and previously-coded high-resolution pixels. It is shown that this problem is NP-Complete, then propose a recursive algorithm for solving it in optimal time as a depth-first tree search. The extent of prediction is shown to vary depending on the sequence order in which the pixels are processed;upper bounds on predictability are proven and are demonstrated how to find the optimal order. Reduction rules taking their inputs from an area of pixels larger than M x M are shown to exhibit an interdependence between their input pixels such that certain combinations are impossible;a use of this interdependence in a compound prediction that further enhances predictability is demonastrated. This work serves as a basis for both working software implementation and for future research into unsolved problems, which are identified.
A new distributed queue dual bus (DQDB)-based protocol for the transmission of still images is proposed. The image encoding scheme assumed here is hierarchical encoding. DQDB queue-arbitrated (QA) slots are used for t...
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A new distributed queue dual bus (DQDB)-based protocol for the transmission of still images is proposed. The image encoding scheme assumed here is hierarchical encoding. DQDB queue-arbitrated (QA) slots are used for the transmission of image information. Although the paper focuses on image transmission, the protocol can be used for any other type of traffic whose data is hierarchically organized or level-oriented. The proposed protocol also accommodates the possibility of session cancellation initiated by the image's recipient (destination node). Specifically, we develop a multiple request protocol with two request cancellation schemes, and a new pre-emptive reservation scheme. Finally, an analytical evaluation of our protocol using a processor sharing model is presented, and the average message delay, an important performance measure for this type of system, is obtained.
A novel digital half-toning technique is presented for the efficient transformation of grey scale images into bilevel ones. The bilevel image pixels are divided into classes, which are progressively generated in a par...
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A novel digital half-toning technique is presented for the efficient transformation of grey scale images into bilevel ones. The bilevel image pixels are divided into classes, which are progressively generated in a parallel fashion, utilising a simple criterion. A continuous-tone image can thus be progressively coded and transmitted in bilevel form
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