The paper describes a new technique for still colour image compression. The image compression includes transform of image, quantization and encoding. This paper mainly describes the transform of image and quantization...
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ISBN:
(纸本)0889865477
The paper describes a new technique for still colour image compression. The image compression includes transform of image, quantization and encoding. This paper mainly describes the transform of image and quantization technique. The algorithm is based on decomposition on orthogonal wavelet basis and it includes threshold entropy technique to construct the best tree. Quantization is adaptive, threshold is calculated on the basis of nature of image and type of wavelet is used. This paper also describes the comparison of wavelet transform and wavelet packet tree. The experimental aim is to determine the best method to improve the performance. The results are compared in terms of percentage of zeros;percentage of energy retained and signal to noise ratio for standard natural images as well as line-based images.
In this paper, we propose a novel hierarchical statistical model for imagewavelet coefficients. A simple classification scheme is used to construct a model that captures interscale and intrascale dependencies of wave...
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In this paper, we propose a novel hierarchical statistical model for imagewavelet coefficients. A simple classification scheme is used to construct a model that captures interscale and intrascale dependencies of wavelet coefficients. applications to image denoising are presented. We develop a simple algorithm that outperforms other wavelet denoising schemes that exploit first-order statistics, or inter- or intra- scale dependencies alone.
This paper describes a new wavelet-based approach to the motion estimation problem for digital video. A complex- valued discrete wavelet transform is used to decompose each frame into a subsampled directionally bandpa...
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ISBN:
(纸本)0819422134
This paper describes a new wavelet-based approach to the motion estimation problem for digital video. A complex- valued discrete wavelet transform is used to decompose each frame into a subsampled directionally bandpass filtered hierarchy. The transform is defined so that at each level there is an approximate correspondence between local translation and coefficient phase shift. This relationship is used to estimate motion with each orientation subband. The estimates are combined over all orientations and scales using a coarse-to-fine refinement strategy to produce a fractional-pel accurate motion field with a directional confidence measure. The technique is suitable for video compression schemes and can also be used for stereo vision and image registration.
The vision system of human being is sensitive to local contrast. If the wavelet transform and directional contrast are put together, the effect of image fusion may be better. This paper presents a new multi-focus imag...
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ISBN:
(纸本)0889865833
The vision system of human being is sensitive to local contrast. If the wavelet transform and directional contrast are put together, the effect of image fusion may be better. This paper presents a new multi-focus image fusion scheme based on wavelet contrast after researching the directional contrast. First, the input multi-focus images are decomposed by wavelet transform. Second, the high frequency neighborhood and low frequency neighborhood are ratioed on each disaggrega-tire layer of each image. The high frequency wavelet coefficient which is corresponding to bigger ratio is taken as corresponding wavelet coefficient. The neighborhood relativity of pixel is taken into account and the mistake selection of pixel is reduced. The simulation result shows that this scheme is improved than that in Reference [1].
作者：
Rajmic, PBrno Univ Technol
Fac Elect Engn & Commun Technol Dept Telecommun Brno 61200 Czech Republic
The new method of segmented wavelet transform (SegWT) makes it possible to compute the discrete-time wavelet transform of a signal segment-by-segment. This means that the method could be utilized for wavelet-type proc...
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ISBN:
(纸本)3540312579
The new method of segmented wavelet transform (SegWT) makes it possible to compute the discrete-time wavelet transform of a signal segment-by-segment. This means that the method could be utilized for wavelet-type processing of a signal in "real time", or in case we need to process a long signal (not necessarily in real time), but there is insufficient computational memory capacity for it (for example in the signal processors). Then it is possible to process the signal part-by-part with low memory costs by the new method. The method is suitable also for the speech processing, e.g. denoising the speech signal via thresholding the wavelet coefficients or speech coding. In the paper, the principle of the segmented forward wavelet transform is explained and the algorithm is described in detail.
The current paper proposes a novel scheme for nonblind watermarking of images, making use of discrete wavelet transform (DWT), discrete time Fourier transform (DTFT), as well as singular value decomposition, or SVD. D...
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ISBN:
(纸本)9781509064946
The current paper proposes a novel scheme for nonblind watermarking of images, making use of discrete wavelet transform (DWT), discrete time Fourier transform (DTFT), as well as singular value decomposition, or SVD. During the process of embedding, 1-level DWT is used to decompose the host image into its various frequency sub-bands. After this, the high-frequency sub band receives an application of DTFT. This is followed then by SVD, after which the watermark becomes embedded into the nowtransformed host image's singular matrix. Then, the inverses of 1-level DWT, DTFT and SVD are applied in order to obtain a watermarked final image. This paper evaluates the performance of the proposed method of watermarking against a number of attacks, including sharpening, salt and pepper noise, AWGN, gamma correction, histogram equalisation, flipping and cropping. Results obtained during experiments have found that the scheme as proposed does provide high levels of robustness and imperceptibility against various signalprocessing attacks.
The framework for image coding system based on embedded zerotrees consists three stages: (i) wavelet transform (ii) an embedded zerotree encoding and (iii) adaptive arithmetic encoding. In this framework, the selectio...
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ISBN:
(纸本)0818681837
The framework for image coding system based on embedded zerotrees consists three stages: (i) wavelet transform (ii) an embedded zerotree encoding and (iii) adaptive arithmetic encoding. In this framework, the selection of wavelet filter becomes an important issue. In this paper, we present a modification to the scanning approach in the set partitioning algorithm proposed in [3] to exploit the correlation in a local neighborhood. Two new criteria are proposed for evaluating the performance of wavelets in lossless image compression applications: zero tree count and monotone spectral ordering of subbands produced after wavelet transform in a multiresolution scheme. We evaluate several wavelet filters to test the evaluation criteria and present experimental results to justify the proposed performance criteria.
Future space based imaging systems require increasingly larger aperture sizes to keep pace with the demand for higher spatial resolution for both Earth and Space sciences missions. The cost and weight becomes increasi...
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ISBN:
(纸本)0819436828
Future space based imaging systems require increasingly larger aperture sizes to keep pace with the demand for higher spatial resolution for both Earth and Space sciences missions. The cost and weight becomes increasingly prohibitive for telescopes and instruments with apertures greater than 1 meter. A number of solutions are possible and are under investigation;these include: deployable segmented aperture systems, sparse aperture systems, interferometric imaging systems, computational deconvolution and superresolution techniques. The commonality of these techniques lies in increased reliance on sophisticated computational and information theoretic techniques. We give an overview of the complex optical and imageprocessing techniques required for such systems to become operational.
Region-based video coding schemes employed in MPEG-4 is also promising for still image coding applications where images contain a number of objects that can be encoded at different bit rates, such as compression of me...
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ISBN:
(纸本)0780376633
Region-based video coding schemes employed in MPEG-4 is also promising for still image coding applications where images contain a number of objects that can be encoded at different bit rates, such as compression of medical images for archiving and tranmission. Motivated by this fact, in this paper we investigate multi-region and multi-quality (MRMQ) coding based on zerotree wavelet coders. We present a novel scheme which addresses the region size sensitivity problem in region-based coding. The proposed method outperforms the region of interest (ROI) coding unit of JPEG2000, i.e., it is possible to save 0.3 bits per pixel to attain the same ROI/background rate-distortion performance with the proposed MRMQ coding scheme.
This paper comprehensively overviews image and signalprocessing, including their fundamentals, advanced techniques, and applications. imageprocessing involves analyzing and manipulating digital images, while signal ...
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