Segmentation and classification are important problems with applications in areas like textural analysis and pattern recognition. This paper describes a single-stage approach to solve the image segmentation/classifica...
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ISBN:
(纸本)0819437646
Segmentation and classification are important problems with applications in areas like textural analysis and pattern recognition. This paper describes a single-stage approach to solve the image segmentation/classification problem down to the pixel level, using energy density functions based on the wavelet transform. The energy density functions obtained, called Pseudo Power Signatures, are essentially functions of the scale and orientation, and are obtained using separable approximations to the 2-D wavelet transform. A significant advantage of these representations is that they are invariant to signal magnitude, and spatial location within the object of interest. Further, they lend themselves to fast and simple classification routines. We provide a complete formulation of the signature determination problem for 2-D, and propose an effective, albeit simple, technique based on a tensor singular value analysis, to solve the problem. We present an efficient computational algorithm, and a simulation result reflecting the strengths and limitations of this approach. We next present a detailed analysis of a more sophisticated method based on orthogonal projections to obtain signatures which are better representations of the underlying data.
Recently, image forgery has increased with the widespread of using digital images. At least two different images are used when forged images are generated in image splicing which is an image forgery method. Forged and...
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image fusion combines information from multiple images in a single image to increase the information processing capabilities. Infrared and visible image fusion is finding a lot of applications these days, as it brings...
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ISBN:
(纸本)9781665428644
image fusion combines information from multiple images in a single image to increase the information processing capabilities. Infrared and visible image fusion is finding a lot of applications these days, as it brings complementary information from the source images in one image. The performance of image fusion is affected by noise and artifacts, which tend to creep in during fusion process. Pre-processing of source images is generally done to improve the quality of final fused image. In this paper, a general framework for fusion of infrared and visible image is proposed for investigating role of preprocessing on quality of image fusion. Various arrangements of image enhancement and denoising techniques are used to investigate the role of preprocessing in improving the efficiency of image fusion. The subjective and objective performance evaluations show that joint use of denoising and enhancement improves the performance of infrared and visible image fusion.
We study the decomposition and compression of one-way wave propagation and imaging operators using wavelet transform. We show that the matrix representation of the Kirchhoff imaging operator (Kirchhoff migration opera...
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ISBN:
(纸本)0819425915
We study the decomposition and compression of one-way wave propagation and imaging operators using wavelet transform. We show that the matrix representation of the Kirchhoff imaging operator (Kirchhoff migration operator) in space domain is a dense matrix, while the compressed beamlet-operator matrix which is the wavelet decomposition of the Kirchhoff operator, is a highly sparse matrix. The beamlet imaging operator represents the backpropagation of multiscale orthonormal beams (beamlets) at different positions with different angles. The beamlet-operator behaves differently in different wavelet bases. For sharp and short bases, such as the Daubechies 4 (D4), both the interscale and intrascale coupling are strong. On the other hand, the interscale coupling is relatively weak for smooth bases, such as higher-order Daubechies wavelets, Coiflets, and spline wavelets. The images obtained by the compressed beamlet operators are almost identical to the images from a full-aperture Kirchhoff operator. Compared with the conventional limited-aperture Kirchhoff migration (imaging), beamlet migration (imaging) can retain the wide effective aperture of a full-aperture operator, and hence achieve higher resolution and image quality with reduced computational cost. The compression ratio of the imaging operator ranges from a few times to a few hundred times, depending on the frequency, step length and the wavelet basis.
In this paper we introduce a biologically-inspired spatial video filtering chip and discuss its application in wavelet filter banks. Two types of spatial filtering chips have been developed - the thin film analog imag...
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ISBN:
(纸本)0819450804
In this paper we introduce a biologically-inspired spatial video filtering chip and discuss its application in wavelet filter banks. Two types of spatial filtering chips have been developed - the thin film analog image processor (TAIP) and the switched-capacitor analog image processor (SCAIP). Each chip can filter video at high frame rates with Gaussian-like filters having adjustable widths. By linearly combining the outputs of a bank of spatial filter chips we can create a large variety of filters. Effective use of the filtering chips requires two things. First, an assessment of the filters that can be realized within the constraints of the hardware is necessary. Although any function within reasonable constraints can be decomposed into a combination of Gaussian functions, an efficient method to do so is an open problem. We have restricted ourselves to a simpler problem - given a limited number of Gaussian-like functions, what useful classes of filters can be generated? Second, given an image-processing application, a method to organize a choice of filters is needed. We are currently investigating these problems in the context of feature analysis/discrimination, and have found a useful organizing principle in the continuous wavelet transform (CWT).
Gabor filters have been applied in several imageprocessingapplications such as motion analysis, texture discrimination, and image coding, etc. The authors propose a computationally efficient scheme to compute Gabor ...
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ISBN:
(纸本)0780300033
Gabor filters have been applied in several imageprocessingapplications such as motion analysis, texture discrimination, and image coding, etc. The authors propose a computationally efficient scheme to compute Gabor filter responses at multiple resolutions and orientations. An architecture is proposed to compute the responses of these filters in 2-D domain by utilizing the symmetric, antisymmetric, and wavelet characteristics of Gabor filters.
In this paper the Progressive Quadtree wavelet (PQW) codec for lossy image compression is presented. PQW is based on the well known quadtree technique, applied in the wavelet transform domain. The proposed algorithm i...
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ISBN:
(纸本)0780365143
In this paper the Progressive Quadtree wavelet (PQW) codec for lossy image compression is presented. PQW is based on the well known quadtree technique, applied in the wavelet transform domain. The proposed algorithm is designed with the aim of achieving low complexity and reduced memory requirements, keeping in mind applications such as Internet browsing on wireless (e.g. UMTS) channel. Besides its lower complexity, PQW provides the same subjective performance as the popular SPIHT codec while, in terms of the peak signal-to-noise ratio, it exhibits a slight performance loss of about 0.5 dB.
Being able to rapidly detect clouds in satellite imagery is critical in terms of increasing mission efficiency of ground observation satellites. In this work, a new approach has been proposed for cloud detection invol...
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ISBN:
(纸本)9781509064946
Being able to rapidly detect clouds in satellite imagery is critical in terms of increasing mission efficiency of ground observation satellites. In this work, a new approach has been proposed for cloud detection involving the utilisation of lowfrequency Discrete wavelet Transform (DWT) components whose sizes are 1/64 of the original image sizes. In the proposed method, several texture features are calculated from the low-frequency DWT components and the cloud pixels are detected by using a KNearest Neighbors (KNN) classifier. The proposed method has been tested on the Gokturk-2 images. Since the utilization of lowfrequency components leads to a significant loss in detail;the cloud detection performance have decreased to some extent. Nevertheless the obtained results were found to be sufficient for determining the cloudiness rate at a small margin of error, and at approximately 145x increased processing speed.
In this paper, we propose a new method for very low bit-rate video coding that combines H.264/AVC standard and two dimensional discrete wavelet transform. In this method, first a two dimensional wavelet transform is a...
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ISBN:
(纸本)9781424421787
In this paper, we propose a new method for very low bit-rate video coding that combines H.264/AVC standard and two dimensional discrete wavelet transform. In this method, first a two dimensional wavelet transform is applied on each video frame independently to extract the low frequency components for each frame and then the low frequency parts of all frames are coded using H.264/AVC codec. On the other hand, the high frequency parts of the video frames are coded by Run Length Coding algorithm, after applying a threshold to neglect the low value coefficients. Experiments show that our proposed method can achieve better rate-distortion performance at very low bit-rate applications below 16 kbits/s compared to applying H.264/AVC standard directly to all frames. applications of our proposed video coding technique include video telephony, video conferencing, transmitting or receiving video over half-rate traffic channels of GSM networks and so on.
Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several effective compressi...
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ISBN:
(纸本)0819441864
Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several effective compression techniques are applied to compress the resulting audio/video signal in an embedded fashion. This wavelet-based compression algorithm incorporates bit-plane coding, index coding, and Huffman coding. To demonstrate the potential of this audio embedding and audio/video compression algorithm, we embed an audio signal into a video signal and then compress. Results show that overall compression rates of 15:1 can be achieved. The video signal is reconstructed with a median PSNR of nearly 33 dB. Finally, the audio signal is extracted from the compressed audio/video signal without error. The views expressed in this article are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the U. S. Government.
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