In this paper a new adaptive subband thresholding algorithm is introduced for finding the optimize threshold values of the subbands. The search technique is exhaustive, where the distortion level and bit allocation ar...
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ISBN:
(纸本)9781424404681
In this paper a new adaptive subband thresholding algorithm is introduced for finding the optimize threshold values of the subbands. The search technique is exhaustive, where the distortion level and bit allocation are used as the limiting factors. The algorithm is applied in multistage lattice VQ (MLVQ) to enhance the PSNR performance. The MLVQ image coding technique reduces the quantization error of the quantized vectors by "blowing out" the residual quantization errors witha LVQ scale factor. Experimental results for images using the adaptive subband thresholding technique and the MLVQ are shown to be superior to those of JPEG2000 for a set of test images.
This paper aims to present a reconfigurable architecture for a class of digital signal/imageprocessingapplications. The architecture exploits the speed of hardware and the flexibility of Programmable Processors (IT)...
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ISBN:
(纸本)0780370805
This paper aims to present a reconfigurable architecture for a class of digital signal/imageprocessingapplications. The architecture exploits the speed of hardware and the flexibility of Programmable Processors (IT). The proposed architecture consists of a Processor Control Block (PCB) and a Reconfigurable processing Block (RPB). The PCB consists of a Processor and Memory Modules. The RPB consists of a number of Reconfigurable FPGAs that are used for executing image/digital signalprocessing functions. The PCB is responsible for fetching and decoding signal/imageprocessing functions (SPIs) like SMOOTH , FIR, EDGE_DETECTION , DCT , IDCT etc. After decoding, the PCB;sends e control data and information to the RPB. Upon receiving the control signals and data, the RPB starts executing an SPI. After the execution of an SPI, control is returned back to the PCB for fetching and decoding of the next SPI. Execution of SPIs by this architecture is analogous to the execution of instructions by conventional General Purpose Processors. During the execution of an SPI by RPB, PCB can be involved in executing other work. The overhead involved in reconfiguring the FPGA has been reduced to zero by overlapped reconfiguration operations. There is also an incredible saving in hardware as the same FPGA is used as different processing blocks. In addition, the architecture is scalable because new modules can be added or existing modules can be modified very easily by adding or changing the configuration bitstream for the SPIs.
Medical imageprocessing plays an important role in supporting the diagnosis of various diseases. Brain magnetic resonance imaging (MRI) image is widely used to support the decisions from doctors who will decide if th...
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ISBN:
(纸本)9781509023776
Medical imageprocessing plays an important role in supporting the diagnosis of various diseases. Brain magnetic resonance imaging (MRI) image is widely used to support the decisions from doctors who will decide if there are any issues in a brain. The essence of the MRI is segmentation which is the basic for damaged area selection, quantitative measurement and 3-dimensional reconstruction. In order to effectively identify the located objects, this paper introduces a segmentation algorithm using global entropy minimization. This algorithm uses two times segmentation approach based on the cluster area image model to overcome the negative influences of shifted segmentation. From the experiments, the proposed algorithm get the best performance and keeps the highest accuracy. For the similarity, the proposed algorithm has almost the same performance of least biased fuzzy clustering (LBFC) which have 10% outperformance on fuzzy C-means algorithm (FCMA).
Segmentation is a key step in vision applications. In this study a novel method is proposed to achieve robust and low-cost polyhedral segmentation for 3-D range image. A two-dimensional gradient histogram space is gen...
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ISBN:
(纸本)0780362985
Segmentation is a key step in vision applications. In this study a novel method is proposed to achieve robust and low-cost polyhedral segmentation for 3-D range image. A two-dimensional gradient histogram space is generated based on gradients along directions of x and y coordinates. The problem of surface segmentation becomes a problem of points clustering in the feature space. A four-neighborhood iterative expanding algorithm is proposed for region grouping according to the gradient feature space. For noise and geometrical distortion regions, a merge process is applied to the initial segmentation results. The selection of parameters used in this segmentation approach is also discussed. The experimental results show that the proposed algorithm provides a new approach of range image segmentation with the characteristics of low computational complexity and less sensitivity to noise.
Adaptive Directional Lifting (ADL) has been successfully implemented in image compression and denoising due to the feature of simple structure and flexible directional selectivity. However, image denoising by means of...
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ISBN:
(纸本)9781424442966
Adaptive Directional Lifting (ADL) has been successfully implemented in image compression and denoising due to the feature of simple structure and flexible directional selectivity. However, image denoising by means of ADL introduces many visual artifacts caused by Gibbs phenomena due to the lack of translation invariance. In this paper, we propose a translation invariant directional lifting (TI-DL) by employing the cycle-spinning based technique to reduce artifacts in denoising results. Moreover, the inefficiency and high computational complexity of the orientation estimation technique in ADL strongly influences the performance. In order to achieve better denoising results, in this paper, 2-D Gabor filters are adopted for orientation estimation to achieve better orientation estimation results with lower complexity. Experimental results demonstrate that the proposed method achieves state-of-art denoising performance in terms of both objective (PSNR) and subjective (SSIM) evaluation.
In this paper, we address the problem of generating a superresolution image based on a dictionary of low-and highresolution exemplars from a single input image in wavelet domain with a overall enhancement procedure. M...
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ISBN:
(纸本)9781509041176
In this paper, we address the problem of generating a superresolution image based on a dictionary of low-and highresolution exemplars from a single input image in wavelet domain with a overall enhancement procedure. Most methods extract different kinds of features in low-resolution image and high-resolution images to establish the mapping relation. But in this paper, we implement wavelet-transform to extract the same kind of feature to make the mapping more reasonable. Meanwhile we implement local Lipschitz regularity constraint and structure-keeping constraint to preserve the local singularity and edge in our method. Compared with current state-of-art methods on standard images, our method obtains both visual and PSNR improvement.
Recently, Narozny et al [1] proposed a new viewpoint in variable high-rate transform coding. They showed that the problem of finding the optimal 1-D linear block transform for a coding system employing entropy-constra...
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ISBN:
(纸本)9781424407286
Recently, Narozny et al [1] proposed a new viewpoint in variable high-rate transform coding. They showed that the problem of finding the optimal 1-D linear block transform for a coding system employing entropy-constrained uniform quantization may be viewed as a modified independent component analysis (ICA) problem. By adopting this new viewpoint, two new ICA-based algorithms, called GCGsup and ICAorth, were then derived for computing respectively the optimal linear transform and the optimal orthogonal transform. In this paper, we show that the transforms returned by GCGsup and ICAorth can achieve bettervisual image quality (better preservation of lines and contours) than the KLT and 2-D Discrete Cosine Transform (DCT) when applied to the compression of well-known grayscale images.
We have established a novel control system for combining the parallel execution of deterministic and non-deterministic medical imaging applications on a single platform, sharing the same constrained resources. The con...
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ISBN:
(纸本)9781424456536
We have established a novel control system for combining the parallel execution of deterministic and non-deterministic medical imaging applications on a single platform, sharing the same constrained resources. The control system aims at avoiding resource overload and ensuring throughput and latency of critical applications, by means of accurate resource-usage prediction. Our approach is based on modeling the required computation tasks, by employing a combination of weighted moving-average filtering and scenario-based Markov chains to predict the execution. Experimental validation on medical imageprocessing shows an accuracy of 97%. As a result, the latency variation within non-deterministic analysis applications is reduced by 70% by adaptively splitting/merging of tasks. Furthermore, the parallel execution of a deterministic live-viewing application features constant throughput and latency by dynamically switching between quality modes. Interestingly, our solution can successfully be reused for alternative applications with several parallel streams, like in surveillance.
The removal of noise caused by environmental factors in microscopic imaging studies has become an important research topic in the field of medical imaging. In the medical imaging stage made with any digital microscopy...
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ISBN:
(纸本)9781665450928
The removal of noise caused by environmental factors in microscopic imaging studies has become an important research topic in the field of medical imaging. In the medical imaging stage made with any digital microscopy method (Confocal, Fluorescence, etc.), undesirable noises are added to the image obtained due to factors stemming from excessive or low illumination, high or low temperature, or electronic circuit equipment. The most basic noise model formed due to these environmental factors mentioned is the Gaussian normal distribution or a characteristic function close to this distribution. It is widely known that spatial filters (mean, median, Gaussian smoothing) are applied to eliminate Gaussian noise in digital imageprocessing. However, undesirable results may occur in the images obtained when spatial filters are used to remove the noise in the images. In particular, because high frequencies are suppressed in images where spatial filters are applied, details are lost in the final image, and a blurred image is obtained. For this reason, four different convolutional neural network-based models are used for noise removal and to improve the PSNR values in this study. As a result, the modified U-Net improved the PSNR values for different noise levels as follows: +6.23, +7.88 and +10.52 dB
With the development of society, the image size and resolution are gradually increasing. At the same time, the fast imageprocessing is required. The K-SVD algorithm is an iterative method that alternates between spar...
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ISBN:
(纸本)9781509013456
With the development of society, the image size and resolution are gradually increasing. At the same time, the fast imageprocessing is required. The K-SVD algorithm is an iterative method that alternates between sparse coding and updating the overcomplete dictionary. It is a very simple and highly effective method for the signal of sparse representation. However, the K-SVD algorithm is a computationally intensive algorithm. The traditional computing model will take a lot of time to complete the calculation. As the next generation computing model, Spark not only has a strong computing power, but also has a memory-based fast processing capacity. In order to process image denoising efficiently, this paper proposes a implementation of distributed parallel optimization of K-SVD algorithm (K-SVD-P) on Spark. The results showed that K-SVDP not only has a good speed-up ratio, but also retains the image texture and other details.
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