Ultrasound imaging has features like non-invasive nature, real time image formation capacity and relatively low cost, which makes this diagnostic tool attractive and hence has become an important imaging modality in m...
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ISBN:
(纸本)9781479978496
Ultrasound imaging has features like non-invasive nature, real time image formation capacity and relatively low cost, which makes this diagnostic tool attractive and hence has become an important imaging modality in medical diagnoses. However the usefulness of this imaging is degraded by the presence of speckle noise. Hence, speckle suppression in ultrasound images is essential for improving the image quality. In this paper, a novel hybrid method is proposed for enhancing the visual quality of medical ultrasound images. To preserve edges, a nonlinear filter is used in the pre-processing stage. Further the pre-processed image is denoised in wavelet domain using bivariate shrinkage. The quality of the despeckled images is assessed using objective quality assessment metrics such as Peak signal to Noise Ratio (PSNR), Root Mean Squared Error (RMSE) and Edge Preservation Index (EPI). The quantitative results indicate that the proposed method yields better performance than the existing methods.
In multidimensional signalprocessing, such as image and video processing, superresolution (SR) imaging is a classical problem. Over the past 25 years, academia and industry have been interested in reconstructing high...
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In multidimensional signalprocessing, such as image and video processing, superresolution (SR) imaging is a classical problem. Over the past 25 years, academia and industry have been interested in reconstructing high-resolution (HR) images from their low-resolution (LR) counterparts. We review the development of SR technology in this tutorial article based on the evolution of key insights associated with the prior knowledge or regularization method from analytical representations to data-driven deep models. The coevolution of SR with other technical fields, such as autoregressive modeling, sparse coding, and deep learning, will be highlighted in both model-based and learning-based approaches. Model-based SR includes geometry-driven, sparsity-based, and gradient-profile priors;learning-based SR covers three types of neural network (NN) architectures, namely residual networks (ResNet), generative adversarial networks (GANs), and pretrained models (PTMs). Both model-based and learning-based SR are united by highlighting their limitations from the perspective of model-data mismatch. Our new perspective allows us to maintain a healthy skepticism about current practice and advocate for a hybrid approach that combines the strengths of model-based and learning-based SR. We will also discuss several open challenges, including arbitrary-ratio, reference-based, and domain-specific SR.
The extraction of relevant lip features is of continuing interest in the speech domain. Using end-to-end feature extraction can produce good results, but at the cast of the results being difficult for humans to compre...
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ISBN:
(纸本)9781538692769
The extraction of relevant lip features is of continuing interest in the speech domain. Using end-to-end feature extraction can produce good results, but at the cast of the results being difficult for humans to comprehend and relate to. We present a new, lightweight feature extraction approach, motivated by glimpse based psychological research into facial barcodes. This allows for 3D geometric features to be produced using Gabor based image patches. This new approach can successfully extract lip features with a minimum of processing, with parameters that can be quickly adapted and used for detailed analysis, and with preliminary results showing successful feature extraction from a range of different speakers. These features can be generated online without the need for trained models, and are also robust and can recover from errors, making them suitable for real world speech analysis.
The paper describes the implementation and use of recently developed DFT and DCT based discrete Sinc-interpolation algorithms for the Direct Fourier Method of reconstructing images from projections. DFT based discrete...
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ISBN:
(纸本)953184061X
The paper describes the implementation and use of recently developed DFT and DCT based discrete Sinc-interpolation algorithms for the Direct Fourier Method of reconstructing images from projections. DFT based discrete sinc-interpolation is the only completely reversible discrete interpolation technique. DCT based discrete sinc-interpolation algorithm implements the same interpolation kernel that that of the DFT based method and allows to avoid its boundary affect artifacts. It is also computationally more efficient. Two modifications of the DCT based interpolation for tomographic reconstruction are suggested: interpolation by global zooming of 1-D DFT spectra Of projections and interpolation with variable zooming factor along the angle coordinate. The latter allows to substantially reduce the computational complexity without compromising interpolation accuracy. Results of comparative numerical simulation of suggested algorithms show a good image reconstruction quality with a reduced level of artifacts.
We introduce and describe MAT2DSP, a MATLAB toolbox, whose function is to estimate the computational load of algorithms specified in the form of a MATLAB program (or programs). This toolbox is aimed at providing resea...
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ISBN:
(纸本)0780336941
We introduce and describe MAT2DSP, a MATLAB toolbox, whose function is to estimate the computational load of algorithms specified in the form of a MATLAB program (or programs). This toolbox is aimed at providing researches developing advanced signal and imageprocessing algorithms, a quick and convenient way of estimating the implementation requirements of their algorithm on a variety of processors. MAT2DSP analyzes the user program and generates reports on its computational requirements.
In this paper, we propose a kind of pre-processing method which can be applied to the depth learning method for the characteristics of aerial image. This method combines the color and spatial information to do the qui...
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ISBN:
(纸本)9781538621592
In this paper, we propose a kind of pre-processing method which can be applied to the depth learning method for the characteristics of aerial image. This method combines the color and spatial information to do the quick background filtering. In addition to increase execution speed, but also to reduce the rate of false positives
Traditional magnetic flux leakage signal need be processed through each channels in magnetic array data, that increased processing system complexity. This paper proposed a processing system for unsaturated magnetic im...
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In the present era of mechanization, image segmentation has brought revolutionary changes in the field of imageprocessing. There are many image segmentation methods in use but most of the prevalent techniques are not...
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ISBN:
(纸本)9781479915941;9781479915958
In the present era of mechanization, image segmentation has brought revolutionary changes in the field of imageprocessing. There are many image segmentation methods in use but most of the prevalent techniques are not very efficient. In our current work, a method is proposed to segment images using multi-threaded programming and k-means clustering. Parts of images are used as a thread and k-means clustering is used to segment them on every thread. An efficient image segmentation technique using the multi-threaded program is done in this paper. These results are compared with segmentation results without multi-threading. The obtained results are very much encouraging.
Learning visual semantic embedding for image-text matching has achieved high success by using triplet loss to pull positive image-text pairs which share similar semantic meaning and to push negative image-text pairs w...
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Learning visual semantic embedding for image-text matching has achieved high success by using triplet loss to pull positive image-text pairs which share similar semantic meaning and to push negative image-text pairs which share different semantic meaning. Without modeling constraints from image-image or text-text pairs, the generated visual semantic embedding inevitably faces the problem of semantic misalignments among similar images or among similar texts. To solve this problem, we present a contrastive visual semantic embedding framework, named ConVSE, which achieves intra-modal semantic alignment by contrastive learning from augmented image-image (or text-text) pairs and achieves inter-modal semantic alignment by applying hardest-negative-enhanced triplet loss on image-text pairs. To the best of our knowledge, we are the first to find that contrastive learning benefits visual semantic embedding. Extensive experiments on large-scale MSCOCO and Flickr30 K datasets verify the effectiveness of our proposed ConVSE by outperforming visual semantic embedding-based methods and achieving new state-of-the-art.
This paper presents a no-reference (NR) quality assessment method for color images contaminated with additive Gaussian white noise (AGWN). The proposed metric operates on the test image and the scaled down version of ...
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ISBN:
(纸本)9781479961207
This paper presents a no-reference (NR) quality assessment method for color images contaminated with additive Gaussian white noise (AGWN). The proposed metric operates on the test image and the scaled down version of the test image. Standard deviations for each of the RGB components for the test image and its scaled down version are computed. The standard deviation ratios of the scaled down version image to the original test image are weighted summed to obtain the quality score for noise. The performance of the proposed metric is compared with existing full-reference (FR) and NR metrics on LIVE database. Pearson correlation coefficient (CC), mean absolute error (MAE) and root mean square error (RMSE) are used to evaluate the performance of the proposed metric. A CC score of 0.9785 shows that the proposed metric has high correlation with the subjective scores for the LIVE database.
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