The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The swallowing process affects several aspects of one's welfare, as nutrition, hydration, respiration and hearing. Magnetic resonance imaging (MRI) has been a valuable tool to study swallowing, since it is a non-invasive procedure that can dynamically capture the shapes of the tongue and other elements involved in the process. The resolution enhancement of the MRI frames support directly diseases...
In this paper we introduce a new algorithm for reconstruction of low-dose CT images. The approach, called multi-resolution feature fusion (MRFF), combines the textural qualities of conventional filtered-back projection images, with the noise suppression ability of non-quadratic regularized iterative reconstructions, to form a fast image reconstruction with good noise texture properties. Low-dose abdominal...
Time of flight information is used in PET to improve image quality. However, the nature of the improvement and its relationship with the precision of the time of flight measurement remains to be well-characterized, particularly in the framework of iterative reconstruction. In this work, hot-spheres phantoms are imaged, and the list data are then degraded to simulate systems with poorer timing resolution...
The new generation of dedicated cardiac SPECT systems achieve high detection efficiency by focusing onto a small field of view (FOV) that encloses a patient's heart. They also generally use a relatively small number of views for angular sampling. The objective of this study is to use simulations to investigate the relationship between number of views and image quality when iterative reconstruction...
The problem of reconstruction of digital images from their degraded measurements is regarded as a problem of central importance in various fields of engineering and imaging sciences. In such cases, the degradation is typically caused by the resolution limitations of an imaging device in use and/or by measurement noise. In the field of optics and nuclear imaging, the noise is commonly assumed to obey...
This paper proposes the novel robust SRR algorithm that can be effectively applied on the sequence that are corrupted by various noise models and can be applied on the real or standard sequence. First, the proposed SRR algorithm is based on the Geman&McClure norm that used for measuring the difference between the projected estimate of the high quality image and each low high quality image and...
This paper, residual high-frequency boost method is imported into the iteration process of the simulation-correction iteration image reconstruction algorithm, and produces more high-frequency details information for the algorithm, which improves the algorithm's performance. We use Matlab to implement the algorithm and the results indicate that importing the residual high-frequency boost into the image...
A global binarization methods of the passport image based on global iterative threshold and local analysis is put forward in this paper after several binarization algorithms of document image are deeply studied according to the characteristics that passport image documents are obviously affected by the complex image background and the shading grid security-lines. Model of the method is simple, and...
A variational approach to reconstruct superresolution image corrupted by Gaussian and salt-and-pepper noise is studied. Since the salt-and-pepper noise is the outliers in the image, it is reasonable to regularize the data-fitting term by L1-norm. Full variational approach and two-phase approach for the data-fitting term are considered. To preserve the edges in the restored image, total variation norm...
Iterative reconstruction (IR) has recently been proposed to improve multiple aspects of image quality over conventional filtered backprojection (FBP) in X-ray computed tomography (CT). FBP reconstruction and its corresponding reconstruction kernels have been optimized for decades to provide the best possible image quality. IR does not have the notion of reconstruction kernels but uses other mechanisms...
Recent results in SRR (Super Resolution Reconstruction) demonstrate that the fusion of a sequence of low-resolution noisy blurred images can produce a higher-resolution image or sequence. Since noise is always present in practical acquisition systems, almost video enhancement algorithms are developed assuming AWGN model for the corrupting noise. When the underlying video measurements are corrupted...
Mass segmentation plays an important role in many computer-aided diagnosis (CAD) system. It is usually used as the previous step of mass classification. In this paper, we propose one novel scheme for segmentation of breast mass in digitized mammograms, which is based on gradient vector flow (GVF) snake and multi-scale analysis using Gaussian pyramid. In the proposed method, mammogram is decomposed...
Many image video enhancements assume that the noise model of the imaging system is known in advance such as AWGN. However, the real noise model is not known in many practical applications. In this paper, we propose a novel robust video enhancement algorithm using SRR (super-resolution reconstruction) based on the stochastic regularization technique by minimizing a cost function. First, the classical...
Camera sensor network (CSN) is widely used in many new applications. But low quality images or videos obtained by cheap surveillance cameras are a bottleneck for the development of CSN. A new motion-based blind super-resolution algorithm is proposed to improve the resolution of acquired image. In this method, improved projection transformation is adopted to estimate relative motion of the low-resolution...
Traditionally, the concept of super resolution reconstruction (SRR) relates to a process whereby images are obtained with resolutions that are beyond the limiting factors of the uncompensated imaging system. Many such SRR algorithms have been proposed during this decade but almost SRR estimations are based on L1 or L2 statistical norm estimation therefore these SRR algorithms are usually very sensitive...
In general, the classical SRR algorithms are usually based on translational observation model hence these SRR algorithms can be applied only on the sequences that have simple translation motion. In order to cope with real video sequences and complex motion sequences, this paper proposes a general observation model for SRR algorithm, fast affine block-based transform, devoted to the case of nonisometric...
Typically, super resolution reconstruction (SRR) is the process by which additional information is incorporated to enhance a noisy low resolution image hence producing a high resolution image. Although many such SRR algorithms have been proposed, almost SRR estimations are based on L1 or L2 statistical norm estimation hence these SRR algorithms are usually very sensitive to their assumed model of...
The image degradation caused by motion blur, non-ideal sample and noise was producing in the process of Image acquirement. This paper proposed a fast super-resolution image reconstruction algorithm basing on image sequences. On the basis of image registration, registration algorithm used affine transform as geometric transform Model. A sequence of low-resolution images was roughly registered basing...
Acoustic imaging exhibits inherent geometric distortions due to variations in sound speed within the body. Additional distortions are missing surfaces, speckle noise, acoustic shadows and resolution inconsistency. These artifacts depend on the positioning of the transducer relative to the scanned organs, and considerably degrade the images obtained. We propose an efficient algorithm that combines...
In this paper we propose a new method to recover images corrupted with salt and pepper noise. The proposed method uses ordered statistics filtering and soft-decisioning in successive approximations to find the locations and amplitudes of all the impulses. In our method we use soft-decision to generate a mask which is based on histogram distributions in local windows to distinguish impulsive noise...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.