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Tele-presence and tele-immersion systems are growing to be more realistic these years. However, few show practical experiences in Internet wide tele-immersion, especially in acceptable end-to-end delay. We present a framework for multi-party tele-immersion applications that allow remote collaborative 3D interactions. This framework performs real-time stereo modeling based on the bumblebee cameras...
Iterative image reconstruction for positron emission tomography (PET) can improve image quality by using spatial regularization that penalizes image intensity difference between neighboring pixels. The most commonly used quadratic penalty often over-smoothes edges and small objects in reconstructed images. Non-quadratic penalties can preserve edges but may introduce piece-wise constant blocky artifacts...
Patient motion degrades image quality in medical imaging. Gating can reduce motion artifacts by using part of the acquired data, but can increase noise. Motion-compensated image reconstruction (MCIR) utilizes all collected data with motion information to reduce motion artifacts and noise. Interactions between Poisson log-likelihood and quadratic regularizers lead to nonuniform and anisotropic spatial...
Microcalcifications are present in a great number of malignant lesions, being considered as a significant sign of malignancy. However, they are detected in less than 50% of mammograms with carcinomas. Given this scenario, systems to highlight infra-clinic lesions, aiding the specialists to make diagnostics, have been studied. These Computer-aided diagnosis systems have been developed based on parameters...
A new method of reconstructing three-dimensional (3D) tubular structures from cone-beam projections is proposed in this paper. Minimal path method is applied to detect 2D tubular structures in the cone-beam projections. The extracted 2D information are fused to design a weight function over the 3D volume so that minimal path method can be applied again to extract centerlines of 3D tubular structures...
Centerline extraction is widely used in medical image processing. It can benefit applications such as building the connectivity map of neurons from microscopic images as well as examining retina vessels for preventing blindness. Many methods have been developed to extract centerlines from 2-D images. An algorithm based on 2-D rapid tensor voting is proposed in this paper. This method uses the Canny...
We report the implementation of a fully on-chip, lensless, sub-pixel resolving optofluidic microscope (SROFM) based on the super resolution algorithm. The device utilizes microfluidic flow to deliver specimens directly across a complementary metal oxide semiconductor (CMOS) sensor to generate a sequence of low-resolution (LR) projection images, where resolution is limited by the sensor's pixel size...
This work proposes a new methodology for the extraction of Harmonic Phase images in cardiac tagged Magnetic Resonance Imaging. The procedure draws upon the use of the Windowed Fourier Transform, which provides a spatially varying representation of the signal spectra. The spectral peaks of the local Fourier domain are then extracted by a conventional Harmonic Phase recovering technique in such a way...
Knife Edge Scanning Microscopy (KESM) is a high-throughput imaging technique used to obtain large-scale anatomical information (≈1cm3) at sub-micrometer resolution. Data acquisition has been fully automated, however significant post-processing and reconstruction must be done manually. KESM is unique in that illumination and tissue sectioning are performed using a diamond knife. Therefore many of the...
Time sequences of 3D images of cerebral and other vasculature blood flow during surgery and other medical procedures allow enhanced visual feedback. The visual feedback constitutes an enhancement over the existing 2D time series of X-ray projections as it facilitates the detection and observation of pathological abnormalities such as stenoses, aneurysms, and blood clots. An algorithm that outputs...
One of the key MRI methodologies to identify and characterize coronary artery disease is dynamic contrast enhanced myocardial perfusion imaging. Rapid acquisition of images can help in improved diagnosis by accurately measuring temporal dynamics of the injected contrast agent. Another competing requirement is complete coverage of the heart with high spatial resolution to better identify sub-endocardial...
The problem of reconstructing an MR image from limited (and sparsely sampled) k-space data in the presence of a reference image occurs in various applications, including interventional imaging and dynamic contrast-enhanced imaging. This paper addresses the problem using a dictionary composed of three types of basis functions: reference-weighted harmonic functions, wavelets, and pixel/voxel indicator...
Single modality biometric recognition system is often not able to meet the desired system performance requirements. Several studies have shown that multimodal biometric identification systems improve the recognition accuracy and allow performances that are required for many security applications. In this paper, we have developed a multimodal biometric recognition system which combines two modalities:...
In this study, we aim at reconstructing single photon emission computed tomography (SPECT) images using a Bayesian framework to incorporate anatomical information from magnetic resonance (MR) as a priori knowledge about the activity distribution. This is achieved using an anatomically-driven Bowsher prior (BP). Standard BP has the potential to obtain similar results as other state-of-the-art prior...
A new method to estimate the variance of noise from the composite magnitude signal of GRAPPA reconstructed images is presented. Parallel imaging methods allow to increase the acquisition rate via subsampled acquisitions of the k-space. However, the reconstruction process yields to a variance of noise value which is dependent on the position within the image. The proposed method uses information of...
Recent developments in optical coherence tomography (OCT) have enabled wide-field and high-resolution angiographic imaging. However, generation of vascular contrast inherently requires long imaging times. In this work, we demonstrate a reconstruction technique based on sparse and redundant representations over trained dictionaries that can be used to reduce acquisition times and accurately reconstruct...
We explore the development and performance of algorithms for hyperspectral diffuse optical tomography (DOT) in which data from hundreds of wavelengths are collected and used to determine the concentration distribution of chromophores in the medium under investigation. An efficient method is detailed for forming the images using iterative algorithms applied to a linearized Born approximation model...
There has been increasing usage of Multiple Description Coding (MDC) for error concealment in non ideal channels. This paper attempts to conceal the error and reconstruct the lost descriptions by combining MDC and LIoyd-max quantizer. At first original image downsampled to four subimages then by using wavelet transform each subimage is mapped to transform domain then descriptions are quantized by...
In this paper, we propose a method for fast generating a digital hologram using General-Purpose Computation on Graphics Processing Units (GPGPU). This method can reduce the computational time of generating a digital hologram by using the parallel processing with CUDA. And we demonstrate the effectiveness of our algorithm through a variety of experiment.
The connectivity of pore is main factor which affect the permeability of coal seam. In this paper, we perform an experiment on the pore structure in blind coal sample and lean coal sample, a non-destructive inspection equipment “micro CT experimental system” is used to scan coal samples, the least scanning unit resolution of the system is 0.5 μm. Based on the micro-CT images, the 3D digital sample...
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