An efficient VLSI architecture for 2-D wavelet image coding withnovel image scan

A folded very large scale integration (VLSI) architecture is presented for the implementation of the two-dimensional discrete wavelet transform, without constraints on the choice of the wavelet-filter bank. The proposed architecture is dedicated to flexible block-oriented image processing, such as adaptive vector quantization used in wavelet image coding. We show that reading the image along a two-dimensional (2-D) pseudo-fractal scan creates a very modular and regular data flow and, therefore, considerably reduces the folding complexity and memory requirements for VLSI implementation. This leads to significant area savings for on-chip storage (up to a factor of two) and reduces the power consumption. Furthermore, data scheduling and memory management remain very simple. The end result is an efficient VLSI implementation with a reduced area cost compared to the conventional approaches, reading the input data line by line     

An efficient dictionary learning algorithm and its application to 3-D medical image denoising

In this paper, we propose an efficient dictionary learning algorithm for sparse representation of given data and suggest a way to apply this algorithm to 3-D medical image denoising. Our learning approach is composed of two main parts: sparse coding and dictionary updating. On the sparse coding stage, an efficient algorithm named multiple clusters pursuit (MCP) is proposed. The MCP first applies a dictionary structuring strategy to cluster the atoms with high coherence together, and then employs a multiple-selection strategy to select several competitive atoms at each iteration. These two strategies can greatly reduce the computation complexity of the MCP and assist it to obtain better sparse solution. On the dictionary updating stage, the alternating optimization that efficiently approximates the singular value decomposition is introduced. Furthermore, in the 3-D medical image denoising application, a joint 3-D operation is proposed for taking the learning capabilities of the presented algorithm to simultaneously capture the correlations within each slice and correlations across the nearby slices, thereby obtaining better denoising results. The experiments on both synthetically generated data and real 3-D medical images demonstrate that the proposed approach has superior performance compared to some well-known methods.     

面向图像处理的可重构协处理器结构研究

在现有可重构协处理器设计实现的基础上,根据图像处理算法的特点,提出了一种改进的可重构协处理器结构IRC.在IRC中,采用了一种基于网格的网络结构与行(列)SIMD的工作模式,使得图像处理算法的执行效率得到提高.在典型的图像处理应用中,IRC能够达到通用处理器的7倍以上的速度.     

Depth-buffer targeting for spatially accurate 3-D visualization of medical images

During interactive image-guided surgery (IIGS), a surgeon uses data from medical images to help guide the surgical procedure. At Vanderbilt University, an IIGS software system called Orion has been developed which is capable of displaying up to four 512 x 512 images and the current surgical position using an active optical tracking system. Orion is capable of displaying data from any tomographic image volume and from any NTSC video image. An additional display module has been implemented to display three-dimensional information as well as the tomographic slices. This provides the surgeon with valuable anatomical information that is not readily obtained from the tomographic slices alone. Before the surgery, a set of rendered images is created, each with a different angular view of the tomographic volume in order to surround the site of surgical interest. The major objectives of the display module are to display the appropriate rendered image from the set, identify the current probe position on the selected image, and provide an indication of distance between the probe and the physical point of the anatomy indicated on the image. This can provide the surgeon with vital information such as distance to blood vessels, tumors, or other critical structures.     

Efficient implementation of accurate geometric transformations for 2-D and 3-D image processing

This paper proposes the use of a polynomial interpolator structure (based on Horner's scheme) which is efficiently realizable in hardware, for high-quality geometric transformation of two- and three-dimensional images. Polynomial-based interpolators such as cubic B-splines and optimal interpolators of shortest support are shown to be exactly implementable in the Horner structure framework. This structure suggests a hardware/software partition which can lead to efficient implementations for multidimensional interpolation.     

FAIR: a hardware architecture for real-time 3-D image registration

Mutual information-based image registration, shown to be effective in registering a range of medical images, is a computationally expensive process, with a typical execution time on the order of minutes on a modern single-processor computer. Accelerated execution of this process promises to enhance efficiency and therefore promote routine use of image registration clinically. This paper presents details of a hardware architecture for real-time three-dimensional (3-D) image registration. Real-time performance can be achieved by setting up a network of processing units, each with three independent memory buses: one each for the two image memories and one for the mutual histogram memory. Memory access parallelization and pipelining, by design, allow each processing unit to be 25 times faster than a processor with the same bus speed, when calculating mutual information using partial volume interpolation. Our architecture provides superior per-processor performance at a lower cost compared to a parallel supercomputer.     

High-performance 3D median filter architecture for medical image despeckling

A high-sample rate 3D median filtering processor architecture is proposed, based on a novel 3D median filtering algorithm, that can reduce the computing complexity in comparison with the traditional bubble sorting algorithm. A 3times3times3 filter processor is implemented in VHDL, and the simulation verifies that the processor can process a 128times128times96 MRI image in 0.03 seconds while running at 50 MHz     

Prostate mechanical imaging: 3-D image composition and feature calculations

We have developed a method and a device entitled prostate mechanical imager (PMI) for the real-time imaging of prostate using a transrectal probe equipped with a pressure sensor array and position tracking sensor. PMI operation is based on measurement of the stress pattern on the rectal wall when the probe is pressed against the prostate. Temporal and spatial changes in the stress pattern provide information on the elastic structure of the gland and allow two-dimensional (2-D) and three-dimensional (3-D) reconstruction of prostate anatomy and assessment of prostate mechanical properties. The data acquired allow the calculation of prostate features such as size, shape, nodularity, consistency/hardness, and mobility. The PMI prototype has been validated in laboratory experiments on prostate phantoms and in a clinical study. The results obtained on model systems and in vivo images from patients prove that PMI has potential to become a diagnostic tool that could largely supplant DRE through its higher sensitivity, quantitative record storage, ease-of-use and inherent low cost.     

数字图像处理在三维轮廓形貌测量中的应用

在阐述移相干涉法测量物体三维轮廓基本原理的基础上，对测得的干涉图像进行预处理，并根据条纹扫描波面位相实时检测的数学模型对处理的图像进行计算和高通滤波后，得到了高精表面粗糙度样块的三维轮廓形貌，很好的解决了表面粗糙度三维测量的问题。     

An open baseband processing architecture for future mobile terminal design [accepted from open call]

This article introduces an open wireless architecture (OWA) mobile terminal design, focusing on the open baseband processing platform, to support different existing and future wireless communication standards through multi-dimensional open baseband processing modules with open interface parameters and baseband management systems. The article describes a multilayer, open architecture platform to maximize system flexibility and minimize terminal power consumption, so as to provide an integrated and converged next-generation wireless and mobile communication terminal system. The OWA platform is fully compatible with the computer architecture, with interface-based rather than transmission-specific system architecture, for complete openness and simplicity.     

An open software-radio architecture supporting advanced 3G+ systems

This paper describes a software-radio architecture developed for providing real-time wide-band radio communication capabilities in a form attractive for advanced 3G systems research. It is currently being used to implement signaling methods and protocols similar, but not limited to, evolving 3G radio standards (e.g. umts, cdma2000). An overview of the hardware system is provided along with example software implementations on both high-perfo-mance DSP systems and conventional microprocessors.     

Imaging and visualization of 3-D cardiac electric activity

Noninvasive imaging of cardiac electric activity is of importance for better understanding of the underlying mechanisms and for aiding clinical diagnosis and intervention of cardiac abnormalities. We propose to image the 3D cardiac bioelectric source distribution from body-surface electrocardiograms. Cardiac electrical sources were modeled by a current dipole distribution throughout the entire myocardium, and estimated by using the Laplacian weighted minimum norm (LWMN) algorithm from body-surface potentials. The estimated inverse solution of the current distribution was further improved by using a recursive weighting strategy for localized sources, such as origins of cardiac arrhythmias. Computer simulations were conducted to test the feasibility of the proposed approach by using a 3D ventricle model embedded in a realistically shaped torso model. The boundary element method was used to solve the forward problem from assumed cardiac sources to the body-surface potentials. Two test dipoles were placed in the left and right ventricles, simulating the early activation associated with ventricular arrhythmias. The LWMN inverse solution showed an equivalent source distribution over both ventricles, with spread areas of activity overlying the positions of the test dipoles. The sharpened inverse image provides well-localized focal sources near the test dipole positions. In summary, the presented computer simulation suggests that the proposed 3D cardiac current source imaging and localization approach appears to be a promising candidate for localizing and imaging sites of origins of cardiac activation     

3-D visualization of deep submicrometer transistor characteristics

This paper presents a method for the, three-dimensional (3-D) visualization of device parameters to help identify potential regions of operation as well as highlighting process interactions. The results of the visualization are color-coded mappings of the device parameters and regions that meet the required specification, both showing three process parameters simultaneously. The mappings can be presented as rotating volumes (cubes) and slice plot. They can be obtained with relative ease using commercially available software, and the approach could easily be integrated into existing simulation software     

2D DWT VLSI architecture for wavelet image processing

A cost-effective VLSI architecture with separate data-paths and their corresponding filter structure is proposed for performing a two-dimensional discrete wavelet transform (2D DWT). Compared with the conventional 2D DWT VLSI architectures, the proposed semi-recursive 2D DWT VLSI architecture has minimum hardware cost, and optimised data-bus utilisation, scheduling control overhead and storage size     

Parallel image processing with the block data parallel architecture

Many digital signal and image processing algorithms can be speeded up by executing them in parallel on multiple processors. The speed of parallel execution is limited by the need for communication and synchronization between processors. In this paper, we present a paradigm for parallel processing that we call the block data flow paradigm (BDFP). The goal of this paradigm is to reduce interprocessor communication and relax the synchronization requirements for such applications. We present the block data parallel architecture which implements this paradigm, and we present methods for mapping algorithms onto this architecture. We illustrate this methodology for several applications including two-dimensional (2-D) digital filters, the 2-D discrete cosine transform, QR decomposition of a matrix and Cholesky factorization of a matrix. We analyze the resulting system performance for these applications with regard to speedup and efficiency as the number of processors increases. Our results demonstrate that the block data parallel architecture is a flexible, high-performance solution for numerous digital signal and image processing algorithms     

An adaptive 3-D discrete cosine transform coder for medical imagecompression

A new three-dimensional (3-D) discrete cosine transform (DCT) coder for medical images is presented. In the proposed method, a segmentation technique based on the local energy magnitude is used to segment subblocks of the image into different energy levels. Then, those subblocks with the same energy level are gathered to form a 3-D cuboid. Finally, 3-D DCT is employed to compress the 3-D cuboid individually. Simulation results show that the reconstructed images achieve a bit rate lower than 0.25 bit per pixel even when the compression ratios are higher than 35. As compared with the results by JPEG and other strategies, it is found that the proposed method achieves better qualities of decoded images     

Model-based optical metrology and visualization of 3-D complex objects

This letter addresses several key issues in the process of model-based optical metrology, including three dimensional (3D) sensing, calibration, registration and fusion of range images, geometric representation, and visualization of reconstructed 3D model by taking into account the shape measurement of 3D complex structures,and some experimental results are presented.     

一种图像监测处理装置

设计了一种薄雾天气环境下的图像监测处理装置,本装置可对采集到的图像进行是否需要去雾的判别,以及对需要去雾的图像进行去雾处理,并最终得到视觉效果优异的图像,同时由于本装置设置了图像存储模块,可对图像信息进行存储管理,进一步优化了系统的处理时效,且具有结构简单、易实现等优点.