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App Store Pick of the Week: XPenseTracker

by admin on Feb.17, 2009, under IT News

When you’re traveling for business, you want to make certain you record all the expenses for which you can be reimbursed. And with XpenseTracker installed on iPhone, you can record those expenses as you incur them. Xpense Tracker provides flexible customization, reporting, and exporting options. It lets you track mileage, set your currency, and use iPhone’s camera to record receipts. There’s even a free lite version available.

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iMovie ’09 “surpasses all previous versions” of the video editing application

by admin on Feb.17, 2009, under IT News

“The number of new features in iMovie ’09 is satisfyingly overwhelming,” revels Jeff Carlson (macworld.com) in his 4- (out of 5) mouse review of iMovie ’09. He commends its improved library management, the implementation of image stabilization, and the new Precision Editor. In fact, Carlson asserts that iMovie ’09 has now surpassed earlier versions of iMovie in both features and performance.

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Pssst. Heard the latest iPhone tips?

by admin on Feb.17, 2009, under IT News

Marc Saltzman (usatoday.com) has. And he’s sharing what he’s learned with all of us. Want to know two ways you can save images on iPhone? How “you can delete unwanted emails en masse rather than deleting one at a time”? Or a way to quickly navigate to your Favorite’s screen using the Home button? Saltzman reveals all on his blog.

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Restoration of Bayer-sampled Image Sequences

by admin on Feb.17, 2009, under IT News

Spatial resolution of digital images are limited due to optical/sensor blurring and sensor site density. In single-chip digital cameras, the resolution is further degraded because such devices use a color filter array to capture only one spectral component at a pixel location. The process of estimating the missing two color values at each pixel location is known as demosaicking. Demosaicking methods usually exploit the correlation among color channels. When there are multiple images, it is possible not only to have better estimates of the missing color values but also to improve the spatial resolution further (using super-resolution reconstruction). In this paper, we propose a multi-frame spatial resolution enhancement algorithm based on the projections onto convex sets technique.

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Example-Based Regularization Deployed to Super-Resolution Reconstruction of a Single Image

by admin on Feb.17, 2009, under IT News

In super-resolution (SR) reconstruction of images, regularization becomes crucial when insufficient number of measured low-resolution images is supplied. Beyond making the problem algebraically well posed, a properly chosen regularization can direct the solution toward a better quality outcome. Even the extreme case—a SR reconstruction from a single measured image—can be made successful with a well-chosen regularization. Much of the progress made in the past two decades on inverse problems in image processing can be attributed to the advances in forming or choosing the way to practice the regularization. A Bayesian point of view interpret this as a way of including the prior distribution of images, which sheds some light on the complications involved. This paper reviews an emerging powerful family of regularization techniques that is drawing attention in recent years—the example-based approach. We describe how examples can and have been used effectively for regularization of inverse problems, reviewing the main contributions along these lines in the literature, and organizing this information into major trends and directions. A description of the state-of-the-art in this field, along with supporting simulation results on the image scale-up problem are given. This paper concludes with an outline of the outstanding challenges this field faces today.

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Optimal Registration Of Aliased Images Using Variable Projection With Applications To Super-Resolution

by admin on Feb.17, 2009, under IT News

Accurate registration of images is the most important and challenging aspect of multiframe image restoration problems such as super-resolution. The accuracy of super-resolution algorithms is quite often limited by the ability to register a set of low-resolution images. The main challenge in registering such images is the presence of aliasing. In this paper, we analyse the problem of jointly registering a set of aliased images and its relationship to super-resolution. We describe a statistically optimal approach to multiframe registration which exploits the concept of variable projections to achieve very efficient algorithms. Finally, we demonstrate how the proposed algorithm offers accurate estimation under various conditions when standard approaches fail to provide sufficient accuracy for super-resolution.

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Super-Resolution in Medical Imaging

by admin on Feb.17, 2009, under IT News

This paper provides an overview on super-resolution (SR) research in medical imaging applications. Many imaging modalities exist. Some provide anatomical information and reveal information about the structure of the human body, and others provide functional information, locations of activity for specific activities and specified tasks. Each imaging system has a characteristic resolution, which is determined based on physical constraints of the system detectors that are in turn tuned to signal-to-noise and timing considerations. A common goal across systems is to increase the resolution, and as much as possible achieve true isotropic 3-D imaging. SR technology can serve to advance this goal. Research on SR in key medical imaging modalities, including MRI, fMRI and PET, has started to emerge in recent years and is reviewed herein. The algorithms used are mostly based on standard SR algorithms. Results demonstrate the potential in introducing SR techniques into practical medical applications.

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Inpainting and Zooming Using Sparse Representations

by admin on Feb.17, 2009, under IT News

Representing the image to be inpainted in an appropriate sparse representation dictionary, and combining elements from Bayesian statistics and modern harmonic analysis, we introduce an expectation maximization (EM) algorithm for image inpainting and interpolation. From a statistical point of view, the inpainting/interpolation can be viewed as an estimation problem with missing data. Toward this goal, we propose the idea of using the EM mechanism in a Bayesian framework, where a sparsity promoting prior penalty is imposed on the reconstructed coefficients. The EM framework gives a principled way to establish formally the idea that missing samples can be recovered/interpolated based on sparse representations. We first introduce an easy and efficient sparse-representation-based iterative algorithm for image inpainting. Additionally, we derive its theoretical convergence properties. Compared to its competitors, this algorithm allows a high degree of flexibility to recover different structural components in the image (piecewise smooth, curvilinear, texture, etc.). We also suggest some guidelines to automatically tune the regularization parameter.

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Application Of Papoulis-Gerchberg Method In Image Super-Resolution and Inpainting

by admin on Feb.17, 2009, under IT News

In this paper, we study the Papoulis–Gerchberg (PG) method and its applications to domains of image restoration such as super-resolution (SR) and inpainting. We show that the method performs well under certain conditions. We then suggest improvements to the method to achieve better SR and inpainting results. The modification applied to the SR process also allows us to apply the method to a larger class of images by doing away with some of the restrictions inherent in the classical PG method. We also present results to demonstrate the performance of the proposed techniques.

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Super-Resolution Reconstruction Algorithm To MODIS Remote Sensing Images

by admin on Feb.17, 2009, under IT News

In this paper, we propose a super-resolution image reconstruction algorithm to moderate-resolution imaging spectroradiometer (MODIS) remote sensing images. This algorithm consists of two parts: registration and reconstruction. In the registration part, a truncated quadratic cost function is used to exclude the outlier pixels, which strongly deviate from the registration model. Accurate photometric and geometric registration parameters can be obtained simultaneously. In the reconstruction part, the L1 norm data fidelity term is chosen to reduce the effects of inevitable registration error, and a Huber prior is used as regularization to preserve sharp edges in the reconstructed image. In this process, the outliers are excluded again to enhance the robustness of the algorithm. The proposed algorithm has been tested using real MODIS band-4 images, which were captured in different dates. The experimental results and comparative analyses verify the effectiveness of this algorithm.

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