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 parameter estimation variance of the Single Point Active Alignment Method (SPAAM) is studied through an experiment where 11 subjects are instructed to create alignments using an Optical See-Through Head Mounted Display (OSTHMD) such that three separate correspondence point distributions are acquired. Modeling the OSTHMD and the subject's dominant eye as a pinhole camera, findings show that a correspondence...
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...
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...
Self-organizing mapping (SOM) is a topology-preserving unsupervised manifold learning technique that maps high-dimensional data into a low-dimensional (often a 2-D) space. SOM has been successfully used as a data-driven approach for model-free functional magnetic resonance imaging (fMRI) data analysis. However, effective clustering or interpretation of the prototypes (weight vectors) in the map is...
Unsharp masking is a popular and simple technique for contrast enhancement and sharpening in digital images. The basic idea in this technique is to emphasize edges and discontinuities in the image by adding the edge information back to the original image. In order to achieve higher contrast level in the processed image, the edge information can be scaled prior addition to the original image. However,...
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...
In fluoroscopic tracking for fractured femur bone fixation, a precise identification of the femoral head provides valuable guidance for positioning the implant instruments such as nails and screws. Noise, occlusions and weak edges challenge the task of automatically segmenting the femoral head. In this paper, a fast and fully automated method to precisely delineate the femoral head in fluoroscopic...
The rapid assessment of how cells respond to pathologic, biological, environmental, and endogenous agents is critical for understanding how such responses may increase genomic instability, disease development and, ultimately, affect quality of life. Recently, we have applied the technique of DNA fiber analysis to increase our understanding of how DNA damaging agents influence DNA replication [1]....
The purpose of this research is to develop automated system for measuring the amount of target fishery resources from images which are taken with underwater camera for fishery investigation in laminaria beds in Nemuro, Japan. The image analysis technology for measuring the amount of target in laminaria beds in Nemuro is needed to develop it. In laminaria beds in Nemuro, there is no efficient method...
Median filtering based on switching is known that one of the most effective algorithms for reducing impulse noise. In this paper, we introduce a Pixel Correlation based Impulse Noise Reduction. The proposed algorithm consists of two main steps, detection and correction. In the first step, noise detection is performed using a scalable detection mask and morphological operation. In the second step,...
Blind deconvolution is the recovery of a sharp version of a blurred image when the blur kernel or point spread function is unknown. Despite of exhaustive research over the last few decades, blind image deconvolution still remains an unsolved problem. In this paper, we present a novel morphology based initial estimation technique of true image for the Iterative Blind Deconvolution (IBD) of linearly...
A novel hybrid and repetitive smoothing-sharpening (HRSST) technique is proposed and its impact is assessed to beneficially enhance sonogram and mammogram images. The technique aims to gain and combine the advantages of both the sharpening process that aims to highlight sudden changes in the image intensity, with the advantages of iterative image smoothing, which is usually applied to remove random...
In this paper, we describe the architecture of a wafer-size CMOS image sensor enabling to enlarge the size of the large-format sensor while maintaining good signal quality. The good signal quality is the key for a low-noise and high-frame rate image sensor. For this purpose, each pixel of our sensor has a programmable voltage amplifier. In addition, the differential readout circuitry on the column...
CMOS image sensors are now used in a variety of camera applications, such as mobile phones, camcorders, and digital still cameras (DSCs). In particular, most digital single-lens reflex (DSLR) cameras and so called “mirror-less” cameras that require a large-format sensor also employ CMOS image sensors due to their lower power consumption and higher readout speed compared to their CCD counterparts.
An ultra-low-noise CMOS image sensor based on an alternative pixel circuit featuring pixel-level voltage amplification is reported. Besides a significant reduction in the contribution of electronic noise generated in column-level circuits, pixel-level voltage amplification achieves sub-electron noise of the pixel-level circuit even without any column-level low-pass filter.
In X-ray imaging, as in other imaging domains, the ultimate sensitivity and signal-to-noise ratio are obtained when each incoming photon is counted - the so-called quantum limit. Present state-of-the-art digital radiography is largely “charge integration” based, which results in a read noise that is composed of the quantum-limited photon shot noise, but also of electronic read noise and excess noise...
Fuzzy logic and fuzzy set theory can be interesting tools for engineers when solving image processing problems. They provide a mathematical model for approximate reasoning, which mimics human reasoning and therefore can be very powerfull. In this paper we review the basic concepts of fuzzy logic and fuzzy set theory, and use these tools for the construction of a filter for random impulse noise removal...
This paper presents a VGA 1/13-inch system-on-chip (SoC), primarily targeted for the consumer camera mobile phone market. In this market low cost, ease of product integration, low module height, and low light image quality are important features. The SoC simplifies integration of the sensor into the final product by providing camera functions such as: automatic exposure control, automatic white balance,...
The paper demonstrates a complete acquisition chain of a 300GHz to 1THz image sensor with on-chip multiplexing in a 0.13μm bulk silicon CMOS technology. The pixel consumes less than 100μW and has a responsivity of 90kV/W at 300GHz and of 1.8kV/W at 1.05THz respectively. High resolution and contrast THz images revealing the inner structure of tree leaves are presented. These results show that multi-frequency...
A self-adaptive canny operator was developed to detect edges of growing citrus images. RGB color images were obtained and linear transformed into R-B chromatic aberration space at first. In R-B space, width of Gaussian filter fast calculated using integral images and the high and low threshold values obtained by OTSU algorithm were extracted to improve automatic edge detection. It is shown that the...
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.