Quality Images (quality + image)

Distribution by Scientific Domains

Kinds of Quality Images

  • high quality image

  • Selected Abstracts

    Exposure Fusion: A Simple and Practical Alternative to High Dynamic Range Photography

    T. Mertens
    I.4.8 [Image Processing]: Scene Analysis , Photometry, Sensor Fusion Abstract We propose a technique for fusing a bracketed exposure sequence into a high quality image, without converting to High dynamic range (HDR) first. Skipping the physically based HDR assembly step simplifies the acquisition pipeline. This avoids camera response curve calibration and is computationally efficient. It also allows for including flash images in the sequence. Our technique blends multiple exposures, guided by simple quality measures like saturation and contrast. This is done in a multiresolution fashion to account for the brightness variation in the sequence. The resulting image quality is comparable to existing tone mapping operators. [source]

    The Pocket Echocardiograph: Validation and Feasibility

    ECHOCARDIOGRAPHY, Issue 7 2010
    Benjamin C. Culp M.D.
    Background: A new, miniaturized ultrasound device, the pocket echocardiograph (PE), is highly portable and can be carried inside a lab-coat pocket. Studies of this device are limited and have not examined the use by novice echocardiographers. We hypothesize that a novice echocardiographer can use PE to produce interpretable cardiac images, and that both novice and expert echocardiographers can use PE to accurately quantify ejection fraction. Methods: Unselected subjects (n = 40) in an echocardiography laboratory underwent blinded formal transthoracic echocardiography (TTE) and PE (Acuson P10, Siemens, Mountain View, CA, USA). A cardiology fellow with 2 months of echocardiography training acquired PE images. The fellow and an experienced echocardiographer interpreted the PE studies offline in a blinded fashion. To assess adequacy, studies were graded as technically adequate, limited, or inadequate. A visual estimation of ejection fraction was made. Comparisons were made to the formal reported TTE. Results: Subjects were heterogeneous, 43% male; age 64 ± 17 years, and ejection fraction 52.4%± 12.3%. All PE studies were interpretable, and the vast majority of PE and TTE images were considered technically adequate (77.5% and 85% respectively; P = 0.32). Ejection fraction showed a good correlation, bias, and limits of agreement for the fellow's interpretation (r = 0.78, ,5.9%, ±16.6%) with stronger association for the experienced echocardiographer (r = 0.88, ,0.8%, ±11.4%). Conclusion: Novice echocardiographers using the PE can produce adequate quality images. Both expert and novice echocardiographers can use PE to quantify ejection fraction over a broad range of patients. The device's low cost and portability may greatly expand the availability of bedside echocardiography for routine or urgent cardiovascular assessment. (Echocardiography 2010;27:759-764) [source]

    1H and 19F nuclear magnetic resonance microimaging of water and chemical distribution in soil columns

    Myrna J. Simpson
    Abstract Nuclear magnetic resonance (NMR) microimaging is a noninvasive and nondestructive technique that has great potential for the study of soil processes. Hydrogen-1 NMR microimaging techniques were used to examine the distribution of water in four different soil cores. Fluorine-19 NMR microimaging is also used to study the transport of three model contaminants (hexafluorobenzene, sodium fluoride, and trifluralin) in soil columns. The 1H water distribution studies demonstrate that NMR microimaging can provide unique detail regarding the nature and location of water in soils. Image distortion (magnetic susceptibility) was observed for soil samples low in water (20,28% by weight) and that contained an iron content of 0.73 to 0.99%. Highly resolved images were obtained for the organic-rich soil (Croatan sample) and also facilitated the analysis of bound and unbound soil water through varying spin echo times. The contaminant studies with 19F NMR demonstrated that preferential flow processes can be observed in soil cores in as little as 16 h. Studies with hexafluorobenzene produced the highest quality images whereas the definition decreased over time with both trifluralin and sodium fluoride as the compounds penetrated the soil. Nonetheless, both 1H and 19F NMR microimaging techniques demonstrate great promise for studying soil processes. [source]

    Quality control in laparoscopic cholecystectomy: operation notes, video or photo print?

    HPB, Issue 3 2001
    PW Plaisier
    Background In 1995 the concept of a ,critical view of safety' (CVS) in Calot's triangle was introduced to prevent bile duct injury in laparoscopic cholecystectomy. The aim of this study was to determine the most reliable method for recording CVS. Methods Operation notes, video images and photo prints from 50 consecutive elective non-converted laparoscopic cholecystectomies were analysed. Results Operation notes alone did not suffice to record CVS. As an adjunct, video proved superior to photo print with regard to quality. Nevertheless, photo prints were practically and logistically much easier to produce than video. Moreover, when good quality images were achieved, photo print recorded CVS more conclusively than video. Discussion Operation notes, video and photo print are complementary, and the combination records CVS conclusively in nearly every case. [source]

    Review of the UK NEQAS (H) digital morphology pilot scheme for continuing professional development accessed via the internet

    Summary UK NEQAS (H) developed and instigated a pilot scheme for digital morphology, which was accessed by participants over the internet in order to assess the viability of using high quality images as an educational tool for continuing professional development. The pilot scheme was trialled over a 2-year period with eight releases totalling 16 morphology cases. Digital images allowed participating individuals to examine and comment on exactly the same cells and compare their findings with those of other participants, consensus data from traditional glass slide surveys and expert opinion. Feedback from participants on their experience was then relayed back to the development team by UK NEQAS (H) in order to drive the educational format and to ensure that any new scheme would meet the requirements of the users. [source]

    Digital photography: A primer for pathologists

    Roger S. Riley
    Abstract The computer and the digital camera provide a unique means for improving hematology education, research, and patient service. High quality photographic images of gross specimens can be rapidly and conveniently acquired with a high-resolution digital camera, and specialized digital cameras have been developed for photomicroscopy. Digital cameras utilize charge-coupled devices (CCD) or Complementary Metal Oxide Semiconductor (CMOS) image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal. Since digital cameras do not utilize photographic film, images are immediately available for incorporation into web sites or digital publications, printing, transfer to other individuals by email, or other applications. Several excellent digital still cameras are now available for less than $2,500 that capture high quality images comprised of more than 6 megapixels. These images are essentially indistinguishable from conventional film images when viewed on a quality color monitor or printed on a quality color or black and white printer at sizes up to 11×14 inches. Several recent dedicated digital photomicroscopy cameras provide an ultrahigh quality image output of more than 12 megapixels and have low noise circuit designs permitting the direct capture of darkfield and fluorescence images. There are many applications of digital images of pathologic specimens. Since pathology is a visual science, the inclusion of quality digital images into lectures, teaching handouts, and electronic documents is essential. A few institutions have gone beyond the basic application of digital images to developing large electronic hematology atlases, animated, audio-enhanced learning experiences, multidisciplinary Internet conferences, and other innovative applications. Digital images of single microscopic fields (single frame images) are the most widely utilized in hematology education at this time, but single images of many adjacent microscopic fields can be stitched together to prepare "zoomable" panoramas that encompass a large part of a microscope slide and closely simulate observation through a real microscope. With further advances in computer speed and Internet streaming technology, the virtual microscope could easily replace the real microscope in pathology education. Later in this decade, interactive immersive computer experiences may completely revolutionize hematology education and make the conventional lecture and laboratory format obsolete. Patient care is enhanced by the transmission of digital images to other individuals for consultation and education, and by the inclusion of these images in patient care documents. In research laboratories, digital cameras are widely used to document experimental results and to obtain experimental data. J. Clin. Lab. Anal. 18:91,128, 2004. © 2004 Wiley-Liss, Inc. [source]

    A Novel Automated Injection System for Angiography

    The present method of performing manual coronary angiography requires repetitive manipulation of a cumbersome stopcock-manifold system and contrast injection by hand syringe. This study reports a novel mechanical contrast injector with automated manifold that provides finger touch operator-controlled contrast injections. The ACIST Injection System components include a software-controlled syringe injector, a disposable automated manifold without stopcocks, a disposable hand controller, and a touch screen control panel. The ACIST system was evaluated in 50 patients undergoing diagnostic coronary angiography (n = 37) or coronary interventions (n = 13). In all cases, the system was easy to use and provided excellent quality images even with four catheters, as well as imaging during stent positioning with 6Fr guides. This mechanical injector facilitates precision operator-controlled angiographic injections, provides superb high quality coronary images even with very small lumen catheters, and expedites ventriculography during angiographic procedures. (J Interven Cardiol 2001;14:147,152) [source]

    Red blood cells labelling with 99mTc-d,l-HMPAO: an alternative method for specific cases

    F.J. Pérez
    Abstract The effectiveness of the classic methods for red blood cells (RBCs) labelling with 99mTc has been demonstrated in nuclear medicine. However, nuclear physicians have found, in certain circumstances, this diagnostic technique fails and poor quality images are obtained. In this work we report on an alternative method that is of useful in these occasions, for in vitro labelling RBCs with 99mTc-d,l-HMPAO complex. The study shows a high and reproducible labelling efficiency (94.14±0.38), using low amount of tin. The RBCs were isolated from plasma and other interfering blood cells before adding 99mTc-d,l-HMPAO. The tracer was retained and the elution rate from RBCs was low (less than 6% after 120 min). The preclinical results indicate that this new method could be a good alternative to the standard classic methods for specific cases. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    7 Tesla MR imaging of the human eye in vivo

    Kathryn Richdale OD
    Abstract Purpose: To develop a protocol which optimizes contrast, resolution and scan time for three-dimensional (3D) imaging of the human eye in vivo using a 7 Tesla (T) scanner and custom radio frequency (RF) coil. Materials and Methods: Initial testing was conducted to reduce motion and susceptibility artifacts. Three-dimensional FFE and IR-TFE images were obtained with variable flip angles and TI times. T1 measurements were made and numerical simulations were performed to determine the ideal contrast of certain ocular structures. Studies were performed to optimize resolution and signal-to-noise ratio (SNR) with scan times from 20 s to 5 min. Results: Motion and susceptibility artifacts were reduced through careful subject preparation. T1 values of the ocular structures are in line with previous work at 1.5T. A voxel size of 0.15 × 0.25 × 1.0 mm3 was obtained with a scan time of approximately 35 s for both 3D FFE and IR-TFE sequences. Multiple images were registered in 3D to produce final SNRs over 40. Conclusion: Optimization of pulse sequences and avoidance of susceptibility and motion artifacts led to high quality images with spatial resolution and SNR exceeding prior work. Ocular imaging at 7T with a dedicated coil improves the ability to make measurements of the fine structures of the eye. J. Magn. Reson. Imaging 2009;30:924,932. © 2009 Wiley-Liss, Inc. [source]

    In vivo MR imaging of pulmonary arteries of normal and experimental emboli in small animals

    Mathieu Lederlin MD
    Abstract Purpose To demonstrate the feasibility of pulmonary MRA in living rodents. Materials and Methods A three-dimensional (3D) gradient echo sequence was adapted to perform a time-of-flight (TOF) angiography of rat lung. Angiogram with a spatial resolution of 195 × 228 × 228 ,m3 was acquired in around 33 minutes. The method was then applied in animals before and after pulmonary embolism (PE) induction. Section of the proximal right pulmonary artery was measured and compared between the two populations. Results Good quality images were obtained with a contrast-to-noise ratio (CNR) of 9 ± 3 in the proximal part of the pulmonary artery. Cross-section areas of the right main artery are statistically different before (3.45 ± 0.69 mm2) and after induction of PE (4.3 ± 0.86 mm2). Conclusion This noninvasive tool permits angiogram acquisition at around 200 ,m spatial resolution and objective distinction between healthy and embolized arteries. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source]

    Surface Laser Scanning of Fossil Insect Wings

    PALAEONTOLOGY, Issue 1 2004
    Olivier Béthoux
    Primary homologization of wing venation is of crucial importance in taxonomic studies of fossil and recent insects, with implications for large-scale phylogenies. Homologization is usually based on relative relief of veins (with an insect ground plan of alternating concave and convex vein sectors). However, this method has led to divergent interpretations, notably because vein relief can be attenuated in fossil material or because wings were originally flat. In order to interpret better vein relief in fossil insect wings, we tested the application of non-contact laser scanning. This method enables high resolution three-dimensional (3-D) data visualization of a surface, and produces high quality images of fossil insect wings. These images facilitate and improve interpretation of the homologization of wing venation. In addition, because the surface information is digitised in three axes (X, Y, Z), the data may be processed for a wide range of surface characteristics, and may be easily and widely distributed electronically. Finally, this method permits users to reconstruct accurately the fossils and opens the field of biomechanical interpretation using numerical modelling methods. [source]

    CCTV on trial: Matching video images with the defendant in the dock,

    Josh P. Davis
    The experiments reported in this paper investigated simultaneous identity matching of unfamiliar people physically present in person with moving video images typical of that captured by closed circuit television (CCTV). This simulates the decision faced by a jury in court when the identity of somebody caught on CCTV is disputed. Namely, ,is the defendant in the dock the person depicted in video'? In Experiment 1, the videos depicted medium-range views of a number of actor ,culprits'. Experiment 2 used similar quality images taken a year previously, some of which showed the culprits in disguise. Experiment 3 utilised high-quality close-up video images. It was consistently found that in both culprit-present and culprit-absent videos and in optimal conditions, matching the identity of a person in video can be highly susceptible to error. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Three-dimensional, multi-offset ground-penetrating radar imaging of archaeological targets

    Adam D. Booth
    Abstract The efficacy of ground penetrating radar (GPR) methods is inhibited when surveying over a target that is structurally complex and/or hosted within attenuative media. Recent research has documented the ability of certain seismic methods to improve imaging using GPR. For imaging complex targets, three-dimensional acquisition and migration methods are applied. For attenuative sites, signal-to- noise ratio (SNR) may be boosted on acquisition of multi-offset data. We present results from an integrated three-dimensional multi-offset survey over a Romano-British villa at Groundwell Ridge, near Swindon, UK. Data were acquired within a grid of dimension 21,m,×,14,m, using a single-channel PulseEKKO GPR system equipped with common-offset (CO) 450,MHz antennas. To satisfy criteria for three-dimensional migration, the sample density over the grid was 0.05,×,0.05,m2. A smaller grid of three-dimensional multi-offset data was acquired, with fold-of-cover 2200%, targeting a low SNR section of data. The spatial resolution and SNR in the resulting images of the target are greatly improved compared with data acquired using a more conventional survey method. However, this improvement may not be justified by the greatly increased (some 10 times) fieldwork effort required to obtain three-dimensional multi-offset data. We therefore investigate a means of improving the efficiency of three-dimensional GPR surveying by applying a simple trace interpolation method to recover three-dimensional acquisition criteria. This trial suggests that, at this site, three-dimensional data can be simulated from a grid of pseudo-three-dimensional data, sampled at 0.05,×,0.25,m2. In this way, high quality images of an archaeological target can be obtained with minimal increase to survey effort. We hope that, on the basis of this work, three-dimensional and multi-offset acquisitions will be more readily considered for archaeological GPR investigations. Copyright © 2008 John Wiley & Sons, Ltd. [source]