We discuss calibration and removal of "vignetting" (radial falloff) and exposure (gain) variations from sequences of images. Even when the response curve is known, spatially varying ambiguities ...prevent us from recovering the vignetting, exposure, and scene radiances uniquely. However, the vignetting and exposure variations can nonetheless be removed from the images without resolving these ambiguities or the previously known scale and gamma ambiguities. Applications include panoramic image mosaics, photometry for material reconstruction, image-based rendering, and preprocessing for correlation-based vision algorithms.
State of the Art on Neural Rendering Tewari, A.; Fried, O.; Thies, J. ...
Computer graphics forum,
20/May , Letnik:
39, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Efficient rendering of photo‐realistic virtual worlds is a long standing effort of computer graphics. Modern graphics techniques have succeeded in synthesizing photo‐realistic images from ...hand‐crafted scene representations. However, the automatic generation of shape, materials, lighting, and other aspects of scenes remains a challenging problem that, if solved, would make photo‐realistic computer graphics more widely accessible. Concurrently, progress in computer vision and machine learning have given rise to a new approach to image synthesis and editing, namely deep generative models. Neural rendering is a new and rapidly emerging field that combines generative machine learning techniques with physical knowledge from computer graphics, e.g., by the integration of differentiable rendering into network training. With a plethora of applications in computer graphics and vision, neural rendering is poised to become a new area in the graphics community, yet no survey of this emerging field exists. This state‐of‐the‐art report summarizes the recent trends and applications of neural rendering. We focus on approaches that combine classic computer graphics techniques with deep generative models to obtain controllable and photorealistic outputs. Starting with an overview of the underlying computer graphics and machine learning concepts, we discuss critical aspects of neural rendering approaches. Specifically, our emphasis is on the type of control, i.e., how the control is provided, which parts of the pipeline are learned, explicit vs. implicit control, generalization, and stochastic vs. deterministic synthesis. The second half of this state‐of‐the‐art report is focused on the many important use cases for the described algorithms such as novel view synthesis, semantic photo manipulation, facial and body reenactment, relighting, free‐viewpoint video, and the creation of photo‐realistic avatars for virtual and augmented reality telepresence. Finally, we conclude with a discussion of the social implications of such technology and investigate open research problems.
Abstract Introduction Physicians have high rates of suicide and depression. Most state medical boards require disclosure of mental health problems on physician licensing applications, which has been ...theorized to increase stigma about mental health and prevent help-seeking among physicians. Methods We surveyed a convenience sample of female physician-parents on a closed Facebook group. The anonymous 24-question survey asked about mental health history and treatment, perceptions of stigma, opinions about state licensing questions on mental health, and personal experiences with reporting. Results 2106 women responded, representing all 50 states and the District of Columbia. Most respondents were aged 30–59. Almost 50% of women believed that they had met the criteria for mental illness but had not sought treatment. Key reasons for avoiding care included a belief they could manage independently, limited time, fear of reporting to a medical licensing board, and the belief that diagnosis was embarrassing or shameful. Only 6% of physicians with formal diagnosis or treatment of mental illness had disclosed to their state. Conclusions Women physicians report substantial and persistent fear regarding stigma which inhibits both treatment and disclosure. Licensing questions, particularly those asking about a diagnosis or treatment rather than functional impairment may contribute to treatment reluctance.
Abstract Purpose Stress urinary incontinence is a common problem experienced by many women that can have a significant negative impact on the quality of life of those who suffer from the condition ...and potentially those friends and family members whose lives and activities may also be limited. Materials and Methods A comprehensive search of the literature was performed by ECRI Institute. This search included articles published between January 2005 and December 2015 with an updated abstract search conducted through September 2016. When sufficient evidence existed, the body of evidence for a particular treatment was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. (Table 1) Results The American Urological Association and the Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction have formulated an evidence-based guideline focused on the surgical treatment of female stress urinary incontinence in both index and non-index patients. This document is designed to be used in conjunction with the associated treatment algorithm. (Figure 1) Conclusions The surgical options for the treatment of stress urinary incontinence continue to evolve; as such, this guideline and the associated algorithm aim to outline the currently available treatment techniques as well as the data associated with each treatment. Indeed, the Panel recognizes that this guideline will require continued literature review and updating as further knowledge regarding current and future options continues to grow.
Pan-STARRS Photometric and Astrometric Calibration Magnier, Eugene. A.; Schlafly, Edward. F.; Finkbeiner, Douglas P. ...
The Astrophysical journal. Supplement series,
11/2020, Letnik:
251, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract We present the details of the photometric and astrometric calibration of the Pan-STARRS1 3 π Survey. The photometric goals were to reduce the systematic effects introduced by the camera and ...detectors, and to place all of the observations onto a photometric system with consistent zero-points over the entire area surveyed, the ≈30,000 deg 2 north of δ = −30°. Using external comparisons, we demonstrate that the resulting photometric system is consistent across the sky to between 7 and 12.4 mmag depending on the filter. For bright stars, the systematic error floor for individual measurements is ( σ g , σ r , σ i , σ z , σ y ) = (14, 14, 15, 15, 18) mmag. The astrometric calibration compensates for similar systematic effects so that positions, proper motions, and parallaxes are reliable as well. The bright-star systematic error floor for individual astrometric measurements is 16 mas. The Pan-STARRS Data Release 2 (DR2) astrometric system is tied to the Gaia DR1 coordinate frame with a systematic uncertainty of ∼5 mas.
Brown dwarfs--substellar bodies more massive than planets but not massive enough to initiate the sustained hydrogen fusion that powers self-luminous stars--are born hot and slowly cool as they age. ...As they cool below about 2,300 kelvin, liquid or crystalline particles composed of calcium aluminates, silicates and iron condense into atmospheric 'dust', which disappears at still cooler temperatures (around 1,300 kelvin). Models to explain this dust dispersal include both an abrupt sinking of the entire cloud deck into the deep, unobservable atmosphere and breakup of the cloud into scattered patches (as seen on Jupiter and Saturn). However, hitherto observations of brown dwarfs have been limited to globally integrated measurements, which can reveal surface inhomogeneities but cannot unambiguously resolve surface features. Here we report a two-dimensional map of a brown dwarf's surface that allows identification of large-scale bright and dark features, indicative of patchy clouds. Monitoring suggests that the characteristic timescale for the evolution of global weather patterns is approximately one day.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper describes a photometric stereo method designed for surfaces with spatially-varying BRDFs, including surfaces with both varying diffuse and specular properties. Our optimization-based ...method builds on the observation that most objects are composed of a small number of fundamental materials by constraining each pixel to be representable by a combination of at most two such materials. This approach recovers not only the shape but also material BRDFs and weight maps, yielding accurate rerenderings under novel lighting conditions for a wide variety of objects. We demonstrate examples of interactive editing operations made possible by our approach.
Current methods for combining two different images produce visible artifacts when the sources have very different textures and structures. We present a new method for synthesizing a transition region ...between two source images, such that inconsistent color, texture, and structural properties all change gradually from one source to the other. We call this process
image melding
. Our method builds upon a patch-based optimization foundation with three key generalizations: First, we enrich the patch search space with additional geometric and photometric transformations. Second, we integrate image gradients into the patch representation and replace the usual color averaging with a screened Poisson equation solver. And third, we propose a new energy based on mixed
L
2
/L
0
norms for colors and gradients that produces a gradual transition between sources without sacrificing texture sharpness. Together, all three generalizations enable patch-based solutions to a broad class of image melding problems involving inconsistent sources: object cloning, stitching challenging panoramas, hole filling from multiple photos, and image harmonization. In several cases, our unified method outperforms previous state-of-the-art methods specifically designed for those applications.
Introduction
The terminology for female pelvic floor prolapse (POP) should be defined and organized in a clinically-based consensus Report.
Methods
This Report combines the input of members of two ...International Organizations, the International Urogynecological Association (IUGA) and the International Continence Society (ICS), assisted at intervals by external referees. Appropriate core clinical categories and a sub-classification were developed to give a coding to definitions. An extensive process of fourteen rounds of internal and external review was involved to exhaustively examine each definition, with decision-making by collective opinion (consensus).
Results
A Terminology Report for female POP, encompassing over 230 separate definitions, has been developed. It is clinically-based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in female pelvic floor dysfunction and POP. Female-specific imaging (ultrasound, radiology and MRI) and conservative and surgical managements are major additions and appropriate figures have been included to supplement and clarify the text. Emerging concepts and measurements, in use in the literature and offering further research potential, but requiring further validation, have been included as an
appendix
. Interval (5–10 year) review is anticipated to keep the document updated and as widely acceptable as possible.
Conclusion
A consensus-based Terminology Report for female POP has been produced to aid clinical practice and research.
BACKGROUND Reproductive failure is a significant public health concern. Although relatively little is known about factors affecting fertility and early pregnancy loss, a growing body of literature ...suggests that environmental and lifestyle factors play an important role. There is sufficient evidence to hypothesize that diet, particularly its constituent antioxidants, and oxidative stress (OS) may influence the timing and maintenance of a viable pregnancy. We hypothesize that conditions leading to OS in the female affect time-to-pregnancy and early pregnancy loss. METHODS We review the epidemiology of female infertility related to antioxidant defenses and oxidation and examine potential sources of OS from the ovarian germ cell through the stages of human pregnancy and pregnancy complications related to infertility. Articles were identified through a search of the PubMed database. RESULTS Female OS is a likely mediator of conception and threshold levels for OS exist, dependent on anatomic location and stage of preconception. CONCLUSIONS Prospective pregnancy studies with dietary assessment and collection of biological samples prior to conception with endpoints of time-to-pregnancy and early pregnancy loss are needed.
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