1,504 research outputs found

    Model-based occlusion disentanglement for image-to-image translation

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    Image-to-image translation is affected by entanglement phenomena, which may occur in case of target data encompassing occlusions such as raindrops, dirt, etc. Our unsupervised model-based learning disentangles scene and occlusions, while benefiting from an adversarial pipeline to regress physical parameters of the occlusion model. The experiments demonstrate our method is able to handle varying types of occlusions and generate highly realistic translations, qualitatively and quantitatively outperforming the state-of-the-art on multiple datasets.Comment: ECCV 202

    Bowling for Calibration: An Undemanding Camera Calibration Procedure Using a Sphere

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    Camera calibration is a critical problem in computer vision. This paper presents a new method for extrinsic parameters computation: images of a ball rolling on a flat plane in front of the camera are used to compute roll and pitch angles. The calibration is achieved by an iterative Inverse Perspective Mapping (IPM) process that uses an estimation on ball gradient invariant as a stop condition. The method is quick and as easy to use as throw a ball and is particularly suited to be used to quickly calibrate vision systems in unfriendly environments where a grid is not available. The algorithm correctness is demonstrated and its accuracy is computed using both computer generated and real images

    Pedestrian Validation in Infrared Images by Means of Active Contours and Neural Networks

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    This paper presents two different modules for the validation of human shape presence in far-infrared images. These modules are part of a more complex system aimed at the detection of pedestrians by means of the simultaneous use of two stereo vision systems in both far-infrared and daylight domains. The first module detects the presence of a human shape in a list of areas of attention using active contours to detect the object shape and evaluating the results by means of a neural network. The second validation subsystem directly exploits a neural network for each area of attention in the far-infrared images and produces a list of votes

    Bowling for Calibration: An Undemanding Camera Calibration Procedure Using a Sphere

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    Camera calibration is a critical problem in computer vision. This paper presents a new method for extrinsic parameters computation: images of a ball rolling on a flat plane in front of the camera are used to compute roll and pitch angles. The calibration is achieved by an iterative Inverse Perspective Mapping (IPM) process that uses an estimation on ball gradient invariant as a stop condition. The method is quick and as easy to use as throw a ball and is particularly suited to be used to quickly calibrate vision systems in unfriendly environments where a grid is not available. The algorithm correctness is demonstrated and its accuracy is computed using both computer generated and real images

    Scenario-Driven Search for Pedestrians aimed at Triggering Non-Reversible Systems

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    Abstract-This paper presents the results of an innovative approach to pedestrian detection for automotive applications in which a non-reversible system is used; therefore the aim is to reach a very low false detection rate, ideally zero, by searching for pedestrians in specific areas only. The great advantages of such an approach are that pedestrian recognition is performed on limited image areas-therefore boosting its timing performance- and no assessment on the danger level is finally required before providing the result to either the driver or an on-board computer for automatic manoeuvres. This system has been extensively tested on two prototype vehicles equipped with one laserscanner, one camera, and brakeby-wire technology both in Italy and Korea; this paper describes the extensive tests and shows performance measurements. I

    Environment-Detection-and-Mapping Algorithm for Autonomous Driving in Rural or Off-Road Environment

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    Abstract—This paper presents an environment-detection-and-mapping algorithm for autonomous driving that is provided in real time and for both rural and off-road environments. Environment-detection-and-mapping algorithms have been de-signed to consist of two parts: 1) lane, pedestrian-crossing, and speed-bump detection algorithms using cameras and 2) obstacle detection algorithm using LIDARs. The lane detection algorithm returns lane positions using one camera and the vision module “VisLab Embedded Lane Detector (VELD), ” and the pedestrian-crossing and speed-bump detection algorithms return the position of pedestrian crossings and speed bumps. The obstacle detection algorithm organizes data from LIDARs and generates a local obstacle position map. The designed algorithms have been im-plemented on a passenger car using six LIDARs, three cameras, and real-time devices, including personal computers (PCs). Vehicle tests have been conducted, and test results have shown that the vehicle can reach the desired goal with the proposed algorithm. Index Terms—Autonomous driving, lane detection, obstacle de-tection, pedestrian-crossing detection, speed-bump detection. I

    Comparative treatments of a green tattoo ink with Ruby, Nd: YAG nano- and picosecond lasers in normal and array mode

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    The tattoos removal has become an issue upon spread of the tattooing practice worldwide and hindsight regrets. Lasers are typically used for the purpose, though some colours such as green are considered “recalcitrant” to the treatment. In the current investigation, we aim at determining the efcacy of removal of a green ink water dispersion, using 5 laser treatments: Nd:YAG nano- and picosecond lasers in normal and array mode and Ruby nanosecond laser, keeping the total irradiated energy constant. The UV–Vis spectroscopy of the treated samples indicate that Nd:YAG picosecond laser is most efective, and the Ruby nanosecond laser is the least efcient. Fragment compounds generated from the pigment and siloxanes are common to all treatments, whereas hydrocarbon emerge by a larger amount upon Nd:YAG nanosecond treatment. Fibres are formed upon picosecond treatments and when operating in array mode, and lamellae are achieved by Ruby nanosecond laser treatment. Residual particles suspensions are very heterogeneous upon nanosecond treatments

    Expanding the circularity of plastic and biochar materials by developing alternative low environmental footprint sensors

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    Flexible screen-printing technology combined with the use of a nano/material coating for improving electrode functionalities boosted the manufacturing of highly sensitive electrochemical sensors addressing the need for fast and easy-to-handle tests in different application fields. However, due to the large-scale production and disposable and single-use nature of these devices, their environmental footprint should be taken into careful consideration. Herein, the innovative reuse of post-consumer polyethene terephthalate (PET) plastics as an alternative substrate coupled with biochar as an environmentally friendly and cost-effective modifier is described as a sustainable alternative for the production of robust electrochemical sensors. The good printability of reused plastics with graphite inks despite the chemical heterogeneity, different crystallinity, and surface roughness was demonstrated using atomic force microscopy and attenuated total reflection Fourier transform infrared spectroscopy. Functionalization with brewers' spent grain biochar enabled the fabrication of highly performing electrochemical sensors for nitrite detection in water having a limit of detection and a limit of quantification of 3.3 nM and 10.3 nM, respectively, with a linear range spanning from 0.01 to 500 & mu;M, and good reproducibility (RSD% 8%). The innovative intervention of the biochar-multilayer system markedly enhanced the electron transfer process at the electrode interface while simultaneously serving as an absorptive material for the investigated analyte. This work lays a foundation for repurposing end-of-life plastics for the electronics industry and presents a customizable reuse strategy aimed to keep the value of plastics in the economy and reduce waste and leakage into the natural environment

    Interstitial pneumonia with autoimmune features and undifferentiated connective tissue disease: Our interdisciplinary rheumatology-pneumology experience, and review of the literature

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    Background: Interstitial lung diseases (ILDs) are a heterogeneous group of disorders characterized by inflammation and/or fibrosis of the lungs, varying from idiopathic interstitial pneumonias to secondary variants, including the ILDs associated to connective tissue diseases (CTDs). In addition, a number of patients are recognized as unclassifiable ILD (U-ILD), because of the inability to reach a definite diagnosis; some of them show autoimmune manifestations not fulfilling the classification criteria of a given CTD. The term interstitial pneumonia with autoimmune features (IPAF) has been recently proposed for this particular ILD subset. Methods: Here, we report our experience resulting from the integrated - pneumology/rheumatology - approach to patients with suspected ILDs or CTDs referred to our university-based Center for the Rare Pulmonary Diseases and Rheumatology Unit, from January 2009 to June 2015, with particular attention to the above-mentioned U-ILD, IPAF, and undifferentiated connective tissue disease (UCTD). The comparative analysis of these clinical variants was carried out; moreover, the observed findings were compared with the results of the updated review of the literature. Results: After the first clinical assessment, the U-ILD were identified in 50 patients; afterwards, on the basis of clinico-serological and radiological findings U-ILD group was subdivided into 2 subgroups, namely U-ILD without any clinical extra-thoracic manifestations and/or immunological alterations (15 pts) and IPAF according to the above-mentioned classification criteria (35 pts). Patients with either IPAF or U-ILD were compared with a series of 52 stable UCTD (disease duration ≥. 3. years), followed at our Rheumatology Unit. Some important differences were evidenced among the 3 series of U-ILD, IPAF, and UCTD: firstly, female gender was more frequent in patients with UCTD (86%) or IPAF (69%) compared with U-ILD (60%) or idiopathic pulmonary fibrosis (24%; p = 0.001). In addition, UCTD patients were younger and showed longer disease duration. More interestingly, both UCTD and IPAF series show a comparable prevalence of various clinical manifestations, with the exception of the interstitial lung involvement detectable in a very small percentage of UCTD patients.Concordantly, the review of the literature evidenced two main subsets of U-ILD, one is characterized by isolated unclassifiable interstitial pneumonia and another one composed by subjects with clinically prevalent lung involvement in the setting of not definite CTD, the recently proposed IPAF. Conclusion: We hypothesize that IPAF and UCTD might represent two clinical variants of the same systemic autoimmune disorders. The marked difference regarding the prevalence of ILD, which is the clinical hallmark of IPAF but very rare in UCTD, may at least in part reflect a selection bias of patients generally referred to different specialist centers, i.e. pneumology or rheumatology, according to the presence/absence of clinically dominant ILD, respectively. Well-integrated, interdisciplinary teams are recommended for the assessment and management of these patients in the clinical practice. Finally, the cooperation between multidisciplinary groups with different experiences may be advisable for a validation study of the proposed nomenclature and classification criteria of these indefinable ILD/CTD variants

    Morbidity and Mortality in Patients with Idiopathic Pulmonary Fibrosis Undergoing Diagnostic Surgical Lung Biopsy

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    Morbidity and Mortality In Patients With Idiopathic Pulmonary Fibrosis Undergoing Diagnostic Surgical Lung Biopsy.Previous studies have shown conflicting results about safety of surgical lung biopsy (SLB) in usual interstitial pneumonia (UIP)/idiopathic pulmonary fibrosis (IPF) patients. Study design: we performed a retrospective analysis of all patients who underwent SLB between 2003 and 2013 at the University Hospital of Modena (Italy), to assess morbidity and mortality among patients with UIP/IPF , as compared to patients with other diffuse parenchymal lung diseases (non UIP/IPF). Results: we analyzed 73 patients with (n=29) and without (n=44) UIP/IPF, in which medical history, histology, and survival status were collected. UIP/IPF was diagnosed according to international guidelines. In 59 patients lung biopsy was performed via video-assisted thoracoscopy; in 14 patients thoracotomy was conducted. No intraoperative complications were observed. Postoperative complications were not significantly different between groups and consisted of fever (n=1 in UIP/IPF group; n=4 in non-UIP/IPF group), pneumothorax (n=1 in non-UIP/IPF), pleural effusion (n=1 in non-UIP/IPF), and acute exacerbation (n=1 in both groups, who died). There was no 30-day, 60-day and 90-day mortality. Conclusions: we conclude that surgical lung biopsy can be safely performed in patients with suspected UIP/IPF
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