Search results for "Machine"

2015

Abstract. In X-ray computed microtomography (μXCT) image processing is the most important operation prior to image analysis. Such processing mainly involves artefact reduction and image segmentation. We propose a new two-stage post-reconstruction procedure of an image of a geological rock core obtained by polychromatic cone-beam μXCT technology. In the first stage, the beam-hardening (BH) is removed applying a best-fit quadratic surface algorithm to a given image data set (reconstructed slice), which minimizes the BH offsets of the attenuation data points from that surface. The final BH-corrected image is extracted from the residual data, or the difference between the surface elevation valu…

Improvement of multimodal images classification based on DSMT using visual saliency model fusion with SVM

2019

Multimodal images carry available information that can be complementary, redundant information, and overcomes the various problems attached to the unimodal classification task, by modeling and combining these information together. Although, this classification gives acceptable classification results, it still does not reach the level of the visual perception model that has a great ability to classify easily observed scene thanks to the powerful mechanism of the human brain.
  In order to improve the classification task in multimodal image area, we propose a methodology based on Dezert-Smarandache formalism (DSmT), allowing fusing the combined spectral and dense SURF features extracted …

Training label cleaning with ant colony optimization for classification of remote sensing imagery

2015

This paper presents an original approach for improving performances of the supervised classifiers in remote sensing imagery by proposing a technique to refine a given training set using Ant Colony Optimization (ACO). The new method called ACO-Training Label Cleaning (ACO-TLC) applies ACO model for selection of the significant training samples from a given set of labeled vectors in order to optimize the quality of a supervised classifier. This means to retain the most informative samples and to remove the uncertain or misclassified training samples, which lead to classification errors. As a result of the selection process, we can obtain a purified training set. The proposed model is implemen…

HD-RTI: an adaptive multi-light imaging approach for the quality assessment of manufactured surfaces

2021

International audience; Reflectance Transformation Imaging (RTI) is a technique for estimating surface local angular reflectance from a set of stereo-photometric images captured with variable lighting directions. The digitization of this information fully fits into the industry 4.0 approach and makes it possible to characterize the visual properties of a surface. The proposed method, namely HD-RTI, is based on the coupling of RTI and HDR imaging techniques. This coupling is carried out adaptively according to the response at each angle of illumination. The proposed method is applied to five industrial samples which have high local variations of reflectivity because of their heterogeneity of…

Human-Robot Cooperation for Surface Repair Combining Automatic and Manual Modes

2020

[EN] This article develops a human-robot cooperation to carry out treatments such as sanding, polishing, etc. on the surface of a known rigid object. For this purpose, a vision system is considered to get the object location to ensure not only the perpendicularity of the obot tool to the object surface but also a smooth approach of the tool to the surface. In order to add flexibility, the proposal includes the simultaneous combination of automatic and manual modes of operation. Thus, the human user can guide the robot tool to treat arbitrary areas (manual mode) and, when the operator releases the tool, the robot goes into the automatic mode to treat prior established areas. The method uses …

Automatic correction of the effects of the light source on spherical objects. An application to the analysis of hyperspectral images of citrus fruits

2008

This study proposes a method for correcting the adverse effects produced by the curvature of spherical objects in acquiring images with a computer vision system. Its suitability has been illustrated in a specific case of citrus fruits. The images of this kind of fruit are darker in areas nearer the edge than in the centre, and this makes them more difficult to analyse. This methodology considers the fruit as being a Lambertian ellipsoidal surface and produces a 3D model of the fruit. By doing it becomes possible to calculate the part of the radiation that should really reach the camera and to make the intensity of the radiation uniform over the whole of the fruit surface captured by the cam…

Considerations on Cutting Regime Influence of NC Laser Cutting Machine Tool on Processed Surface Quality

2015

This paper presents the study of the influence of cutting parameters on surface quality in laser cutting of metallic materials. In this paper, it is shown which of the cutting parameters have the greatest influence on the quality of the processed surfaces by measuring various roughness parameters. After the experimental research was carried out a ranking of the factors of influence on the response functions was made, also graphs of dependency to various parameters of roughness were made.

Deep Gaussian Processes for Geophysical Parameter Retrieval

2018

This paper introduces deep Gaussian processes (DGPs) for geophysical parameter retrieval. Unlike the standard full GP model, the DGP accounts for complicated (modular, hierarchical) processes, provides an efficient solution that scales well to large datasets, and improves prediction accuracy over standard full and sparse GP models. We give empirical evidence of performance for estimation of surface dew point temperature from infrared sounding data.

Biomechanical comparison between the modified rolling-hitch and the modified finger-trap suture techniques

2016

Purpose: The purpose of this study was to characterize the biomechanical effect of two grasping suture techniques used during ligament reconstruction: the modified rolling-hitch (MRH) and the modified finger-trap (MFT). Methods: Flexor profundus tendons were harvested from fresh pig hind-leg trotters. Each specimen was mounted on an electro-mechanic universal testing machine (Instron 3367). In half of all tendons (15 specimens), the suture was passed around the tendon following the MRH knot (Group 1). In the remaining half of all tendons (15 specimens), the suture was passed over a distance of 30 mm according to the MFT suture technique (Group 2). As per standard intra-operative technique, …

Fusing optical and SAR time series for LAI gap filling with multioutput Gaussian processes

2019

The availability of satellite optical information is often hampered by the natural presence of clouds, which can be problematic for many applications. Persistent clouds over agricultural fields can mask key stages of crop growth, leading to unreliable yield predictions. Synthetic Aperture Radar (SAR) provides all-weather imagery which can potentially overcome this limitation, but given its high and distinct sensitivity to different surface properties, the fusion of SAR and optical data still remains an open challenge. In this work, we propose the use of Multi-Output Gaussian Process (MOGP) regression, a machine learning technique that learns automatically the statistical relationships among…