Search results for "ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION"
showing 10 items of 982 documents
Perspective-n-Learned-Point: Pose Estimation from Relative Depth
2019
International audience; In this paper we present an online camera pose estimation method that combines Content-Based Image Retrieval (CBIR) and pose refinement based on a learned representation of the scene geometry extracted from monocular images. Our pose estimation method is two-step, we first retrieve an initial 6 Degrees of Freedom (DoF) location of an unknown-pose query by retrieving the most similar candidate in a pool of geo-referenced images. In a second time, we refine the query pose with a Perspective-n-Point (PnP) algorithm where the 3D points are obtained thanks to a generated depth map from the retrieved image candidate. We make our method fast and lightweight by using a commo…
A Study on the Impact of Spectral Characteristics of Filters on Multispectral Image Acquisition
2013
International audience; In every aspect, filter design plays an important role in an image acquisition system based on a single image sensor and a colour filter array (CFA) mounted onto the sensor. Complementary CFAs are used by some colour cameras in the interest of higher sensitivity, which motivated us to employ filters of wide pass bands in the effort to adapt CFA for multispectral image acquisition. In this context, filter design has an effect on the accuracy of spectrum reconstruction in addition to other aspects. The results show that wider bandwidths in general result in more faithful spectrum reconstruction and higher signal-to-noise performance.
3D ACQUISITION SYSTEM APPLIED TO AGRONOMIC SCENES
2012
International audience; To improve results in automatic wheat ear counting by proxy-detection for early yield prediction, we need depth information of the scene. In this paper, we describe our 3D acquisition system dedicated to reconstruction of agronomic scenes. This system is composed of a camera mounted on a linear displacement driven by a microcontroller. The linear displacement allows acquiring a set of images in different distances to the scene. This image stack is used to apply shape from focus technique which is a passive and monocular 3D reconstruction method. This technique consists in the application of a focus measure for every pixel in the stack. An approximation method is used…
A 3-D simulation with virtual stereo rig for centrifugal fertilizer spreading
2012
International audience; Stereovision can be used to characterize of the fertilizer centrifugal spreading process and to control the spreading fertilizer distribution pattern on the ground reference. Fertilizer grains, however, resemble each other and the grain images contain little information on texture. Therefore, the accuracy of stereo matching algorithms in literature cannot be used as a reference for stereo images of fertilizer grains. In order to evaluate stereo matching algorithms applied to images of grains a generator of synthetic stereo particle images is presented in this paper. The particle stereo image generator consists of two main parts: the particle 3D position generator and…
Multi-modal image fusion for small animal studies in in-line PET /3T MRI
2015
Congrès sous l’égide de la Société Française de Génie Biologique et Médical (SFGBM).; National audience; In the framework of small animal multi-modal imaging, the current progression of the IMAPPI project is illustrated by the design of an in-line PET/MRI prototype, coupled to a dedicated multi-resolution registration method allowing the robust fusion of data coming from both modalities. The first results show a good alignment of the data from tumor imaging at the level of the abdomen.
Analysis of georeferenced landscape pictures extracted from public picture collections
2019
National audience; Today photo-sharing websites allow citizen to share their pictures. Pictures taken by sensor-equipped devices such as smartphones or tablet-computers keep the information where (in terms of coordinates and azimuth angle), when and with which device a picture has been taken.We have developed a method that uses the coordinates of the camera position as well as the azimuth angle, the focal length and the crop factor in order to calculate a 3D field of view of a picture using a digital terrain model (DTM). This field of view can thereafter be used for the determination of interest in spatial features. Similar methods that are based on viewsheds have been described by Tenerell…
Quelques paradoxes du corpus saussurien : le « psychologisme » de Saussure à l’« âge psychologique » des sciences humaines
2021
Conférence en ligne (Zoom); International audience; No abstract
A Continuous Time Pattern Recognition Retina
2002
International audience; We present in this paper a pattern recognition retina operating in continuous time. During a programming phase, the reference image is acquired by the sensor. After thresholding, the resulting binary image is stored in the sensor's pixels. During the recognition phase, the retina calculates, in an analog way and in continuous time, the zero displacement intercorrelation of the current image with the binary reference image and its complement. These two intercorrelation values are output as currents. By comparing these currents to expected values, determined during the programming phase, a shift of the pattern or a difference between the observed and programmed pattern…
Optimal Gabor Filters and Haralick Features for Industrial Polarization Imaging
2011
International audience; During the past decade, computer vision methods for inline inspection became an important tool in a lot of industrial processes. During the same time polarization imaging techniques rapidly evolved with the development of electro-optic components, as e.g. the polarization cameras, now available on the market. This paper is dedicated to the application of polarization techniques for visually inspecting complex metallic surfaces. As we will shortly recall, this consists of a direct image interpretation based on the measurement of the polarization parameters of the light reflected by the inspected object. The proposed image interpretation procedure consists of a Gabor p…
Multi-Scale Feature Extraction for Vehicle Detection Using Phis-Lbp
2018
International audience; Multi-resolutionobjectdetectionfacesseveraldrawbacksincludingitshighdimensionalityproducedby a richer image representation in different channels or scales. In this paper, we propose a robust and lightweight multi-resolution method for vehicle detection using local binary patterns (LBP) as channel feature. Algorithm acceleration is done using LBP histograms instead of multi-scale feature maps and by extrapolating nearby scales to avoid computing each scale. We produce a feature descriptor capable of reaching a similar precision to other computationally more complex algorithms but reducing its size from 10 to 800 times. Finally, experiments show that our method can obt…