Search results for "Computer Vision"
showing 10 items of 2353 documents
Error and Uncertainty Analysis of Non-Uniform Residual Stress Evaluation by Using the Ring-Core Method
2016
Like other mechanical methods used for the residual stress evaluation on a generic structural component, the Ring-Core Method (RCM) is potentially subjected to various error sources that in some particular experimental conditions can lead to significant errors and/or uncertainties on the computed residual stresses. The accuracy of the residual stresses computed by the RCM can be improved by a proper error analysis that allows the user to correct the systematic errors, as well as to evaluate the remaining stress uncertainty due to the random errors. Therefore, in order to give a contribution to the accuracy of the RCM, in the present work the list of the main error sources is presented and t…
A Correlation Retina in Standard 0.6um : Application in Positioning System
2003
International audience; We have designed and fabricated a programmable retina that is capable of recognizing patterns stored in memory in real-time. Each of the pixels of the retina is composed of a photodiode and an electronic device used during the programming phase to digitize the image of the pattern to recognize into a binary image stored in latches. The array of pixels is thus partitioned into two complementary disjoint sub-sets with all the photodiodes of the same sub-set connected together in order to obtain the sum total of the currents. During the analysis phase, an optical correlation between the projected image and the reference binary image memorized in the circuit is done. The…
A New Method to Measure 3D Textile Defects by Using Dual-lens Camera
2013
International audience; Industrial textile fabric with functionalization always has a high standard requirement. Take polytetrafluoroethylene (PTFE) conveyor belt as an example, the base fabrics must be of first-rate quality, with no weaving faults or broken fibers on coated surface [1]. In a previous work, we have proposed an original method to measure the height of the fiber based on variable homography. This measurement is based on a single camera acquiring two successive frames. This scheme is working well, but measurement depends on conveyor speed used for scrolling fabric. In this paper, we propose an improvement by using a new acquisition device based on two mini-lenses assembled as …
Frequency mapping in dynamic light emission with wavelet transform
2013
International audience; Dynamic photon emission microscopy is an e cient tool to analyse today's integrated circuit. Nevertheless, the reduction of transistor's dimensions leads to more complex acquisitions where many spots can be seen. A frequency characterization of the whole acquired area can help to have a better understanding of it. With that purpose in mind, a new methodology to draw frequency mapping of dynamic light emission acquisition is reported. It is fully automated and based on wavelet transform and autocorrelation function. Regarding the possible use in an industrial context, the suggested method can help to localize abnormal emission activity and it gives some perspectives o…
3D image acquisition system based on shape from focus technique
2013
agent Agrosup Dijon de l'UMREcolDurGEAPSI; This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed of randomly distributed objects with spatial discontinuities. In agronomic sciences, the 3D acquisition of natural scene is difficult due to the complex nature of the scenes. Our system is based on the Shape from Focus technique initially used in the microscopic domain. We propose to adapt this technique to the macroscopic domain and we detail the system as well as the image processing used to perform such technique. The Shape from Focus technique is a monocular and passive 3D acquisition method that resolves the occlusion problem affecting…
Drosophila-inspired visual orientation model on the Eye-Ris platform: Experiments on a roving robot
2011
Behavioral experiments on fruit flies had shown that they are attracted by near objects and they prefer front-to-back motion. In this paper a visual orientation model is implemented on the Eye-Ris vision system and tested using a roving platform. Robotic experiments are used to collect statistical data regarding the system behaviour: followed trajectories, dwelling time, distribution of gaze direction and others strictly resembling the biological experimental setup on the flies. The statistical analysis has been performed in different scenarios where the robot faces with different object distribution in the arena. The acquired data has been used to validate the proposed model making a compa…
On Detection of Yaw and Roll Angle Information for Vehicle Oblique Crash using Hough Transform
2014
When performing vehicle crash tests, it is common to capture high frame rate video (HFR) to observe the vehicle motion during the impact. Such videos contain a lot of information, especially when it comes to geometric data. The yaw and roll angles from the HFR video is detected by using the Hough Transform and Matlab's Image processing Toolbox. The measured Yaw angle from the HFR video are compared with real life test data captured with a gyroscopic device inside the vehicle during the oblique vehicle impact.
Detection of surfaces for projection of texture
2007
Augmented reality is used to improve color segmentation on human's body or on precious no touch artefacts. We propose a technique based on structured light to project texture on a real object without any contact with it. Such techniques can be apply on medical application, archeology, industrial inspection and augmented prototyping. Coded structured light is an optical technique based on active stereovision which allows shape acquisition. By projecting a light pattern onto the surface of an object and capturing images with a camera, a large number of correspondences can be found and 3D points can be reconstructed by means of triangulation.
Phase imaging via compressive sensing
2013
This communication develops a novel framework for phase imaging at optical wavelength by merging digital lenless phase-shifting holography with single-pixel optical imaging based on compressive sensing.
Patterned wafer segmentation
2003
This paper is an extension of our previous work on the image segmentation of electronic structures on patterned wafers to improve the defect detection process on optical inspection tools. Die-to-die wafer inspection is based upon the comparison of the same area on two neighborhood dies. The dissimilarities between the images are a result of defects in this area of one of the die. The noise level can vary from one structure to the other, within the same image. Therefore, segmentation is needed to create a mask and apply an optimal threshold in each region. Contrast variation on the texture can affect the response of the parameters used for the segmentation. This paper shows a method to antic…