A structured LED linear light as an economically priced and technical alternative to a laser line generator

An interesting option for 3D object recognition is the triangulation principle. For this purpose a laser line generator is often used. But other structured linear light sources are also possible. For this the linear light has to have a defined width, brightness and sharpness. The linear light on the object, e. g. a groove, is changed by the object’s surface and is detected by digital image processing. Until now such linear light has been created with the help of a complex visual system using laser diodes. Because of some optical disadvantages of laser light, like speckles, in optical measurement applications, this paper examines the effect of using a structured LED light source instead of the laser generator. Consequently, the focus of this research lies on the necessary width, brightness, sharpness, length and depth of focus of the linear light generated by a LED light source for high-precision measuring. This research has been carried out by extensive computer-aided simulations. Several solutions are given and assessed in this paper

Method for a robust search line based estimation of intensity edge width in blurred gray scale images for quantification of motion- and out-of-focus-blur

This paper presents a robust method for the estimation of the edge width at contours in intensity gray level images to determine the grade of blur respectively motion and out-of-focus blur. There are several methods for estimating of intensity edge width, but a lot of them got as main problem a sensitivity to noise and for this reason large variances of the measuring results. The method bases on a histogram estimation of bright and dark level with respect to the noise followed by a scaling. Afterwards the scaled edge curve is fitted by Gaussian error function for a functional describing of the edge [1]. The fitted edge is following used for calculation of edge width described by Thomas principle used for lens quality estimations [2]. The functionality of the algorithm is evaluated with synthetically noised and realistic captures at different optical magnifications, exposure times and velocities of relative motion between camera and measuring scene. Index Terms- image quality, edge quality estimation, image restoration basics, optical coordinate measurin

An experimental study of motion blur in optical coordinate metrology for dynamic measurements of geometrical features

Published in: Proceedings of the 14th Joint International IMEKO TC1 + TC7 + TC 13 Symposium : "Intelligent quality measurements - theory, education and training" ; in conjunction with the 56th IWK, Ilmenau University of Technology and the 11th SpectroNet Collaboration Forum ; 31. August - 2. September 2011, JenTower Jena, Germany. - Ilmenau : Univ.-Bibliothek, ilmedia, 2011. URN: urn:nbn:de:gbv:ilm1-2011imeko:

A structured LED multi linear light for groove measurement of a spectacle frame

Nowadays, eyeglasses are not only a vision aid, they also are fashion and design articles for the customers. The customer preference for various forms of spectacle frames grows and is served by the different frame manufacturers. This development leads to an increased effort for the production of adapted eyeglass lenses because of the huge range of the different designs and their manufacturing inaccuracies [1]. Therefore it is absolutely necessary to know exactly the coordinates of the ground of the spectacle groove for grinding the glasses well. One non-contact possibility is the triangulation principle. Therefore often a laser line generator is used. But also a structured LED linear light is possible. For this the linear light has to have a defined width, brightness and sharpness. The linear light on the object, here the groove of the frame, is changed by its surface and is detected by a digital image processing [2]. If more information should be detected within one image a multi linear light could be used. Due to this also a structured LED based light source is an economically priced alternative to a multi laser line generator. Consequently, the focus of this research lies on the necessary width, brightness, sharpness, length and depth of focus of the linear light generated by a LED light source for high-precision measuring. This research has been carried out by extensive computer-aided simulations. Index terms – multi linear light, structured LED ligh