Within the field of industrial image processing the use of colour cameras becomes ever more common. Increasingly the established black and white cameras are replaced by economical single-chip colour cameras with Bayer pattern. The use of the additional colour information is particularly important for recognition or inspection. Become interesting however also for the geometric metrology, if measuring tasks can be solved more robust or more exactly. However only few suitable algorithms are available, in order to detect edges with the necessary precision. All attempts require however additional computation expenditure. On the basis of a new filter for edge detection in colour images with subpixel precision, the implementation on a pre-processing hardware platform is presented. Hardware implemented filters offer the advantage that they can be used easily with existing measuring software, since after the filtering a single channel image is present, which unites the information of all colour channels. Advanced field programmable gate arrays represent an ideal platform for the parallel processing of multiple channels. The effective implementation presupposes however a high programming expenditure. On the example of the colour filter implementation, arising problems are analyzed and the chosen solution method is presented.
This paper explains the evaluation of special geometrical measuring problems at production of wind energy plants. The paper contains the concept and theoretical solutions of a measuring system for large diameters. Different measuring principles were reviewed for the measuring problem and a possible solution is described. At the end the results of the evaluated concept are compared with the high end and the low budget solution.
Abstract 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.
Coordinate measuring machines are high precession all-rounder in three dimensional measuring. Therefore the versatility of parameters and expandability of additionally hardware is very comprehensive. Consequently you need much expert knowledge of the user and mostly a lot of advanced information about the measuring object. In this paper a coordinate measuring machine and a specialized measuring machine are compared at the example of the measuring of eyeglass frames. For this case of three dimensional measuring challenges the main focus is divided into metrological and economical aspects. At first there is shown a fully automated method for tactile measuring of this abstract form. At second there is shown a comparison of the metrological characteristics of a coordinate measuring machine and a tracer for eyeglass frames. The result is in favour to the coordinate measuring machine. It was not surprising in these aspects. At last there is shown a comparison of the machine in front of the economical aspects.
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.
This paper describes the disadvantages of the quality assurance of meat according germ contaminations. Because of the latest regulations and the consumption behavior of the costumers there is a need for faster testing methods. One possible solution could be fluorescent markers which react with specific germs. The fluorescence effect could be acquired with an image processing system. The requirements and possible solutions of such image processing system are presented in this paper.
The field of quality assurance in the industrial production is closely connected to the precise measuring of the products. Several measuring methods are used, like optical, capacitive or tactile ones. There is perennially a pinch for time the measure each needed deviation in a little while, especial when a total inspection is necessary. Optical coordinate measuring machines are especially qualified for this aim, because of their possibility to acquire a lot of measuring points in one measuring step. Because of the blocked optical path, also these machines are finished when the device is located behind an undercut. This is for example the case by the ground of a groove on the inside of a cylinder. Then it is necessary to deflect the beam of the machine as you can see in Fig. 1. That is the reason why the Department of Quality Assurance from the Faculty of Mechanical Engineering of the Technical University of Ilmenau promoted by the Federal Ministry of Economics and Technology within the framework of the InnoNET program is researching for a new procedure for detecting deviations behind an undercut by using optical coordinate measuring machines. Therefore several possibilities for beam deflexion, illuminations scenes, foci criteria, minimum of detecting field and the needed optical magnification were discussed.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
