Anodic oxidation of aluminum alloy in a ternary solution of SFS (sulfuric, phthalic and oxalic acids) with 30g of tungsten disulfide (WS2) powder was carried out in order to obtain the aluminum oxide layer named in article as Al2O3/WS2 coatings. The microstructures of surface of obtained coatings were investigated. The subject of the analysis was a threadlike hill structure visible on the surface of coatings as bright ridges. The computer image analysis was performed in order to study the influence of electrolysis time and temperature of acids bath on the volume fraction VV of the area of the surface with filamentous hill’s structure.
Automatic detection of objects is a part of visual systems supporting a quality control system of a manufacturing process. The paper concerns the influence of the resolution of images and the size of detected objects in pixels on measurements results. Test images of the objects of a known size were generated. The values of the perimeter of the objects were compared to the obtained values of measurements on the images with degraded resolution. The process of the degradation of the references images by successive downsizing the resolution, detection and measurements were performed applying automatic algorithm. The analysis of obtained results showed that the size of the analysed objects on the digital images plays an important role in reliability and accuracy of the measurement. The author concludes that, in order to avoid a bias in measurement caused by insufficient object resolution, the minimal acceptable size of objects on digital images in pixels should be recommended.
Shade effect is a defect of the images very often invisible for human vision perception but may cause difficulties in proper image processing and object detection especially if the aim of the task is to proceed detection and quantitative analysis of the objects. There are several methods in image processing systems or presented in the literature, however some of them introduce unexpected changes in the images, what may interfere the final quantitative analysis. In order to solve this problem, authors proposed a new method for shade correction, which is based on simulation of the image background based on analytical methods which return pixel values representing smooth grey level changes. Comparison of the effects of correction by applying standard methods and the method proposed are presented.
Paper presents the influence of the image resolution on measurement geometric parameters of the objects. Employing as test images the ductile iron structure images allow to analyze the effect of resolution distortion on a model of objects with regular shape. Authors showed on the example images, how decreasing resolution of digital images distorts the value of the parameters describing the shape of the objects, its perimeter and its quantity. The analysis was performed by an automatic algorithm applying image analysis and stereological method.