In this article the authors propose a method for the automatic analysis of the symmetry of the glass melting process based on a series of images captured by a camera inside a glass furnace. The method is designed for the analysis of two aspects of symmetry: the symmetry of the batch distribution and the symmetry of the temperature distribution. Temperature is assessed from the colour of visible light emitted by surfaces in the tank. The authors have proposed a set of asymmetry indicators that are not influenced by asymmetries that result from glass melting technology (consecutive heating of first one, then the other side of the furnace). A proposed rule-based system deduces the reasons for asymmetries from these asymmetry indicators: whether heating of the left and right hand sides of the furnace is unbalanced or whether chargers are not working properly. A prototype system based on algorithms proposed in this article has been tested at the following glassworks: Warta Glass Jedlice SA; Huta Szkla Orzese; and Stolzle Czestochowa Sp.
