The present thesis is aimed at the development of a Windows Presentation Foundation (WPF) graphic application which can be used for the display and editing of the granule patterns of marble textures. Granule patterns gained from thin sections make the classification of marbles possible. With the help of this application users are capable of running image processing algorithms that identify granules and eventually may compare the results with the original images. These algorithms require subsequent human corrections and the main focus of the application is directed to this phase ,i.e . granule patterns may be modified, incorrectly detected granules may be separated or melted together. After the feeding in and pre-processing of images the user may alternatively apply special algorithms and manual editing functions in the framework of a specific graphic program. At the same time the usual navigation, saving and loading functions remain available as well. The program was created using .NET Framework 4.5, and written in C# language with Visual Studio 2013.