Window filtering methods were modified to analyse megascopic textural information acquired from banded bituminous coal seams in the field. Although banding texture directly influences the physical properties of coal, methods for its characterisation and analysis are poorly developed. Banding texture was obtained manually from the coal face and core at a minimum resolution of 1 mm. Window filtering was used to determine the optimum resolution (30-50 mm) required for accurate discrimination of coal lithotypes by either manual or image analysis methods. Methods used to automate this procedure and their problems are discussed.