This paper describes a new computer-aided digital image analysing method with self-developed modifications of  public domain software (Scione Image 4.02b) for quantification of geometric and colour-defined characters of patches. Wedemonstrate the method on Bombina bombina and B. variegata and their natural hybrids, separating the two species and defining intermediate specimens according to their belly colour pattern. Belly images of 20 B. bombina, 20 B. variegata and five of their hybrids were processed and analysed, using four patch size- and shape-related characters (patch density, area ratio, ratio of mean patch area and mean patch perimeter, circularity) and three colour-related characters (red, green and blue components). Descriptive statistics (Student’s  t-test) and canonical variate analysis were used to discriminate among the three groups of specimens, and the results were compared with results based on independent genetic data. The two species significantly differed in all the geometric and two of the colour characters, and were clearly separated by the multivariate analysis, while the hybrid specimens had intermediate features.