“…For the Docstrum method [32], its default parameter values K ¼ 5 (the number of nearest neighbours), f t ¼ 2:578 (threshold of connecting components into line), f d ¼ 9 (proportion of letters), f pe ¼ 1:3 (threshold of connecting components into text blocks for perpendicular direction), f pa ¼ 1:5 (threshold of connecting components into text blocks for parallel direction) were substituted with K ¼ 8, f t ¼ 2:578, f pe ¼ 1:1, f pa ¼ 2:112. For ARLSA algorithm [30] the values of parameters were as follows T h ¼ 3:5 (threshold referring to the proportion of component height), c ¼ 0:4 (constant), a ¼ 5 (constant). T max (threshold referring to the number of congruent background pixels) was set as an average of all components.…”