Calculate the denseness (proportion of black pixel in relation to the total number of pixels) for a given number of sections (n_sections). n_sections should be set as a number, in this situation denseness_row will break the original matrix in slices, and apply denseness_total function for each section. For instance, in a matrix of 1000x1000 if n_sections = 10, it will break to 10 sections of 100x1000 and analyze it. In other words, the sections will be the following sections of the original matrix [1:100, 1:1000] , [101:200, 1:1000] , [201:300, 1:1000] , [301:400, 1:1000] , [401:500, 1:1000] , [501:600, 1:1000] , [601:700, 1:1000] , [701:800, 1:1000] , [801:900, 1:1000] , [901:1000, 1:1000] .The default for parameter n_sections is "all", it will calculate denseness for each row of pixel. In other words, it will break the image in a number of section equal to the image pixel height.