3) Slant Correction: After the slope correction, we apply a
slant correction to normalize the writing paths. In normal handwriting
of Latin-script languages, the most common directions
are vertical (or near-vertical) strokes, such as the letter “I” or
the first and the last part of the letter “M.” Also here, different
users tend to write with different slants [see Fig. 6(c)]. In order
to normalize for slant, we compute a histogram of directions for
each stroke by computing the deltas between every pair of points
between pen-down and pen-up events, determine the dominant
direction, and then apply a shear transform to align it to the
vertical [see Fig. 6(d)].