A scanned document image, including add-on information such as handwritten annotations
in addition to printed text lines, is processed by a handwriting detection method.
First, at least one projection histogram is generated from the scanned document
image. A regular pattern that correlates to the printed text lines is determined
from the projection histogram. Second, connected component analysis is applied
to the scanned document image to generate at least one merged text line. Each merged
text line relates to at least one of the handwritten annotation and the printed
text line. By comparing the merged text lines to the regular pattern of the projection
histograms, the printed text lines are discriminated from the handwritten annotations.
