Underlinings recognition capabilities

Waivy underlining
wavy hand-written underlinings
Non-homogenous underlining
non-homogenous background
Dark background image of an underlining
dark background
Zoomed-in image of an underlining
zoomed-in text
Underlining on a transparent paper
transparent paper (letters from the other side in the background)
Underlinings that require perspective correction
perspective correction

A glimpse into the processing steps

original photo
original photo
arrow-right sign
Image converted to black and white
converted to black and white
arrow-right sign
image after applying connected component analysis
applied connected component analysis
arrow-right sign
Image with short connected components filtered out
filtered out short connected components
arrow-right sign
Multi-page document
processed photo with underlining removed
plus sign
extracted underlining
extracted underlinings