deskewing

Rotating a photographed or scanned page back to level, undoing the small tilt a camera or scanner almost always adds.

Deskewing corrects the small rotation a photographed or scanned page almost always has, so every line of text sits level again. A pipeline finds the single skew angle first, often from the shared tilt of the text lines a detection pass already found, then rotates the whole page back by the negative of that angle using the same 2D rotation transform an affine transform applies to a whole image.

Examples

A phone photo of a receipt tilts 2.6 degrees off level; deskewing rotates the whole image back by -2.6 degrees before detection runs.