sbrunner/deskew

Deskew is a command line tool for deskewing scanned text documents. It uses Hough transform to detect "text lines" in the image. As an output, you get an image rotated so that the lines are horizontal.

Automatically extract documents from images and perspectively correct them with classic computer-vision algorithms. In maintenance mode. Check out its successor at:

ICIP 2022: Adaptive Radial Projection on Fourier Magnitude Spectrum for Document Image Skew Estimation

Scan Tailor Experimental is an interactive post-processing tool for scanned pages.

A document scanner implemented with opencv.js

Document image dewarping library using a cubic sheet model

Clean, deskew, and enhance photographed or scanned PDFs and images into crisp, high-contrast documents locally.

ScanTailor Advanced is the version that merges the features of the ScanTailor Featured and ScanTailor Enhanced versions, brings new ones and fixes.

OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched