gImageReader — The Complete Guide: Free OCR That Turns Scans and PDFs Into Searchable Text
gImageReader is an open-source (GPL-3.0) graphical interface to the Tesseract OCR engine. Engineering offices pile up scanned specifications, old standards, letters and drawings that exist only as images — gImageReader turns them into text you can search, copy from and quote in a report.
gImageReader
gImageReader project
Graphical OCR built on Tesseract — turn scanned pages and PDFs into text or a searchable PDF.
Get it from the vendorWhat you get
- Many input sources — image and PDF files, a scanner, the clipboard or a screenshot.
- Area selection — mark text blocks by hand or let the program detect them.
- Several pages at once — recognise a whole document in one run.
- Three output formats — plain text, hOCR or a searchable PDF.
- Spell-checking — fix recognition errors before saving.
Tips for good results
Recognition quality depends mostly on scan quality: scan at a sufficient resolution, straight and with good contrast. Choose the recognition language that matches the document, and always check numbers and tables — that is where a recognition error matters most. The program is available for Windows and Linux.
Related tools
To add a text layer to PDF files in batches from the command line — OCRmyPDF. To scan straight from the scanner with OCR — NAPS2. To grab text from a region of the screen — NormCap.
Tesseract OCR
Tesseract OCR project
The open OCR engine behind many tools — turns scans into text in more than 100 languages.
Get it from the vendor
OCRmyPDF
OCRmyPDF project
Adds a searchable text layer to scanned PDFs — old reports, standards and drawings become searchable.
Get it from the vendor
NAPS2
Ben Olden-Cooligan
Scan documents straight to searchable PDF with built-in OCR — delivery notes, minutes and marked-up drawings from site.
Get it from the vendorNormCap
dynobo
A screenshot tool that captures text instead of images — mark an area and the text goes to the clipboard.
Get it from the vendorThe bottom line
gImageReader is a simple way to turn an archive of scans into useful documents — free, open source and with no restriction on commercial use.