Technology and General Blog

This write-up will go over a checklist of practical “Optical Character Recognition” computer software offered for Linux. An optical character recognition (OCR) program attempts to detect text articles of non-textual content data files whose content cannot be selected or copied but can be seen or examine. For occasion, an OCR software program can determine textual content from photos, PDF or other scanned documents in electronic file formats utilizing a variety of algorithms and AI based mostly options.

These OCR software are especially valuable for changing and preserving previous documents as they can be used to detect text and build electronic copies. Sometimes the recognized text may possibly not be 100% accurate but OCR application gets rid of the require for guide edits to a good extent by extracting as substantially textual content as possible. Manual edits can be created later to boost precision further more and build a person-to-a single replicas. Most OCR application can extract text into separate data files, while some also help superimposing a concealed text layer on first data files. Superimposed textual content permits you to read through written content in authentic print and format but also enables you to choose and duplicate textual content. This procedure is specifically applied to digitize old paperwork into PDF format.

Tesseract OCR

Tesseract OCR is a totally free and open resource OCR software available for Linux. Sponsored by Google, and taken care of by many volunteers, it is in all probability the most thorough OCR suite out there out there that can even defeat some compensated, proprietary answers. It presents command line equipment as properly as an API that you can combine in your very own packages. It can detect text in many languages with great precision. It arrives with a established of pre-experienced details that can be applied to discover and extract textual content. You can also use your have qualified data if you need to have a custom made remedy or you can get much more versions from 3rd events. Tesseract OCR arrives with various detection engines and you can use them according to your desires depending on the installation strategy.

To set up Tesseract OCR in Ubuntu, use the command specified underneath:

$ sudo apt install tesseract-ocr

You can install it in other Linux distributions from default repositories via the offer supervisor. A common AppImage file and a lot more installation guidance are obtainable below.

Tesseract OCR arrives with assistance for detecting English language material by default. If you want to help supplemental languages, you may possibly have to obtain far more language packs. The url provided previously mentioned has directions for installing extra language packs. In Ubuntu, you can instantly discover language packages by working the command down below:

$ apt-cache look for tesseract-ocr-

The command higher than will output offer names for distinctive language packs. Just set up them by jogging a command in the adhering to format:

$ sudo apt install <language-package>

You can get a record of all installed language packs by functioning the command below:

At the time the principal Tesseract OCR package and additional language packages have been mounted, you can commence detecting text from pictures and PDF data files. To extract textual content, use instructions in pursuing formats:

$ tesseract image.png output -l eng

$ tesseract graphic.png output -l eng+spa

$ tesseract graphic.png output -l eng pdf

The initial command will extract text from “image.png” file in “eng” language and retail store it in a file known as “output”. The 2nd command will parse the impression utilizing many language packs. The third command can be made use of to generate a PDF file with a text layer superimposed on the image file.

For additional information and facts on command line utilization of Tesseract OCR, use the adhering to two instructions:

$ tesseract –help

$ man tesseract


gImageReader is a graphical client for the Tesseract OCR motor talked about higher than. You can use it to operate most of the command line alternatives and steps supported by Tesseract OCR, which includes extracting text from many documents, spell-examining the extracted textual content and accomplishing post-processing on the recognized text.

To install gImageReader in Ubuntu, use the command specified underneath:

$ sudo apt put in gimagereader

You can set up it in other Linux distributions from default repositories by way of the package manager. Extra distribution particular deals are available below.


Paperwork is a totally free and open up source document manager. You can use it to effectively take care of your library of files, particularly if you have a massive collection. It also will come with a built-in OCR mode that uses “Pyocr”, a Python module based mostly on Tesseract and Cuneiform OCR engines. Other primary characteristics of Paperwork involve ability to edit scanned files, a look for bar to search document library, capability to type paperwork, scanner aid, and so on.

To put in Paperwork in Ubuntu, use the command specified under:

$ sudo apt install paperwork-gtk

You can install it in other Linux distributions from default repositories via the bundle supervisor. A common flatpak bundle is also available right here.


OCRFeeder is a totally free and open up source graphical OCR software program preserved by the GNOME team. It supports recognizing textual content in several languages and can export information in quite a few file formats. It supports a lot of OCR engines, which includes Tesseract OCR, GOCR, Ocrad and Cuneiform. It also permits you to do some submit-processing to increase formatting and structure of the extracted text content.

To put in OCRFeeder in Ubuntu, use the command specified beneath:

$ sudo apt put in ocrfeeder

You can put in it in other Linux distributions from default repositories by the bundle supervisor. A universal flatpak offer is also out there below.

Note that in my tests, OCRFeeder mounted from Ubuntu repositories came with only one OCR motor. Having said that, the flatpak establish arrived with all 4 supported OCR engines even though it downloaded all around 2GB details. The deal involved in the Ubuntu repository was a lot smaller sized in size.


gscan2pdf is a free of charge and open up resource graphical utility that can determine and extract text from a wide range of file formats. It can directly do the job with scanners to scan papers and then export OCR detected text content material into PDF files. It also supports numerous OCR engines like Tesseract OCR, GOCR, Ocropus and Cuneiform, as lengthy as deals for these engines are put in on your program. Other than immediate scanning of papers, you can also import graphic data files and extract text from them.

To put in gscan2pdf in Ubuntu, use the command specified below:

$ sudo apt put in gscan2pdf gocr cuneiform tesseract-ocr

You can put in it in other Linux distributions from default repositories through the bundle supervisor. Supply code and executable binaries are also readily available below.


These are some of the most beneficial command line and graphical OCR engines and software obtainable for Linux. Tesseract OCR is the most actively formulated and most detailed resource for detecting textual content and it need to be sufficient for most of your requirements. Although you can also try other applications mentioned in this write-up if you are not glad with the final results of Tesseract OCR.

Leave a Reply

Your email address will not be published. Required fields are marked *