TTesseractOCR4

TTesseractOCR4 is a Object Pascal binding for tesseract-ocr 4.x - an optical character recognition engine.

Building examples

Examples were tested in Delphi 10.2.3 (32-bit build for Windows) and Lazarus 1.8 (32-bit build for Windows and Linux in Ubuntu 18.04).

Clone this repository to a local folder.
Obtain Tesseract 4.x binaries. I recommend using latest version, build from master branch of the tesseract project.

Windows: Precompiled binaries can be found in lib\tesseractocr-master.zip. Unpack and copy all DLL files to bin\.
Microsoft Visual C++ 2017 Redistributable x86 must be installed on the computer.
Linux: sudo apt install tesseract-ocr.
This will also install required shared libraries (liblept5 and libtesseract4).
Common: Set {$DEFINE USE_CPPAN_BINARIES} accordingly in tesseractocr.consts.pas if using Tesseract libraries built with CPPAN (defined as default).

Download trained language data files from tesseract-ocr/tessdata/ to bin\tessdata.
All examples in this repository require English data file (eng.traineddata).
Additionally examples\delphi-console-pdfconvert example requires osd.traineddata and pdf.ttf files.
Linux: Tested with language data from tesseract-ocr/tessdata_fast
Open and compile example project:
- examples\delphi-console-simple. Recognize text in samples\eng-text.png and write to console output
- examples\delphi-vcl-image
  
  4 tabs:
  - Image: View input image
  - Text: Recognized text coded as UTF-8
  - HOCR: Recognized text in HTML format
  - Layout: View page layout (paragraphs, text lines, words...)
- examples\delphi-console-pdfconvert. Convert samples\multi-page.tif (multiple page image file) to a PDF file
- examples\lazarus-console-simple. examples\delphi-console-simple for Lazarus

MIT