README

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).

1. Clone this repository to a local folder.
2. 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).
3. 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
4. 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

License

MIT