TOpenALPR

TOpenALPR is a Delphi binding for OpenALPR - Automatic License Plate Recognition library.

Building examples

All examples were tested in Delphi 10.2 Tokyo Starter (32-bit). Microsoft Visual C++ 2015 Redistributable must be installed on the computer.
TOpenALPR requires build of main library that includes C binding. However latest release (2.3.0) does not export C functions, this functionality was implemented later.

1. Download and unpack OpenALPR 2.3.0. Copy files:
   • all files and sub-directories openalpr_32\runtime_data to bin\runtime_data
   • all files and sub-directories openalpr_32\samples to bin\samples
   • openalpr_32\openalpr.conf to bin\openalpr.conf
   • openalpr_32\liblept170.dll to bin\liblept170.dll
   • openalpr_32\opencv_ffmpeg300.dll to bin\opencv_ffmpeg300.dll
   • openalpr_32\opencv_world300.dll to bin\opencv_world300.dll
   • openalpr_32 directory can now be deleted
2. Download and unpack openalpr-master.zip. Copy openalpr.dll to bin\openalpr.dll
3. Open and compile example project:

   • examples\delphi-console. Detect plates in image file samples\eu-1.jpg and write to console output, similar to alpr.exe that is distributed with OpenALPR.

   • examples\delphi-vcl-image. Detect plates in JPG, PNG, BMP and GIF images.
     Operates in three modes:

     • View image: View input image and output with detected plates.
     • Draw detection mask: Press LMB to draw area to be detected, RMB to erase, MMB to erase whole area.
     • Select ROI (Region of Interest): Select detection region (rectangle).

   • examples\delphi-vcl-video. Play samples\eu-clip.mp4 and detect plates. Requires Delphi-OpenCV.
     OpenCV version 3.x should be enabled in source\OpenCV.inc (set {.$DEFINE DelphiOCVVersion_29} and {$DEFINE DelphiOCVVersion_30}) before compiling this example. Otherwise executable will search for OpenCV 2.x files but they are not present in bin directory.

License

TOpenAlpr is licensed under the MIT license. For OpenALPR binaries and usage, follow the original license.