CARRIDA SDK Documentation  Version 4.7.0

CARRIDA is a dynamic library for automated license plate recognition (ALPR) designed to run under the Linux and Windows operating system. For both systems you can choose between the 32-bit or 64-bit version of the engine.

The purpose of lprcarrida is to detect and read vehicle license plates from still images and video streams. The library has the following features:

  • Practically no configuration needed
  • Trainable for any symbols (support for new countries)
  • Any number of license plates per image can be detected
  • State recognition support
  • Computation of confidences for detected plates as well as for individual characters
  • Exact position of detected plates as well as all individual characters within the image is delivered
  • Reading of license plates with two rows
  • Reading of license plates with stacked characters
  • Robust against image varying quality (illumination, contrast, noise), rotation etc.
  • Thread safe implementation

The Linux version of lprcarrida runs on Intel architectures as well as on ARM machines (ARM Cortex-A8 processors and above, NEON instruction set required). The programming interface for both supported operating systems is identical, so that it iss easy to port your applications from Windows to Linux and vice versa.

CARRIDA can be distributed

  • either with software protection
  • or with hardware protection (USB dongle key is requiered to use the library)

To support fast and easy utilization of various video sources, svcapture library is delivered (currently Windows version only). This library allows to aquire frames from following sources:

  • video files having varios video formats
  • rtsp and http live streams
  • folders with image files

To utilize the svcapture library, a 3rd party video I/O library GStreamer has to be installed (see