Building a C/C++ Barcode & QR Code Reader for Raspberry Pi with Dynamsoft SDK

Apr 04, 2017

 Barcode

•  RASPBERRY PI
•  CPP
•  BARCODE
•  QR CODE
•  ARM32
•  DBRV9.X

Learn how to effortlessly set up a C/C++ barcode and QR code reader for Raspberry Pi using the Dynamsoft Barcode Reader SDK. This guide is optimized for Raspberry Pi 4 but is compatible with both ARM32 and ARM64 Raspberry Pi OS.

This article is Part 1 in a 16-Part Series.

• Part 1 - Building a C/C++ Barcode & QR Code Reader for Raspberry Pi with Dynamsoft SDK
• Part 2 - CMake: Build C++ Project for Windows, Linux and macOS
• Part 3 - How to Port Visual Studio C++ Project to Linux with CMake
• Part 4 - Insight Into Dynamsoft Barcode SDK Decoding Performance
• Part 5 - Building ARM64 Barcode and QR Code Scanner on Nvidia Jetson Nano
• Part 6 - How to Decode QR Code on Mac with Apple Silicon
• Part 7 - How to Develop a Desktop GUI Barcode Reader with Qt and C/C++
• Part 8 - How to Build a Desktop Barcode Scanner with Webcam Support Using Qt QCamera
• Part 9 - Building Command-line Barcode and QR Code Reader in C++
• Part 10 - How to Build Linux ARM32 and Aarch64 Barcode QR Scanner in Docker Container
• Part 11 - How to Link MSVC DLLs with MinGW GCC in Windows
• Part 12 - Transforming Raspberry Pi 4 into a Barcode Scanner with a C++ App, USB Camera, and OLED Display
• Part 13 - Building Windows Desktop Barcode Reader with Win32 API and Dynamsoft C++ Barcode SDK
• Part 14 - How to Build a Command-Line Barcode Reader with Rust and C++ Barcode SDK
• Part 15 - How to Decode Barcode and QR Code from WebP Images in C++ and Python
• Part 16 - Building a Desktop C++ Barcode Scanner with Slimmed-Down OpenCV and Webcam

About Dynamsoft Barcode Reader SDK

• Support for ARM32 and ARM64.
• Seamless integration with C/C++ projects on Raspberry Pi.

• Download Dynamsoft C++ Barcode SDK v9.x

  

• Activate the SDK with a 30-day free trial license.

Requirements

• Ensure you have CMake installed. Update and install using:

  sudo apt update
  sudo apt install -y cmake
  

Building Barcode and QR Code Reader on Raspberry Pi

1. Create a new C/C++ project with a CMakeLists.txt file.

   

2. Configure the CMakeLists.txt file.

    cmake_minimum_required (VERSION 2.6)
    project (BarcodeReader)
   
    SET(CMAKE_CXX_FLAGS "-std=c++11 -O3 -Wl,-rpath=$ORIGIN")
    SET(CMAKE_INSTALL_RPATH "$ORIGIN")
    SET(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
   
    if(CMAKE_SYSTEM_PROCESSOR STREQUAL armv7l OR ARM32_BUILD)
        MESSAGE( STATUS "Link directory: ${PROJECT_SOURCE_DIR}/platforms/arm32/" )
        link_directories("${PROJECT_SOURCE_DIR}/platforms/arm32/") 
    elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64) 
        MESSAGE( STATUS "Link directory: ${PROJECT_SOURCE_DIR}/platforms/aarch64/" )
        link_directories("${PROJECT_SOURCE_DIR}/platforms/aarch64/") 
    endif()
    include_directories("${PROJECT_BINARY_DIR}" "${PROJECT_SOURCE_DIR}/include/")
    add_executable(${PROJECT_NAME} BarcodeReader.cxx)
    target_link_libraries (${PROJECT_NAME} "DynamsoftBarcodeReader" pthread)
   
    if(CMAKE_SYSTEM_PROCESSOR STREQUAL armv7l OR ARM32_BUILD)
        install (DIRECTORY  "${PROJECT_SOURCE_DIR}/platforms/arm32/" DESTINATION ${PROJECT_SOURCE_DIR}/dist)
    elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64) 
        install (DIRECTORY  "${PROJECT_SOURCE_DIR}/platforms/aarch64/" DESTINATION ${PROJECT_SOURCE_DIR}/dist)
    endif()
   

   We use rpath to make the library search path to be the same as the executable. After running cmake --install ., the library files and executable files will be copied to the dist directory for distribution.

3. In BarcodeReader.cxx, include the DynamsoftBarcodeReader.h file.

    #include "DynamsoftBarcodeReader.h"
   

4. Set the license key for global access. You do not need to set the license key for each instance of the barcode reader.

    if (license)
    {
      char errorMsgBuffer[512];
      // Click https://www.dynamsoft.com/customer/license/trialLicense/?product=dcv&package=cross-platform
      DBR_InitLicense("DLS2eyJoYW5kc2hha2VDb2RlIjoiMjAwMDAxLTE2NDk4Mjk3OTI2MzUiLCJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSIsInNlc3Npb25QYXNzd29yZCI6IndTcGR6Vm05WDJrcEQ5YUoifQ==", errorMsgBuffer, 512);
      printf("DBR_InitLicense: %s\n", errorMsgBuffer);
    }
   

5. Initialize the barcode reader object:

    void *reader = DBR_CreateInstance();
   

6. Configure the parameters of the barcode reader.

    char sError[512];
    PublicRuntimeSettings *runtimeSettings = new PublicRuntimeSettings();
    DBR_GetRuntimeSettings(reader, runtimeSettings);
    runtimeSettings->maxAlgorithmThreadCount = 1;
    runtimeSettings->barcodeFormatIds = BF_ALL;
    DBR_UpdateRuntimeSettings(reader, runtimeSettings, sError, 512);
    delete runtimeSettings;
   

7. Call a decoding method based on your input source.
   • DecodeFile(): Decode barcodes from a specified image file.
   • DecodeFileInMemory(): Decode barcodes from an image file in memory.
   • DecodeBuffer(): Decode barcodes from raw buffer.

8. Get the decoding results.

    TextResultArray *paryResult = NULL;
    DBR_GetAllTextResults(reader, &paryResult);
   
    if (paryResult->resultsCount == 0)
    {
      printf("No barcode found.\n");
      DBR_FreeTextResults(&paryResult);
      return -1;
    }
   
    printf("Thread id: %d. Total barcode(s) found: %d. Time cost: %d ms\n\n", thread_id, paryResult->resultsCount, timecost);
   
    for (int index = 0; index < paryResult->resultsCount; index++)
    {
      printf("Barcode %d:\n", index + 1);
      printf("    Type: %s\n", paryResult->results[index]->barcodeFormatString);
      printf("    Text: %s\n", paryResult->results[index]->barcodeText);
    }
   
    DBR_FreeTextResults(&paryResult);
   
    DBR_DestroyInstance(reader);
   

9. Build the project and run the barcode and QR code reader in terminal.

    cmake --build . --config Release
    ./BarcodeReader ../images/AllSupportedBarcodeTypes.png 
   

   

Source Code

https://github.com/yushulx/cmake-cpp-barcode-qrcode-mrz