OpenCV Bindings for Dart: A Comprehensive Guide

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OpenCV Bindings for Dart: A Comprehensive Guide

opencv_dart, an open-source project, provides extensive bindings for OpenCV (Open Source Computer Vision Library) in Dart, empowering developers to leverage the vast functionalities of OpenCV in their applications. This article delves into the specifics of opencv_dart, including its features, usage, compilation instructions, and a detailed overview of supported modules.

Features and Highlights

  • Bindings for a wide range of OpenCV modules, including Core, Calib3D, DNN, Features2D, HighGUI, Imgcodecs, Imgproc, ML, Objdetect, Photo, Stitching, SVD, Video, VideoIO, and more.
  • Comprehensive support for various platforms, including Android, iOS, Linux, Windows, and macOS.
  • Prebuilt binary libraries for convenient integration.
  • Extensive documentation and examples to facilitate easy adoption.

Usage

For Pure Dart:

import 'package:opencv_dart/opencv_dart.dart' as cv;

void main() {
  final img = cv.imread("test/images/lenna.png", flags: cv.IMREAD_COLOR);
  final gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY);
  print("$, $");
  cv.imwrite("test_cvtcolor.png", gray);
}

For Flutter:

Refer to the example provided in the opencv_dart repository.

Compilation Instructions

Prerequisites:

  • A compatible compiler (Visual Studio 2019 or later for Windows, proper toolchain for Linux/macOS)
  • Conan package manager

Steps:

  1. Clone the opencv_dart repository.
  2. Navigate to the cloned directory.
  3. Install Conan and detect your profile.
  4. Compile using Conan:
    • For Windows: conan build . -b missing -s compiler.cppstd=20
    • For Linux/macOS: conan build . -b missing
    • For Android: conan build . -b missing -pr:h profiles/android-<arch> -c tools.android:ndk_path="<ABSOLUTE path for ndk>"
    • For iOS: echo "tools.cmake.cmaketoolchain:user_toolchain=[\"pwd/profiles/ios.toolchain.cmake\"]" >> profiles/ios-<arch>" && conan build . -b missing -pr:h profiles/ios-<arch>

Supported Modules

Core Modules:

  • Core: Core OpenCV functionality.
  • Calib3D: Camera calibration and 3D reconstruction.
  • DNN: Deep neural network module.
  • Features2D: Feature detection and matching.
  • HighGUI: High-level GUI for image and video display.
  • Imgcodecs: Image codecs for reading and writing various image formats.
  • Imgproc: Image processing and transformation.
  • ML: Machine learning algorithms.
  • Objdetect: Object detection and recognition.
  • Photo: Image enhancement and manipulation.
  • Stitching: Image stitching for creating panoramas.
  • SVD: Singular Value Decomposition.
  • Video: Video capture, processing, and analysis.
  • VideoIO: Video input/output.

Contrib Modules:

  • Aruco: Augmented reality marker detection.
  • Img_hash: Image hashing.
  • Wechat_qrcode: WeChat QR code detection.

Additional Resources

Conclusion

opencv_dart offers a powerful and flexible solution for integrating OpenCV functionalities into Dart applications. With its comprehensive module support, platform compatibility, and ease of use, opencv_dart empowers developers to leverage the cutting-edge capabilities of OpenCV in a wide range of domains, including computer vision, image processing, and artificial intelligence.

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