Mac installs Java OpencV dependencies and is configured for use on IntelliJ

Recently, when applying for a driver’s license, I took a lot of photoshopped photos by myself, thinking of the epidemic. As a result, the elder sister of the city hall measured several photos of P with a ruler and found that either his head was too big, or his clothes and background color were wrong. None of the photos could be used, so I had to start again. So I decided to start a small project that would automatically output a single person’s photo with a solid color background as a standard ID photo.

It’s easy to use Java because the backend is familiar with Java. (in fact, image processing related projects in c++ should be more convenient to write) that first to configure the local environment with Java +opencv, mainly is to download and install opencv Java package and then configure to intellij. Here are the steps:

  1. The command tool must be installed on the Mac
xcode-select --install
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  1. Install Ant, you must install Ant (I skipped using Maven and didn’t generate the required Java folder)
brew install ant
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  1. Next you need to run Brew Edit OpencV to modify the default configuration of opnecv by changing -dbuild_opencv_java =OFF to -dbuild_opencv_java =ON to ensure that the required JAR files are generated later.

  2. Install OpencV and run Brew Scandisk –build-from-source OpencV if you didn’t have the JAR file installed previously.

brew install --build-from-source opencv
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  1. After the installation is successful, the/ usr/local/Cellar/opencv / 4.5.3 _2 / share/Java/opencv4There are two required files:
libopencv_java453.dylib
opencv-453.jar
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6. In Intellij, set the folder path to VM Options

7. Add the following code to load the OpencV module before using the OpencV API

System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
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FAQ:

  1. [no opencv_java453 in java.library.path] is displayed after the configuration is complete. In this case, the JAR file is not found
  2. UnsatisfiedLinkError: ‘long org. Opencv. Imgcodecs. Imgcodecs. Imread_1 (Java. Lang. String)’, the situation is opencv module did not load so I can’t correct link to the corresponding method.