前文:
Ubuntu 編譯 OpenCV SDK for Android + Linux
OpenCV 4.10.0 移植
概述
?????在移動應用開發領域，Android平臺與OpenCV庫的結合為開發者提供了強大的圖像處理和計算機視覺能力。OpenCV(Open Source Computer Vision Library)是一個開源的計算機視覺和機器學習軟件庫，而Android則是全球最流行的移動操作系統之一。兩者的結合使得開發者能夠在移動設備上實現復雜的圖像處理功能，從簡單的濾鏡應用到高級的物體識別和增強現實體驗。
?????Android平臺為OpenCV提供了廣泛的硬件支持和用戶基礎，而OpenCV則為Android開發者提供了豐富的圖像處理算法和工具。這種協同關系使得開發者能夠輕松地將計算機視覺技術集成到移動應用中，無需從零開始實現復雜的圖像處理算法。無論是人臉檢測、二維碼識別、圖像增強還是實時視頻處理，Android與OpenCV的結合都為這些功能提供了可靠的技術基礎。
?????隨著移動設備計算能力的不斷提升，Android+OpenCV的組合正在推動移動端計算機視覺應用的快速發展，為醫療、安防、零售、娛樂等多個行業帶來了創新的解決方案.
針對Ubuntu 編譯 OpenCV SDK for Android + Linux一文:
- 彌補缺少java文件輸出
- 使用Gradle
- 增加示例測試
環境
| 屬性 | 值 |
|---|---|
| OpenJDK | 11 |
| abi | armeabi-v7a |
| Android Gradle Plugin Version | 4.2.2 |
| Gradle Version | 6.7.1 |
| cmake | 3.16.3 |
| NDK | 22.0.7026061 |
編譯腳本:
注: OpenCV的下載解壓, 前文已有, 不在贅述.
構建的方法有兩種:
- 使用python腳本
- 使用傳統的make
export ANDROID_HOME=/home/xxxxx/Android/Sdk/
export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools
export ANDROID_NDK_HOME=$ANDROID_HOME/ndk/22.0.7026061
export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
TOOLCHAINS=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmakewithPython=0output_dir=build-android
if [ ! -d $output_dir ]; thenmkdir $output_dir
fifor arg in $@; doif [ $arg == "clean" ]; thenecho "build with clean"rm -rf $output_dir/*elif [ $arg == "python" ]; thenecho "build via python"withPython=1;fidone## -------------------- ##
cd $output_direcho "START Configure..."
echo "build via python is $withPython"## OK
if [ $withPython == "1" ]; thenpython ../platforms/android/build_sdk.py \--config=../platforms/android/ndk-22.config.py \--ndk_path=$ANDROID_NDK_HOME \--sdk_path=$ANDROID_HOME \--no_ccache \--no_samples_build \. \..
elseabis="armeabi-v7a arm64-v8a"for abi in $abis; doecho "build ABI:$abi"cmake \-D ANDROID_SDK=$ANDROID_HOME \-D ANDROID_NDK=$ANDROID_NDK_HOME \-D CMAKE_ANDROID_NDK=$ANDROID_NDK_HOME \-D CMAKE_TOOLCHAIN_FILE=$TOOLCHAINS \-D ANDROID_TOOLCHAIN='clang' \-D ANDROID_ABI=$abi \-D ANDROID_STL='c++_shared' \-D ANDROID_PLATFORM_ID='2' \-D ANDROID_GRADLE_PLUGIN_VERSION='4.1.2' \-D GRADLE_VERSION='6.5' \-D KOTLIN_PLUGIN_VERSION='1.5.10' \-D BUILD_ANDROID_EXAMPLES='OFF' \-D INSTALL_ANDROID_EXAMPLES='OFF' \-D BUILD_DOCS='OFF' \-D WITH_OPENCL='OFF' \-D WITH_CUDA=OFF \-D WITH_MATLAB=OFF \-D BUILD_EXAMPLES=OFF \-D BUILD_PERF_TESTS=OFF \-D BUILD_TESTS=OFF \-D WITH_TBB='OFF' \-D INSTALL_TESTS='OFF' \-D INSTALL_CREATE_DISTRIB='OFF' \-D BUILD_KOTLIN_EXTENSIONS='OFF' \..#ninja opencv_modulesmake -j12make installdone
fiecho "--END--"## reference
# OpenJDK 11
# -D BUILD_ANDROID_PROJECTS=ON : 才能編譯出JAVA# -D BUILD_SHARED_LIBS=ON 編譯出so庫# CMake Error at /usr/share/cmake-3.22/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
# Could NOT find OpenCV (missing: opencv_java) (found version "4.10.0")
# Call Stack (most recent call first):
# /usr/share/cmake-3.22/Modules/FindPackageHandleStandardArgs.cmake:594 (_FPHSA_FAILURE_MESSAGE)
# /media/xxxxx/codes/opencv-4.10.0/build-android/OpenCVConfig.cmake:367 (find_package_handle_standard_args)
# CMakeLists.txt:15 (find_package)# 好戲上演：為Android項目編譯OpenCV 4.1.0，可按需編譯模塊，大大減少空間。
# https://juejin.cn/post/7225511164125610021# https://zj-image-processing.readthedocs.io/zh-cn/latest/opencv/install-configure/[OpenCV_Contrib-4.0.1]%E7%BC%96%E8%AF%91OpenCV4Android/
編譯輸出:
opencv-4.10.0/build-android/install/sdk$ ll
total 40
drwxrwxr-x 8 xxxxx xxxxx 4096 7月 8 15:32 ./
drwxrwxr-x 4 xxxxx xxxxx 4096 7月 8 13:47 ../
drwxrwxr-x 7 xxxxx xxxxx 4096 7月 8 15:32 build/
-rw-r--r-- 1 xxxxx xxxxx 5628 7月 8 15:27 build.gradle
drwxrwxr-x 3 xxxxx xxxxx 4096 7月 8 15:32 .cxx/
drwxrwxr-x 5 xxxxx xxxxx 4096 7月 8 13:47 etc/
drwxrwxr-x 4 xxxxx xxxxx 4096 7月 8 14:58 java/
drwxrwxr-x 2 xxxxx xxxxx 4096 7月 8 14:58 libcxx_helper/
drwxrwxr-x 6 xxxxx xxxxx 4096 7月 8 13:47 native/導入到AndroidStudio
- settings.gradle 增加OpenCV模塊
include ':opencv-4.10'
project(':opencv-4.10').projectDir = new File("opencv-4.10.0/build-android/install/sdk")
- app模塊增加依賴
build.gradle
apply plugin: 'com.android.application'
android {defaultConfig {//省略app信息externalNativeBuild{ndk{abiFilters 'armeabi-v7a'}}}
}
dependencies {implementation project(':opencv-4.10')
}
- 導入OpenCV出錯, 參照下文注釋部分配置:
// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.//
// Notes about integration OpenCV into existed Android Studio application project are below (application 'app' module should exist).
//
// This file is located in <OpenCV-android-sdk>/sdk directory (near 'etc', 'java', 'native' subdirectories)
//
// Add module into Android Studio application project:
//
// - Android Studio way:
// (will copy almost all OpenCV Android SDK into your project, ~200Mb)
//
// Import module: Menu -> "File" -> "New" -> "Module" -> "Import Gradle project":
// Source directory: select this "sdk" directory
// Module name: ":opencv"
//
// - or attach library module from OpenCV Android SDK
// (without copying into application project directory, allow to share the same module between projects)
//
// Edit "settings.gradle" and add these lines:
//
// def opencvsdk='<path_to_opencv_android_sdk_rootdir>'
// // You can put declaration above into gradle.properties file instead (including file in HOME directory),
// // but without 'def' and apostrophe symbols ('): opencvsdk=<path_to_opencv_android_sdk_rootdir>
// include ':opencv'
// project(':opencv').projectDir = new File(opencvsdk + '/sdk')
//
//
//
// Add dependency into application module:
//
// - Android Studio way:
// "Open Module Settings" (F4) -> "Dependencies" tab
//
// - or add "project(':opencv')" dependency into app/build.gradle:
//
// dependencies {
// implementation fileTree(dir: 'libs', include: ['*.jar'])
// ...
// implementation project(':opencv')
// }
//
//
//
// Load OpenCV native library before using:
//
// - avoid using of "OpenCVLoader.initAsync()" approach - it is deprecated
// It may load library with different version (from OpenCV Android Manager, which is installed separatelly on device)
//
// - use "System.loadLibrary("opencv_java4")" or "OpenCVLoader.initDebug()"
// TODO: Add accurate API to load OpenCV native library
//
//
//
// Native C++ support (necessary to use OpenCV in native code of application only):
//
// - Use find_package() in app/CMakeLists.txt:
//
// find_package(OpenCV 4.10 REQUIRED java)
// ...
// target_link_libraries(native-lib ${OpenCV_LIBRARIES})
//
// - Add "OpenCV_DIR" and enable C++ exceptions/RTTI support via app/build.gradle
// Documentation about CMake options: https://developer.android.com/ndk/guides/cmake.html
//
// defaultConfig {
// ...
// externalNativeBuild {
// cmake {
// cppFlags "-std=c++11 -frtti -fexceptions"
// arguments "-DOpenCV_DIR=" + opencvsdk + "/sdk/native/jni" // , "-DANDROID_ARM_NEON=TRUE"
// }
// }
// }
//
// - (optional) Limit/filter ABIs to build ('android' scope of 'app/build.gradle'):
// Useful information: https://developer.android.com/studio/build/gradle-tips.html (Configure separate APKs per ABI)
//
// splits {
// abi {
// enable true
// universalApk false
// reset()
// include 'armeabi-v7a' // , 'x86', 'x86_64', 'arm64-v8a'
// }
// }
//plugins {id 'com.android.library' // or 'com.android.application' if this is an app module
}//apply plugin: 'maven-publish'def openCVersionName = "4.10.0"
def openCVersionCode = ((4 * 100 + 10) * 100 + 0) * 10 + 0println "OpenCV: " +openCVersionName + " " + project.buildscript.sourceFileandroid {compileSdkVersion 31defaultConfig {minSdkVersion 21targetSdkVersion 31versionCode openCVersionCodeversionName openCVersionNameexternalNativeBuild {cmake {arguments "-DANDROID_STL=c++_shared"targets "opencv_jni_shared"}}}compileOptions {sourceCompatibility JavaVersion.VERSION_1_8targetCompatibility JavaVersion.VERSION_1_8}buildTypes {debug {packagingOptions {doNotStrip '**/*.so' // controlled by OpenCV CMake scripts}}release {packagingOptions {doNotStrip '**/*.so' // controlled by OpenCV CMake scripts}minifyEnabled falseproguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'}}//buildFeatures {// prefabPublishing true// buildConfig true//}//prefab {// opencv_jni_shared {// headers "native/jni/include"// }//}sourceSets {main {jniLibs.srcDirs = ['native/libs']java.srcDirs = ['java/src']res.srcDirs = ['java/res']manifest.srcFile 'java/AndroidManifest.xml'}}//publishing {// singleVariant('release') {// withSourcesJar()// withJavadocJar()// }//}externalNativeBuild {cmake {path (project.projectDir.toString() + '/libcxx_helper/CMakeLists.txt')}}
}//publishing {
// publications {
// release(MavenPublication) {
// groupId = 'org.opencv'
// artifactId = 'opencv'
// version = '4.10.0'
//
// afterEvaluate {
// from components.release
// }
// }
// }
// repositories {
// maven {
// name = 'myrepo'
// url = "${project.buildDir}/repo"
// }
// }
//}
//
//dependencies {
//}- app 調用:
public Mat onCameraFrame(Mat inputFrame) {Mat frame = inputFrame;Mat gray = new Mat();Mat edges = new Mat();List<MatOfPoint> contours = new ArrayList<>();// Convert to grayscaleImgproc.cvtColor(frame, gray, Imgproc.COLOR_RGBA2GRAY);// Apply Canny edge detectionImgproc.Canny(gray, edges, 100, 200);// Find contoursImgproc.findContours(edges, contours, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);// Draw contours in redScalar redColor = new Scalar(255, 0, 0, 255); // RGBA: RedImgproc.drawContours(frame, contours, -1, redColor, 2);// Release temporary Mats//gray.release();//edges.release();return frame;}
運行效果:
一些問題
-
如果LOG找不到libc++_shared.so
22.0.7026061/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++_shared.so
把這個文件拷貝到app的目錄下:
src/main/jniLibs/armeabi-v7a/libc++_shared.so
完整代碼
OpenCV 4.10.0 移植 - Android 參考調用示例代碼
參考
[Ubuntu 16.04][Anaconda3][OpenCV_Contrib 4.0.1]編譯OpenCV4Android
Ubuntu 編譯 OpenCV SDK for Android + Linux
OpenCV 4.10.0 移植
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