OpenCV(Open Source Computer Vision Library)

下载OpenCV4Android SDK

在Android平台以来OpenCV进行开发，需要下载OpenCV For Android的SDK，下载地址如下：

https://www.docs.opencv.org/2.4/doc/tutorials/introduction/android_binary_package/O4A_SDK.html#get-the-opencv4android-sdk

下载完成后解压，得到的文件结构如下：

Android OpenCV环境搭建(Cmake)

doc文件夹下是OpenCV SDK相关的一些参考文档
samples文件夹下是OpenCV 的一些例子
sdk/java文件夹下是OpenCV的java依赖Module，需要配合OpenCVManager这个apk文件使用
sdk/native文件夹下是OpenCV的一些native头文件或者源文件

引入OpenCV4Android Module

在Android Studio中新建Android项目OpenCV01,随后添加sdk_directory/sdk/java该路径作为OpenCV01的一个Module，步骤截图如下：
首先选择File->New module

Android OpenCV环境搭建(Cmake)

在该页面选择import eclipse ADT project

Android OpenCV环境搭建(Cmake)

在上面页面选择OpenCV SDK的sdk/java路径，随后点击Finish，等待项目构建完成。
项目构建完成后，将新加入的OpenCV Module添加为当前项目Module的依赖Module，完成绑定关系，如下：

Android OpenCV环境搭建(Cmake)

随后点击左下角加号，选择Module dependency

Android OpenCV环境搭建(Cmake)

选择openCVLibrary点击确定，等待项目构建完成即可。以上步骤就完成了OpenCV Module的引入过程，如果不需要是用C++做OpenCV相关开发，到这里就可以畅游OpenCV海洋了。

添加OpenCV native支持

由于Android Studio2.2以后，NDK build推荐用cmake构建，所以我们这里来简单介绍下是用cmake构建OpenCV native开发环境的基本过程，除了上面引入OpenCV Module[**注意新建的项目要support c++**］外，我们还需要做如下操作：
首先在app/src/main目录下创建jniLibs文件夹，并将sdk/native/libs下面的所有文件拷入：

Android OpenCV环境搭建(Cmake)

随后修改build.gradle文件，添加如下内容：

sourceSets {    main {        jniLibs.srcDirs = ['src/main/jniLibs']    }}    externalNativeBuild {        cmake {            cppFlags "-frtti -fexceptions"            abiFilters 'x86', 'x86_64', 'armeabi', 'armeabi-v7a', 'arm64-v8a', 'mips', 'mips64'        }    }

随后修改cmakelists.txt如下：

# For more information about using CMake with Android Studio, read the# documentation: https://d.android.com/studio/projects/add-native-code.html# Sets the minimum version of CMake required to build the native library.cmake_minimum_required(VERSION 3.4.1)include_directories(/Volumes/Android_Code/OpenCVProject/OpenCV-android-sdk/sdk/native/jni/include)add_library( lib_opencv SHARED IMPORTED )set_target_properties(lib_opencv PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/src/main/jniLibs/${ANDROID_ABI}/libopencv_java.so)# Creates and names a library, sets it as either STATIC# or SHARED, and provides the relative paths to its source code.# You can define multiple libraries, and CMake builds it for you.# Gradle automatically packages shared libraries with your APK.add_library( # Sets the name of the library.             native-lib             # Sets the library as a shared library.             SHARED             # Provides a relative path to your source file(s).             # Associated headers in the same location as their source             # file are automatically included.             src/main/cpp/native-lib.cpp )# Searches for a specified prebuilt library and stores the path as a# variable. Because system libraries are included in the search path by# default, you only need to specify the name of the public NDK library# you want to add. CMake verifies that the library exists before# completing its build.find_library( # Sets the name of the path variable.              log-lib              # Specifies the name of the NDK library that              # you want CMake to locate.              log )# Specifies libraries CMake should link to your target library. You# can link multiple libraries, such as libraries you define in the# build script, prebuilt third-party libraries, or system libraries.target_link_libraries( # Specifies the target library.                       native-lib                       # OpenCV lib                       lib_opencv                       # Links the target library to the log library                       # included in the NDK.                       ${log-lib} )

修改后重新rebuild项目就好。

https://github.com/tuozhaobing/CsdnDemoCode/tree/master/OpenCV02

https://github.com/leadrien/opencv\_native\_androidstudio

由于MediaCodec系列第四篇还没准备好，所以先给大家推一篇OpenCV环境搭建的博，望见谅。

Android OpenCV环境搭建(Cmake)