opencv cmake android,通过Android Studio上的CMake将OpenCV添加到Native C代码中

我试图通过Cmake将Opencv包含在我的原生C代码中.我在网上做了一些研究并从网上下载了FindOpenCV.cmake文件并将其添加到我的android项目的app目录中.这也是CMakeLists.txt所在的位置.我使用本教程：https://www.learn2crack.com/2016/03/setup-opencv-sdk-android-studio.html将OpenCV作为模块导入到我的Android Studio项目中,当我运行时：

if(!OpenCVLoader.initDebug()){

System.out.println("Opencv not loaded");

} else {

System.out.println("Opencv loaded");

}

我知道Opencv已经加载了.

但是,因为我正在尝试将OpenCV添加到我的本机代码而不是Java代码中,所以我认为我不能使用它.这是我现在拥有的CMakeLists：

# Sets the minimum version of CMake required to build your native library.

# This ensures that a certain set of CMake features is available to

# your build.

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} FindOpenCV.cmake)

# Specifies a library name, specifies whether the library is STATIC or

# SHARED, and provides relative paths to the source code. You can

# define multiple libraries by adding multiple add.library() commands,

# and CMake builds them for you. When you build your app, Gradle

# automatically packages shared libraries with your APK.

add_library(# Specifies the name of the library.

apriltag

# Sets the library as a shared library.

SHARED

# Provides a relative path to your source file(s).

src/main/apriltag/apriltag.c

src/main/apriltag/apriltag_jni.c

src/main/apriltag/apriltag_quad_thresh.c

src/main/apriltag/common/g2d.c

src/main/apriltag/common/getopt.c

src/main/apriltag/common/homography.c

src/main/apriltag/common/image_f32.c

src/main/apriltag/common/image_u8.c

src/main/apriltag/common/image_u8x3.c

src/main/apriltag/common/matd.c

src/main/apriltag/common/pnm.c

src/main/apriltag/common/string_util.c

src/main/apriltag/common/svd22.c

src/main/apriltag/common/time_util.c

src/main/apriltag/common/unionfind.c

src/main/apriltag/common/workerpool.c

src/main/apriltag/common/zarray.c

src/main/apriltag/common/zhash.c

src/main/apriltag/common/zmaxheap.c

src/main/apriltag/tag16h5.c

src/main/apriltag/tag25h7.c

src/main/apriltag/tag25h9.c

src/main/apriltag/tag36artoolkit.c

src/main/apriltag/tag36h10.c

src/main/apriltag/tag36h11.c

)

STRING(REPLACE "-O0" "-O4" CMAKE_C_FLAGS_DEBUG ${CMAKE_C_FLAGS_DEBUG})

STRING(REPLACE "-O2" "-O4" CMAKE_C_FLAGS_RELEASE ${CMAKE_C_FLAGS_RELEASE})

include_directories(src/main/apriltag/)

include_directories(${OpenCV_INCLUDE_DIRS})

find_package(OpenCV REQUIRED)

find_library(log-lib log)

find_library(jnigraphics-lib jnigraphics)

target_link_libraries(apriltag ${log-lib} ${jnigraphics-lib})

以下是构建gradle时遇到的错误：

By not providing "FindOpenCV.cmake" in CMAKE_MODULE_PATH this project has

asked CMake to find a package configuration file provided by "OpenCV", but

CMake did not find one.

Could not find a package configuration file provided by "OpenCV" with any of

the following names:

OpenCVConfig.cmake

opencv-config.cmake

Add the installation prefix of "OpenCV" to CMAKE_PREFIX_PATH or set

"OpenCV_DIR" to a directory containing one of the above files. If "OpenCV"

provides a separate development package or SDK, be sure it has been

installed.

所以我的问题是：

>我可以使用导入的OpenCV,还是必须下载不同的opencv并将其存储在其他地方？

>我需要在CMakeLists.txt中更改哪些内容才能构建我的gradle？

理想情况下,我想构建并能够添加#include< opencv2 / opencv.hpp>并使用命名空间cv到我的c文件并添加使用opencv函数的函数.

谢谢你的帮助！

解决方法:

更新22日 – 5月18日：添加了缺失的第6步.

更新10月10日 – 17日：新解决方案使用CMake和Android Gradle插件2.3.1将OpenCV正确集成到应用程序中.使用Android Studio 2.3.1进行测试.

更新11月5日至17日：提供了另一种解决方案

有两种方法可以包含OpenCV.

Git / Simpler Way

手动/高级方式

要将OpenCV库包含到Android Studio Project中,最好在项目中创建一个新的库模块,并将OpenCV Android SDK包中的文件移植到其中：

>选择File> New Module创建一个新模块.

>选择“Android Library”,然后输入详细信息：

>图书馆名称：OpenCV

>模块名称：opencv

>包名：org.opencv

>创建新模块后,将path_to_opencv_sdk / sdk / java / src目录的内容复制到path_to_your_project / opencv / src / main / java中.

>在main下,创建以下直接路径：aidl / org / opencv / engine并将main / java / org / opencv / engine / OpenCVEngineInterface.aidl移入其中.

>将path_to_opencv_sdk / sdk / java / res的内容复制到path_to_your_project / opencv / src / main / res.

>在path_to_your_project / opencv / src /中创建sdk文件夹,并将path_to_opencv_sdk / sdk / native文件夹复制到其中.

>在opencv模块中,创建CMakeLists.txt文件并按以下顺序添加以下行：

cmake_minimum_required(VERSION 3.4.1)

set(OpenCV_DIR "src/sdk/native/jni")

find_package(OpenCV REQUIRED)

message(STATUS "OpenCV libraries: ${OpenCV_LIBS}")

include_directories(${OpenCV_INCLUDE_DIRS})

>在opencv模块中,编辑build.gradle文件：

...

android {

...

defaultConfig {

minSdkVersion 8

targetSdkVersion 25

versionCode 3200

versionName "3.2.0"

...

externalNativeBuild {

cmake {

cppFlags "-frtti -fexceptions"

}

}

}

buildTypes {

...

}

externalNativeBuild {

cmake {

path "CMakeLists.txt"

}

}

sourceSets {

main {

jni.srcDirs = [jni.srcDirs, 'src/sdk/native/jni/include']

jniLibs.srcDirs = [jniLibs.srcDirs, 'src/sdk/native/3rdparty/libs', 'src/sdk/native/libs']

}

}

}

...

>在应用程序(应用程序模块,可能是另一个名称)模块中,创建/编辑CMakeLists.txt文件并按以下顺序添加以下行(请注意设置为OpenCV_DIR的不同路径)：

set(OpenCV_DIR "../opencv/src/sdk/native/jni")

find_package(OpenCV REQUIRED)

message(STATUS "OpenCV libraries: ${OpenCV_LIBS}")

target_link_libraries(YOUR_TARGET_LIB ${OpenCV_LIBS})

>在应用程序(应用程序模块,可能是另一个名称)模块中,编辑build.gradle文件：

...

android {

...

defaultConfig {

...

externalNativeBuild {

cmake {

cppFlags "-frtti -fexceptions"

}

}

buildTypes {

...

}

externalNativeBuild {

cmake {

path "CMakeLists.txt"

}

}

}

dependencies {

...

compile project(':opencv')

}

>执行gradle同步,现在包含OpenCV本机库,头文件和Java包装器类.

当构建项目并启动apk时,您可以在path_to_project / path_to_app_module / build / output /下检查打包的apk(将apk拖到Android Studio的文本编辑器选项卡上)

您应该在每个abi体系结构文件夹下看到libopencv_java3.so.

在java类中初始化OpenCV SDK：

public class MyClass {

static {

if (BuildConfig.DEBUG) {

OpenCVLoader.initDebug();

}

}

...

}

您应该在logcat消息中看到指定已加载OpenCV(第一个错误是正常的)：

05-10 10:42:31.451 D/OpenCV/StaticHelper: Trying to get library list

05-10 10:42:31.452 E/OpenCV/StaticHelper: OpenCV error: Cannot load info library for OpenCV

05-10 10:42:31.452 D/OpenCV/StaticHelper: Library list: ""

05-10 10:42:31.452 D/OpenCV/StaticHelper: First attempt to load libs

05-10 10:42:31.452 D/OpenCV/StaticHelper: Trying to init OpenCV libs

05-10 10:42:31.452 D/OpenCV/StaticHelper: Trying to load library opencv_java3

05-10 10:42:32.031 D/OpenCV/StaticHelper: Library opencv_java3 loaded

05-10 10:42:32.031 D/OpenCV/StaticHelper: First attempt to load libs is OK

05-10 10:42:32.045 I/OpenCV/StaticHelper: General configuration for OpenCV 3.2.0 =====================================

05-10 10:42:32.045 I/OpenCV/StaticHelper: Version control: 3.2.0

05-10 10:42:32.045 I/OpenCV/StaticHelper: Platform:

05-10 10:42:32.045 I/OpenCV/StaticHelper: Timestamp: 2016-12-23T13:04:49Z

05-10 10:42:32.045 I/OpenCV/StaticHelper: Host: Linux 4.8.0-25-generic x86_64

05-10 10:42:32.045 I/OpenCV/StaticHelper: Target: Linux 1 x86_64

05-10 10:42:32.045 I/OpenCV/StaticHelper: CMake: 2.8.12.2

05-10 10:42:32.045 I/OpenCV/StaticHelper: CMake generator: Ninja

05-10 10:42:32.045 I/OpenCV/StaticHelper: CMake build tool: /usr/bin/ninja

05-10 10:42:32.045 I/OpenCV/StaticHelper: Configuration: Release

05-10 10:42:32.045 I/OpenCV/StaticHelper: C/C++:

05-10 10:42:32.045 I/OpenCV/StaticHelper: Built as dynamic libs?: NO

05-10 10:42:32.045 I/OpenCV/StaticHelper: C++ Compiler: /usr/bin/ccache /opt/android/android-ndk-r10e/toolchains/x86_64-4.9/prebuilt/linux-x86_64/bin/x86_64-linux-android-g++ (ver 4.9)

标签：android,opencv,cmake,java-native-interface

来源： https://codeday.me/bug/20190713/1453137.html