如何在Android中引入OpenCV
本篇文章为大家展示了如何在Android中引入OpenCV，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。
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首先，找到或新建jniLibs文件夹，然后将依赖的动态库和静态库（路径为OpenCV-android-sdk\sdk\native\libs）拷贝到\src\main\jniLibs下面。
然后，找到cpp文件夹。将include文件夹（路径OpenCV-android-sdk\sdk\native\jni\include）拷贝到cpp（路径\app\src\main\cpp）文件夹里。
接着，我们需要引入c++的相关支持。在module的build.gradle里面加入：
externalNativeBuild {
cmake {
//arguments '-DANDROID_TOOLCHAIN=clang', '-DANDROID_STL=gnustl_static'
cppFlags "-std=c++11","-frtti", "-fexceptions"
}
}
ndk{
abiFilters 'armeabi-v7a'
}最后，我们需要在CMakeLists.txt中，加入opencv相关的声明。由于配置比较复杂，在此直接将demo的CMakeLists.txt的内容贴到这里。
# 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)
# 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 them for you.
# Gradle automatically packages shared libraries with your APK.
set(CMAKE_VERBOSE_MAKEFILE on)
set(libs "${CMAKE_SOURCE_DIR}/src/main/jniLibs")
include_directories(${CMAKE_SOURCE_DIR}/src/main/cpp/include)
add_library(libopencv_java3 SHARED IMPORTED )
set_target_properties(libopencv_java3 PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_java3.so")
add_library(libopencv_calib3d STATIC IMPORTED )
set_target_properties(libopencv_calib3d PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_calib3d.a")
add_library(libopencv_core STATIC IMPORTED )
set_target_properties(libopencv_core PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_core.a")
add_library(libopencv_features2d STATIC IMPORTED )
set_target_properties(libopencv_features2d PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_features2d.a")
add_library(libopencv_flann STATIC IMPORTED )
set_target_properties(libopencv_flann PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_flann.a")
add_library(libopencv_highgui STATIC IMPORTED )
set_target_properties(libopencv_highgui PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_highgui.a")
add_library(libopencv_imgcodecs STATIC IMPORTED )
set_target_properties(libopencv_imgcodecs PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_imgcodecs.a")
add_library(libopencv_imgproc STATIC IMPORTED )
set_target_properties(libopencv_imgproc PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_imgproc.a")
add_library(libopencv_ml STATIC IMPORTED )
set_target_properties(libopencv_ml PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_ml.a")
add_library(libopencv_objdetect STATIC IMPORTED )
set_target_properties(libopencv_objdetect PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_objdetect.a")
add_library(libopencv_photo STATIC IMPORTED )
set_target_properties(libopencv_photo PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_photo.a")
add_library(libopencv_shape STATIC IMPORTED )
set_target_properties(libopencv_shape PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_shape.a")
add_library(libopencv_stitching STATIC IMPORTED )
set_target_properties(libopencv_stitching PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_stitching.a")
add_library(libopencv_superres STATIC IMPORTED )
set_target_properties(libopencv_superres PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_superres.a")
add_library(libopencv_video STATIC IMPORTED )
set_target_properties(libopencv_video PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_video.a")
add_library(libopencv_videoio STATIC IMPORTED )
set_target_properties(libopencv_videoio PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_videoio.a")
add_library(libopencv_videostab STATIC IMPORTED )
set_target_properties(libopencv_videostab PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_videostab.a")
add_library(libopencv_ts STATIC IMPORTED )
set_target_properties(libopencv_ts PROPERTIES
IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_ts.a")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11 -fexceptions -frtti")
#include_directories(D:/Projects/Android/CLMAndroid/OpenCV-android-sdk/sdk/native/jni/include )
#set(OpenCV_DIR D:/Projects/Android/CLMAndroid/OpenCV-android-sdk/sdk/native/jni)
#find_package(OpenCV REQUIRED)
#target_link_libraries(${OpenCV_LIBS})
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).
src/main/cpp/native-lib.cpp )
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries 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 this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib android log
libopencv_java3 libopencv_calib3d libopencv_core libopencv_features2d libopencv_flann libopencv_highgui libopencv_imgcodecs
libopencv_imgproc libopencv_ml libopencv_objdetect libopencv_photo libopencv_shape libopencv_stitching libopencv_superres
libopencv_video libopencv_videoio libopencv_videostab
# Links the target library to the log library
# included in the NDK.
${log-lib} )这样配置之后，我们就可以在cpp中，直接使用OpenCV库了。在此贴一个简单的均值滤波：
#include#include #include #include #include #include #include"opencv2/imgproc/imgproc.hpp" using namespace cv; using namespace std; #define MAKE_ARGB(a, r, g, b) ((a&0xff)<<24) | ((r&0xff)<<16) | ((g&0xff)<<8) | (b&0xff) #define MAKE_RGB565(r, g, b) ((((r) >> 3) << 11) | (((g) >> 2) << 5) | ((b) >> 3)) extern "C" { JNIEXPORT jintArray JNICALL Java_com_live_longsiyang_opencvdemo_OpenCVNativeManager_getBlurImage(JNIEnv *env, jobject thiz, jintArray pixels_, jint w, jint h) { int colorType = CV_8UC4; jint *pixels = env->GetIntArrayElements(pixels_, NULL); Mat imgMat(h, w, colorType, pixels); Mat out(h, w, colorType); blur(imgMat, out, Size(20, 20)); env->ReleaseIntArrayElements(pixels_, pixels, 0); int *outIntImage = new int[w * h]; for (int i = 0; i < w * h; i++) { int a, r, g, b; for (int j = 0; j < 4; j++) { a = out.data[i * 4 + 3]; r = out.data[i * 4 + 2]; g = out.data[i * 4 + 1]; b = out.data[i * 4 + 0]; outIntImage[i] = (int) out.data[i * 4 + j]; } outIntImage[i] = MAKE_ARGB(a,r,g,b); } jintArray result = env->NewIntArray(w * h); env->SetIntArrayRegion(result, 0, w * h, outIntImage); return result; } }
这样我们就能看到一个基本的模糊效果的demo。
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
static {
System.loadLibrary("native-lib");
}
ImageView mIvTest;
Button mBtnTest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mIvTest = (ImageView) findViewById(R.id.img_test);
mIvTest.setImageResource(R.drawable.beauty_steward_course_video_thumb_icon);
mBtnTest = (Button) findViewById(R.id.btn_test);
mBtnTest.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Bitmap srcBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.beauty_steward_course_video_thumb_icon);
int w = srcBitmap.getWidth();
int h = srcBitmap.getHeight();
int[] pixels = new int[w*h];
srcBitmap.getPixels(pixels,0,w,0,0,w,h);
int[] outPixels = OpenCVNativeManager.getBlurImage(pixels ,w,h);
Bitmap destBitmap = Bitmap.createBitmap(w,h, Bitmap.Config.ARGB_8888);
destBitmap.setPixels(outPixels,0,w,0,0,w,h);
mIvTest.setImageBitmap(destBitmap);
}
});
findViewById(R.id.btn_reset).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mIvTest.setImageResource(R.drawable.beauty_steward_course_video_thumb_icon);
}
});
}
}
导出.so
在build中找到这个so，这就是我们需要的文件。此外，由于我们使用了opencv相关的库，我们还需要将opencv的相关文件复制出来。将其导入我们需要的工程。
导入之后，我们只需要在module的build.gradle里面加入:
android {
...
sourceSets {
main {
jniLibs.srcDirs = ['src/main/jniLibs']
aidl.srcDirs = ['src/main/aidl']
}
}
}之后，我们就可以直接调用
System.loadLibrary("native-lib");上述内容就是如何在Android中引入OpenCV，你们学到知识或技能了吗？如果还想学到更多技能或者丰富自己的知识储备，欢迎关注创新互联行业资讯频道。
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