[安卓开发笔记一]Android开发配置opencv环境超详细教程



前期准备

1
上opencv官网，下载opencv
for android

2
安装 Android studio

方法一（使用C++实现底层算法再利用jni传递使用）：

开始配置

1.安装Android
NDK

新建项目，建完后可通过Android studio下载Android
NDK环境

一般是没有Android NDK的，勾上后点Apply，然后等它下载，安装

PS：需要翻墙，不知道如何翻墙的，参考如下网址

http://blog.softweek.net/article/google-hosts

2
添加opencv native包

将opencv官网上下载好的opencv
forAndroid 中的native文件夹，拷贝到建好的工程根目录下，如图

拷贝前：

拷贝后：

3
配置编译环境

编辑gradle.properties文件，增加下面的属性使用旧版的ndk功能（不添加会使用实验性的ndk构建工具）

android.useDeprecatedNdk=true

在local.properties文件中配置ndk目录

ndk.dir=D\:\\Android\\sdk\\ndk-bundle

sdk.dir=D\:\\Android\\sdk

（如果是通过Android studio
来安装的Android NDK
这一步可以不用，因为Android studio安装NDK时给你自动配置好了）

编辑build.gradle，在android节点中增加下面的代码

sourceSets.main.jni.srcDirs = []

//禁止自带的ndk功能

sourceSets.main.jniLibs.srcDirs = ['src/main/libs','src/main/jniLibs']

//重定向so目录为src/main/libs和src/main/jniLibs，原来为src/main/jniLibs

task ndkBuild(type: Exec, description: 'Compile JNI source with NDK') {

Properties properties = new Properties()

properties.load(project.rootProject.file('local.properties').newDataInputStream())

def ndkDir = properties.getProperty('ndk.dir')

if (org.apache.tools.ant.taskdefs.condition.Os.isFamily(org.apache.tools.ant.taskdefs.condition.Os.FAMILY_WINDOWS)) {

commandLine "$ndkDir/ndk-build.cmd", '-C', file('src/main/jni').absolutePath

} else {

commandLine "$ndkDir/ndk-build", '-C', file('src/main/jni').absolutePath

}

}

tasks.withType(JavaCompile) {

compileTask -> compileTask.dependsOn ndkBuild

}

task ndkClean(type: Exec, description: 'Clean NDK Binaries') {

Properties properties = new Properties()

properties.load(project.rootProject.file('local.properties').newDataInputStream())

def ndkDir = properties.getProperty('ndk.dir')

if (org.apache.tools.ant.taskdefs.condition.Os.isFamily(org.apache.tools.ant.taskdefs.condition.Os.FAMILY_WINDOWS)) {

commandLine "$ndkDir/ndk-build.cmd",'clean', '-C', file('src/main/jni').absolutePath

} else {

commandLine "$ndkDir/ndk-build",'clean', '-C', file('src/main/jni').absolutePath

}

}

clean.dependsOn 'ndkClean'

加入前：

加入后（代码太长截图没截完）：

在main中新建jni目录，并在jni中新建Android.mk和Application.mk

在Android.mk中加入如下代码

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

OpenCV_INSTALL_MODULES := on

OpenCV_CAMERA_MODULES := off

OPENCV_LIB_TYPE :=STATIC

ifeq ("$(wildcard $(OPENCV_MK_PATH))","")

include ..\..\..\..\native\jni\OpenCV.mk

else

include $(OPENCV_MK_PATH)

endif

LOCAL_MODULE := OpenCV

LOCAL_SRC_FILES :=

LOCAL_LDLIBS +=  -lm -llog

include $(BUILD_SHARED_LIBRARY)

在Application.mk中加入如下代码

APP_STL := gnustl_static

APP_CPPFLAGS := -frtti -fexceptions

APP_ABI := armeabi armeabi-v7a

APP_PLATFORM := android-8

这时候，使用gradle构建一下，如果能成功构建出so，说明配置没问题，如下图，点击Android
studio右侧的gradle展开，在app->other中找到ndkbuild(没有就刷新)进行构建

4
实现jni调用

在建项目时自带的java文件所在的文件夹中，新建一个java文件，声明native方法，这里尝试实现灰度化方法，所以命名为gray

使用javah命令生成头文件，利用AS（android
studio）下方的terminal窗口

如图：

这里需要注意，有大坑，不会javah的人尤其注意，这里不能进入刚才新建的java文件所在那个目录进行生成，会出现找不到“XXX”类错误，使用javah命令时，必须进入java目录，即上图中cd进去的那个目录，然后使用

javah -d ../jnicom.example.administrator.tryopencv.OpenCVHelper

其中中间的-d ../jni
是指定输出目录，后面需要生成头文件的java名称一定要写完整，要从com开始写，每一层包含关系都写出来，即写成这样com.example.administrator.tryopencv.OpenCVHelper

这样才没问题，在jni目录中会出现生成的头文件，如上图所示

头文件中内容如下：

然后新建刚才生成的.h对应的cpp文件，注意文件名称和函数名称，一定要一致哦

建好后就在里面写实现函数啦，灰度化图像

//

// Created by Administrator on 2015/12/22.

//

#include "com_example_administrator_tryopencv_OpenCVHelper.h"

#include <stdio.h>

#include <stdlib.h>

#include <opencv2/opencv.hpp>

using namespace cv;

extern "C" {

JNIEXPORT jintArray JNICALL Java_com_example_administrator_tryopencv_OpenCVHelper_gray(JNIEnv *env,jclass obj,jintArray buf,int w,int h);

JNIEXPORT jintArray JNICALL Java_com_example_administrator_tryopencv_OpenCVHelper_gray(JNIEnv *env,jclass obj,jintArray buf,int w,int h)

{

jint *cbuf;

cbuf = env->GetIntArrayElements(buf,JNI_FALSE);

if (NULL == cbuf)

{

return 0;

}

Mat imgData(h,w,CV_8UC4,(unsigned char*) cbuf);

u_char *ptr = imgData.ptr(0);

for (int i = 0; i < w*h; ++i)

{

//图像存储方式为：BGRA

int grayScale = (int)(ptr[4*i+2]*0.299 + ptr[4*i+1]*0.587 + ptr[4*i+0]*0.144 );

ptr[4*i+0] = grayScale;

ptr[4*i+1] = grayScale;

ptr[4*i+2] = grayScale;

}

int size = w * h;

jintArray  result = env->NewIntArray(size);

env->SetIntArrayRegion(result,0,size,cbuf);

env->ReleaseIntArrayElements(buf,cbuf,0);

return result;

}

}

然后在Andorid.mk文件中加入

LOCAL_SRC_FILES :=com_example_administrator_tryopencv_OpenCVHelper.cpp

然后在java主代码中写测试代码调用就行啦

这时布局文件代码

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="com.example.administrator.choosepic.PicActivity">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="choose picture!"

android:id="@+id/title"/>

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="灰度图"

android:id="@+id/GiveFaceButton"

android:layout_below="@+id/title"

android:layout_alignLeft="@+id/GetFaceButton"

android:layout_alignStart="@+id/GetFaceButton"

android:layout_marginTop="71dp" />

<ImageView

android:adjustViewBounds="true"

android:maxHeight="400dp"

android:maxWidth="200dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:scaleType="fitStart"

android:id="@+id/IV01" />

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="原图"

android:id="@+id/GetFaceButton"

android:layout_centerVertical="true"

android:layout_alignParentRight="true"

android:layout_alignParentEnd="true" />

<ImageView

android:adjustViewBounds="true"

android:maxHeight="400dp"

android:maxWidth="200dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:scaleType="fitStart"

android:id="@+id/IV02"

android:layout_below="@id/IV01" />

</RelativeLayout>

这是java文件中的代码

package com.example.administrator.tryopencv;

import android.content.ContentResolver;

import android.content.Intent;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.net.Uri;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.ImageView;

import java.io.FileNotFoundException;

import java.io.InputStream;

public class tryOpenCvActivity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_try_open_cv);

Button GiveFaceButton = (Button)findViewById(R.id.GiveFaceButton);

GiveFaceButton.setOnClickListener(new Button.OnClickListener()

{

public void onClick(View v)

{

Intent myIntent = new Intent();

//开启picture画面Type设置为image*

myIntent.setType("image/*");

//使用Intent.ACTION_GET_CONTENT这个Action

myIntent.setAction(Intent.ACTION_GET_CONTENT);

/*取得相片后返回本画面*/

startActivityForResult(myIntent,1);

}

});

Button GetFaceButton = (Button)findViewById(R.id.GetFaceButton);

GetFaceButton.setOnClickListener(new Button.OnClickListener()

{

public void onClick(View v)

{

Intent myIntent = new Intent();

//开启picture画面Type设置为image*

myIntent.setType("image/*");

//使用Intent.ACTION_GET_CONTENT这个Action

myIntent.setAction(Intent.ACTION_GET_CONTENT);

/*取得相片后返回本画面*/

startActivityForResult(myIntent,2);

}

});

}

protected void onActivityResult(int requestCode,int resultCode,Intent data)

{

switch (requestCode)

{

case 1 :

Uri uri = data.getData();

Log.e("uri",uri.toString());

ContentResolver cr = this.getContentResolver();

try

{

InputStream input = cr.openInputStream(uri);

BitmapFactory.Options options = new BitmapFactory.Options();

options.inJustDecodeBounds = true;

BitmapFactory.decodeStream(input, null, options);

if (options.outWidth > 1024 || options.outHeight > 1024){

options.inSampleSize = Math.max(options.outWidth / 1024, options.outHeight/1024);

}

options.inJustDecodeBounds = false;

Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri), null, options);

/*以下进行灰度化处理*/

int w = bitmap.getWidth();

int h = bitmap.getHeight();

int[] pix = new int[w * h];

bitmap.getPixels(pix, 0, w, 0, 0, w, h);

int[] resultPixels = OpenCVHelper.gray(pix, w, h);

Bitmap result = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);

result.setPixels(resultPixels,0,w,0,0,w,h);

ImageView imageView = (ImageView)findViewById(R.id.IV01);

/*将处理好的灰度图设定到ImageView*/

imageView.setImageBitmap(result);

}

catch(FileNotFoundException e)

{

Log.e("Exception",e.getMessage(),e);

}

break;

case 2:

Uri uri2 = data.getData();

Log.e("uri2",uri2.toString());

ContentResolver cr2 = this.getContentResolver();

try

{

InputStream input = cr2.openInputStream(uri2);

BitmapFactory.Options options = new BitmapFactory.Options();

options.inJustDecodeBounds = true;

BitmapFactory.decodeStream(input, null, options);

if (options.outWidth > 1024 || options.outHeight > 1024){

options.inSampleSize = Math.max(options.outWidth / 1024, options.outHeight/1024);

}

options.inJustDecodeBounds = false;

Bitmap bitmap = BitmapFactory.decodeStream(cr2.openInputStream(uri2), null, options);

ImageView imageView = (ImageView)findViewById(R.id.IV02);

/*将Bitmap设定到ImageView*/

imageView.setImageBitmap(bitmap);

}

catch(FileNotFoundException e)

{

Log.e("Exception",e.getMessage(),e);

}

break;

default:

break;

}

super.onActivityResult(requestCode, resultCode,data);

}

}

然后就可以运行啦

看看效果：

哦了

方法二
（使用opencv封装的jar包，纯java层代码处理）

前期准备和方法一相同，实际上，按照方法一做到“3
配置编译环境”中的编辑Android.mk和Application.mk这一步

这里需要编译出动态库，所以Android会有所不同

其中内容如下：

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

OpenCV_INSTALL_MODULES := on

OpenCV_CAMERA_MODULES := off

OPENCV_LIB_TYPE :=SHARED

ifeq ("$(wildcard $(OPENCV_MK_PATH))","")

include ..\..\..\..\native\jni\OpenCV.mk

else

include $(OPENCV_MK_PATH)

endif

LOCAL_MODULE := OpenCV

LOCAL_SRC_FILES :=

LOCAL_LDLIBS +=  -lm -llog

include $(BUILD_SHARED_LIBRARY)

主要改的这两个地方

OPENCV_LIB_TYPE :=SHARED（静态改动态）

LOCAL_SRC_FILES :=（没有c++底层代码所以这里为空）

然后在项目中加入opencv的jar包，将之前下好的，opencv
for Android sdk中的org文件夹拷贝到main文件夹中

如图：

在main文件夹下新建aidl文件夹

将org/opencv/engine/XXX.aidl文件连同目录一起拷到刚才新建的文件夹中

如图

这里动态编译出的libopencv.so还依赖于libopencv_java3.so文件，这个文件在native/libs中可以找到，一般添加armeabi和armeabi-v7a中的即可，然后在main文件夹中新建jnilibs文件夹，将armeabi和armeabi-v7a中的libopencv_java3.so连同文件夹一起拷贝到jnilibs，还有一个资源文件，将sdk\java\res\values下的attrs.xml拷贝到工程目录res\values目录下，不然camera会有变量不认识

如图：

布局文件：

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="com.example.administrator.tryopencv2.tryOpenCv2Activity">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="choose picture!"

android:id="@+id/title"/>

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="原图"

android:id="@+id/GiveFaceButton"

android:layout_below="@+id/title"

android:layout_alignLeft="@+id/GetFaceButton"

android:layout_alignStart="@+id/GetFaceButton"

android:layout_marginTop="71dp" />

<ImageView

android:adjustViewBounds="true"

android:maxHeight="400dp"

android:maxWidth="200dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:scaleType="fitStart"

android:id="@+id/IV01" />

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="灰度图"

android:id="@+id/GetFaceButton"

android:layout_centerVertical="true"

android:layout_alignParentRight="true"

android:layout_alignParentEnd="true" />

<ImageView

android:adjustViewBounds="true"

android:maxHeight="400dp"

android:maxWidth="200dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:scaleType="fitStart"

android:id="@+id/IV02"

android:layout_below="@id/IV01" />

</RelativeLayout>

主程序java文件

package com.example.administrator.tryopencv2;

import android.content.ContentResolver;

import android.content.Intent;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.net.Uri;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.ImageView;

import java.io.FileNotFoundException;

import java.io.InputStream;

import org.opencv.android.OpenCVLoader;

import org.opencv.android.Utils;

import org.opencv.core.Mat;

import org.opencv.imgproc.Imgproc;

public class tryOpenCv2Activity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_try_open_cv2 );

Button GiveFaceButton = (Button)findViewById(R.id.GiveFaceButton);

GiveFaceButton.setOnClickListener(new Button.OnClickListener()

{

public void onClick(View v)

{

Intent myIntent = new Intent();

//开启picture画面Type设置为image*

myIntent.setType("image/*");

//使用Intent.ACTION_GET_CONTENT这个Action

myIntent.setAction(Intent.ACTION_GET_CONTENT);

/*取得相片后返回本画面*/

startActivityForResult(myIntent,1);

}

});

Button GetFaceButton = (Button)findViewById(R.id.GetFaceButton);

GetFaceButton.setOnClickListener(new Button.OnClickListener()

{

public void onClick(View v)

{

Intent myIntent = new Intent();

//开启picture画面Type设置为image*

myIntent.setType("image/*");

//使用Intent.ACTION_GET_CONTENT这个Action

myIntent.setAction(Intent.ACTION_GET_CONTENT);

/*取得相片后返回本画面*/

startActivityForResult(myIntent,2);

}

});

}

protected void onActivityResult(int requestCode,int resultCode,Intent data)

{

switch (requestCode)

{

case 1 :

Uri uri = data.getData();

Log.e("uri",uri.toString());

ContentResolver cr = this.getContentResolver();

try

{

InputStream input = cr.openInputStream(uri);

BitmapFactory.Options options = new BitmapFactory.Options();

options.inJustDecodeBounds = true;

BitmapFactory.decodeStream(input, null, options);

if (options.outWidth > 1024 || options.outHeight > 1024){

options.inSampleSize = Math.max(options.outWidth / 1024, options.outHeight/1024);

}

options.inJustDecodeBounds = false;

Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri), null, options);

/*以下进行灰度化处理（使用C++写底层函数jni调用）*/

/*

int w = bitmap.getWidth();

int h = bitmap.getHeight();

int[] pix = new int[w * h];

bitmap.getPixels(pix, 0, w, 0, 0, w, h);

int[] resultPixels = OpenCVHelper.gray(pix, w, h);

Bitmap result = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);

result.setPixels(resultPixels,0,w,0,0,w,h);

*/

ImageView imageView = (ImageView)findViewById(R.id.IV01);

/*将处理好的灰度图设定到ImageView*/

imageView.setImageBitmap(bitmap);

}

catch(FileNotFoundException e)

{

Log.e("Exception",e.getMessage(),e);

}

break;

case 2:

Uri uri2 = data.getData();

Log.e("uri2",uri2.toString());

ContentResolver cr2 = this.getContentResolver();

try

{

InputStream input = cr2.openInputStream(uri2);

BitmapFactory.Options options = new BitmapFactory.Options();

options.inJustDecodeBounds = true;

BitmapFactory.decodeStream(input, null, options);

if (options.outWidth > 1024 || options.outHeight > 1024){

options.inSampleSize = Math.max(options.outWidth / 1024, options.outHeight/1024);

}

options.inJustDecodeBounds = false;

Bitmap bitmap = BitmapFactory.decodeStream(cr2.openInputStream(uri2), null, options);

/*使用opencv包进行灰度化处理*/

OpenCVLoader.initDebug();

Mat rgbMat = new Mat();

Mat grayMat = new Mat();

Bitmap grayBitmap = Bitmap.createBitmap(bitmap.getWidth(),bitmap.getHeight(),Bitmap.Config.RGB_565);

Utils.bitmapToMat(bitmap,rgbMat);

Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);

Utils.matToBitmap(grayMat,grayBitmap);

/*将grayBitmap设定到ImageView*/

ImageView imageView = (ImageView)findViewById(R.id.IV02);

imageView.setImageBitmap(grayBitmap);

}

catch(FileNotFoundException e)

{

Log.e("Exception",e.getMessage(),e);

}

break;

default:

break;

}

super.onActivityResult(requestCode, resultCode, data);

}

}

运行即可，运行中会遇到，在opencv某个文件中出现找不到R包的错误，出现错误时，进入那个文件，导入自己的R包即可

运行结果：