安卓：在服务中使用的OpenCV VideoCapture [英] Android: using OpenCV VideoCapture in service
本文介绍了安卓：在服务中使用的OpenCV VideoCapture的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我使用的是启动Android设备启动时的服务。这是因为我并不需要一个可见的活动。正常工作为止。但是现在我试图打开相机（在MyService.onStart），并做一些基本的图像处理。我理解的是默认的Android相机类需要进行视频preVIEW的表面。这就是为什么我想要使用的OpenCV的VideoCapture。
但我得到这个错误：
没有找到实现本机
Lorg / OpenCV的/ highgui / VideoCapture; .n_VideoCapture：（I）Ĵ我不知道这是否是因为我没有以下行中使用的主要活动OpenCV的例子中使用。问题是，如何这在我服务的整合，当初始化VideoCapture成员。
OpenCVLoader.initAsync（OpenCVLoader.OPENCV_VERSION_2_4_5，对此，mLoaderCallback）;下面是我的code为止。大多数OpenCV的code是从OpenCV中的NativeCameraView和CameraBridgeViewBase采取
包com.example.boot;进口org.opencv.android.Utils;
进口org.opencv.core.Mat;
进口org.opencv.core.Size;
进口org.opencv.highgui.Highgui;
进口org.opencv.highgui.VideoCapture;进口android.app.Service;
进口android.content.Intent;
进口android.graphics.Bitmap;
进口android.os.IBinder;
进口android.util.Log;
进口android.widget.Toast;公共最后一类为MyService延伸服务
{
私有静态最后弦乐TAG =为MyService
私人布尔mStopThread;
私人螺纹mThread;
私人VideoCapture mCamera;
私人诠释mFrameWidth;
私人诠释mFrameHeight;
私人INT mCameraIndex = -1;
私人位图mCacheBitmap; @覆盖
公众的IBinder onBind（意向意图）{
返回null;
} 公共无效的onDestroy（）{ this.disconnectCamera（）; Toast.makeText（这一点，停止服务，Toast.LENGTH_LONG）.show（）;
Log.d（TAG的onDestroy）;
} @覆盖
公共无效调用onStart（意向意图，诠释startid）
{
Log.d（TAG，service.onStart：开始）; 尝试
{
如果（！connectCamera（640，480））
Log.e（TAG，无法连接相机）;
其他
Log.d（TAG相机连接成功）;
}
赶上（例外五）
{
Log.e（TAGMyServer.connectCamera抛出一个异常：+ e.getMessage（））;
} Toast.makeText（这一点，服务启动，Toast.LENGTH_LONG）.show（）;
Log.d（TAG，service.onStart：末）;
} 私人布尔connectCamera（INT宽度，高度INT）{
/ *第一步 - 初始化相机连接* /
如果（！initializeCamera（宽度，高度））
返回false; / *现在我们可以开始更新线程* /
mThread =新主题（新CameraWorker（））;
mThread.start（）; 返回true;
} 私人布尔initializeCamera（INT宽度，高度INT）{
同步（本）{ 如果（mCameraIndex == -1）
mCamera =新VideoCapture（Highgui.CV_CAP_ANDROID）;
其他
mCamera =新VideoCapture（Highgui.CV_CAP_ANDROID + mCameraIndex）; 如果（mCamera == NULL）
返回false; 如果（mCamera.isOpened（）== FALSE）
返回false; //java.util.List<Size>大小= mCamera.getSupported previewSizes（）; / *选择适合面考虑允许的最大值大小* /
尺寸框架尺寸=新尺寸（宽，高）; mFrameWidth =（INT）frameSize.width;
mFrameHeight =（INT）frameSize.height; AllocateCache（）; mCamera.set（Highgui.CV_CAP_PROP_FRAME_WIDTH，frameSize.width）;
mCamera.set（Highgui.CV_CAP_PROP_FRAME_HEIGHT，frameSize.height）;
} Log.i（TAG，选择的摄像机帧大小=（+ mFrameWidth +，+ mFrameHeight +））; 返回true;
} 保护无效AllocateCache（）
{
mCacheBitmap = Bitmap.createBitmap（mFrameWidth，mFrameHeight，Bitmap.Config.ARGB_8888）;
} 私人无效releaseCamera（）{
同步（本）{
如果（mCamera！= NULL）{
mCamera.release（）;
}
}
} 私人无效disconnectCamera（）{
/ * 1，我们需要停止线程哪个更新帧
* 2.停止相机和释放
* /
尝试{
mStopThread = TRUE;
mThread.join（）;
}赶上（InterruptedException的E）{
e.printStackTrace（）;
} {最后
mThread = NULL;
mStopThread = FALSE;
} / *现在松开相机* /
releaseCamera（）;
} 保护无效deliverAndDrawFrame（NativeCameraFrame帧）
{
垫修改= frame.rgba（）; 布尔bmpValid =真;
如果（修改！= NULL）{
尝试{
Utils.matToBitmap（修改，mCacheBitmap）;
}赶上（例外五）{
Log.e（TAG，垫类型：+修改）;
Log.e（TAG，位图类型：+ mCacheBitmap.getWidth（）+*+ mCacheBitmap.getHeight（））;
Log.e（TAGUtils.matToBitmap（）抛出一个异常：+ e.getMessage（））;
bmpValid = FALSE;
}
}
} 私有类NativeCameraFrame
{
公共垫RGBA（）{
mCapture.retrieve（mRgba，Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA）;
返回mRgba;
} 公共垫灰色（）{
mCapture.retrieve（mGray，Highgui.CV_CAP_ANDROID_GREY_FRAME）;
返回mGray;
} 公共NativeCameraFrame（VideoCapture捕获）{
mCapture =捕捉;
mGray =新垫（）;
mRgba =新垫（）;
} 私人VideoCapture mCapture;
私人垫mRgba;
私人垫mGray;
}; 私有类CameraWorker实现Runnable
{
公共无效的run（）
{
做
{
如果（！mCamera.grab（））{
Log.e（TAG相机架抢失败）;
打破;
} deliverAndDrawFrame（新NativeCameraFrame（mCamera））; }而（！mStopThread）;
}
}
}
解决方案你提到的线（
initAsync）实际上是用来加载OpenCV的经理。这应该是你做的第一件事，因此它也许应该去年初在onStart（）。I'm using a service that is started when the Android device boots. This is because I don't need a visible activity. Works fine so far. But now I'm trying to open the camera (in MyService.onStart) and do some basic image processing. I understood that the default Android camera class needs a surface for video preview. That's why I want to use the VideoCapture from OpenCV.
But I get this error:
No implementation found for native Lorg/opencv/highgui/VideoCapture;.n_VideoCapture:(I)J
I'm wondering if this is because I don't have the following line as used in OpenCV examples using a main Activity. The question is, how to integrate this in my service and when to initialize the VideoCapture member.
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_5, this, mLoaderCallback);Here's my code so far. Most of the OpenCV code is taken from OpenCV's NativeCameraView and CameraBridgeViewBase
package com.example.boot; import org.opencv.android.Utils; import org.opencv.core.Mat; import org.opencv.core.Size; import org.opencv.highgui.Highgui; import org.opencv.highgui.VideoCapture; import android.app.Service; import android.content.Intent; import android.graphics.Bitmap; import android.os.IBinder; import android.util.Log; import android.widget.Toast; public final class MyService extends Service { private static final String TAG = "MyService"; private boolean mStopThread; private Thread mThread; private VideoCapture mCamera; private int mFrameWidth; private int mFrameHeight; private int mCameraIndex = -1; private Bitmap mCacheBitmap; @Override public IBinder onBind(Intent intent) { return null; } public void onDestroy() { this.disconnectCamera(); Toast.makeText(this, "service stopped", Toast.LENGTH_LONG).show(); Log.d(TAG, "onDestroy"); } @Override public void onStart(Intent intent, int startid) { Log.d(TAG, "service.onStart: begin"); try { if (!connectCamera(640, 480)) Log.e(TAG, "Could not connect camera"); else Log.d(TAG, "Camera successfully connected"); } catch(Exception e) { Log.e(TAG, "MyServer.connectCamera throws an exception: " + e.getMessage()); } Toast.makeText(this, "service started", Toast.LENGTH_LONG).show(); Log.d(TAG, "service.onStart: end"); } private boolean connectCamera(int width, int height) { /* First step - initialize camera connection */ if (!initializeCamera(width, height)) return false; /* now we can start update thread */ mThread = new Thread(new CameraWorker()); mThread.start(); return true; } private boolean initializeCamera(int width, int height) { synchronized (this) { if (mCameraIndex == -1) mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID); else mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID + mCameraIndex); if (mCamera == null) return false; if (mCamera.isOpened() == false) return false; //java.util.List<Size> sizes = mCamera.getSupportedPreviewSizes(); /* Select the size that fits surface considering maximum size allowed */ Size frameSize = new Size(width, height); mFrameWidth = (int)frameSize.width; mFrameHeight = (int)frameSize.height; AllocateCache(); mCamera.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, frameSize.width); mCamera.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, frameSize.height); } Log.i(TAG, "Selected camera frame size = (" + mFrameWidth + ", " + mFrameHeight + ")"); return true; } protected void AllocateCache() { mCacheBitmap = Bitmap.createBitmap(mFrameWidth, mFrameHeight, Bitmap.Config.ARGB_8888); } private void releaseCamera() { synchronized (this) { if (mCamera != null) { mCamera.release(); } } } private void disconnectCamera() { /* 1. We need to stop thread which updating the frames * 2. Stop camera and release it */ try { mStopThread = true; mThread.join(); } catch (InterruptedException e) { e.printStackTrace(); } finally { mThread = null; mStopThread = false; } /* Now release camera */ releaseCamera(); } protected void deliverAndDrawFrame(NativeCameraFrame frame) { Mat modified = frame.rgba(); boolean bmpValid = true; if (modified != null) { try { Utils.matToBitmap(modified, mCacheBitmap); } catch(Exception e) { Log.e(TAG, "Mat type: " + modified); Log.e(TAG, "Bitmap type: " + mCacheBitmap.getWidth() + "*" + mCacheBitmap.getHeight()); Log.e(TAG, "Utils.matToBitmap() throws an exception: " + e.getMessage()); bmpValid = false; } } } private class NativeCameraFrame { public Mat rgba() { mCapture.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA); return mRgba; } public Mat gray() { mCapture.retrieve(mGray, Highgui.CV_CAP_ANDROID_GREY_FRAME); return mGray; } public NativeCameraFrame(VideoCapture capture) { mCapture = capture; mGray = new Mat(); mRgba = new Mat(); } private VideoCapture mCapture; private Mat mRgba; private Mat mGray; }; private class CameraWorker implements Runnable { public void run() { do { if (!mCamera.grab()) { Log.e(TAG, "Camera frame grab failed"); break; } deliverAndDrawFrame(new NativeCameraFrame(mCamera)); } while (!mStopThread); } } }
解决方案The line you mention (
initAsync) is actually used to load the OpenCV Manager. That should be the very first thing you do, and therefore it should probably go in the beginning ofonStart().这篇关于安卓：在服务中使用的OpenCV VideoCapture的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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