Android 使用 OpenCV 在相机视图中进行实时 DFT
Android Real Time DFT in Camera View using OpenCV
我一直在努力实现一个 Android 直接在相机视图上应用 DFT 的应用程序。在 Whosebug 上进行研究，我可以找到以下主题：
SOLVED - Load Image in Mat and Display after DFT process
SOLVED - Load Image in Mat and Display after DFT process
Convert OpenCv DCT to Android
我也尝试过使用 JNI 的不同解决方案：
http://allaboutee.com/2011/11/12/discrete-fourier-transform-in-android-with-opencv/
然后我可以实现我的主要 Activity 代码：
package ch.hepia.lsn.opencv_native_androidstudio;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceView;
import android.view.WindowManager;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import android.hardware.Camera;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Rect;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2 {
private static final String TAG = "OCVSample::Activity";
private CameraBridgeViewBase mOpenCvCameraView;
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS: {
Log.i(TAG, "OpenCV loaded successfully");
mOpenCvCameraView.enableView();
}
break;
default: {
super.onManagerConnected(status);
}
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load ndk built module, as specified
// in moduleName in build.gradle
System.loadLibrary("native");
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.activity_main);
mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.main_surface);
mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraView.setCvCameraViewListener(this);
}
@Override
public void onPause() {
super.onPause();
disableCamera();
}
@Override
public void onResume() {
super.onResume();
if (!OpenCVLoader.initDebug()) {
Log.d(TAG, "Internal OpenCV library not found. Using OpenCV Manager for initialization");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);
} else {
Log.d(TAG, "OpenCV library found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
}
public void onDestroy() {
super.onDestroy();
disableCamera();
}
public void disableCamera() {
if (mOpenCvCameraView != null)
mOpenCvCameraView.disableView();
}
public void onCameraViewStarted(int width, int height) {
}
public void onCameraViewStopped() {
}
private Mat getDFT(Mat singleChannel) {
singleChannel.convertTo(singleChannel, CvType.CV_64FC1);
int m = Core.getOptimalDFTSize(singleChannel.rows());
int n = Core.getOptimalDFTSize(singleChannel.cols()); // on the border
// add zero
// values
// Imgproc.copyMakeBorder(image1,
// padded, 0, m -
// image1.rows(), 0, n
Mat padded = new Mat(new Size(n, m), CvType.CV_64FC1); // expand input
// image to
// optimal size
Core.copyMakeBorder(singleChannel, padded, 0, m - singleChannel.rows(), 0,
n - singleChannel.cols(), Core.BORDER_CONSTANT);
List<Mat> planes = new ArrayList<Mat>();
planes.add(padded);
planes.add(Mat.zeros(padded.rows(), padded.cols(), CvType.CV_64FC1));
Mat complexI = Mat.zeros(padded.rows(), padded.cols(), CvType.CV_64FC2);
Mat complexI2 = Mat
.zeros(padded.rows(), padded.cols(), CvType.CV_64FC2);
Core.merge(planes, complexI); // Add to the expanded another plane with
// zeros
Core.dft(complexI, complexI2); // this way the result may fit in the
// source matrix
// compute the magnitude and switch to logarithmic scale
// => log(1 + sqrt(Re(DFT(I))^2 + Im(DFT(I))^2))
Core.split(complexI2, planes); // planes[0] = Re(DFT(I), planes[1] =
// Im(DFT(I))
Mat mag = new Mat(planes.get(0).size(), planes.get(0).type());
Core.magnitude(planes.get(0), planes.get(1), mag);// planes[0]
// =
// magnitude
Mat magI = mag;
Mat magI2 = new Mat(magI.size(), magI.type());
Mat magI3 = new Mat(magI.size(), magI.type());
Mat magI4 = new Mat(magI.size(), magI.type());
Mat magI5 = new Mat(magI.size(), magI.type());
Core.add(magI, Mat.ones(padded.rows(), padded.cols(), CvType.CV_64FC1),
magI2); // switch to logarithmic scale
Core.log(magI2, magI3);
Mat crop = new Mat(magI3, new Rect(0, 0, magI3.cols() & -2,
magI3.rows() & -2));
magI4 = crop.clone();
// rearrange the quadrants of Fourier image so that the origin is at the
// image center
int cx = magI4.cols() / 2;
int cy = magI4.rows() / 2;
Rect q0Rect = new Rect(0, 0, cx, cy);
Rect q1Rect = new Rect(cx, 0, cx, cy);
Rect q2Rect = new Rect(0, cy, cx, cy);
Rect q3Rect = new Rect(cx, cy, cx, cy);
Mat q0 = new Mat(magI4, q0Rect); // Top-Left - Create a ROI per quadrant
Mat q1 = new Mat(magI4, q1Rect); // Top-Right
Mat q2 = new Mat(magI4, q2Rect); // Bottom-Left
Mat q3 = new Mat(magI4, q3Rect); // Bottom-Right
Mat tmp = new Mat(); // swap quadrants (Top-Left with Bottom-Right)
q0.copyTo(tmp);
q3.copyTo(q0);
tmp.copyTo(q3);
q1.copyTo(tmp); // swap quadrant (Top-Right with Bottom-Left)
q2.copyTo(q1);
tmp.copyTo(q2);
Core.normalize(magI4, magI5, 0, 255, Core.NORM_MINMAX);
Mat realResult = new Mat(magI5.size(), CvType.CV_8UC1);
magI5.convertTo(realResult, CvType.CV_8UC1);
return realResult;
}
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
//System.out.print("teste");
Mat matGray = inputFrame.gray();
return getDFT(inputFrame.gray());
}
}
但问题是，我仍然收到此错误：
07-03 22:46:46.205
13700-28322/ch.hepia.lsn.opencv_native_androidstudio A/libc: Fatal
signal 11 (SIGSEGV), code 1, fault addr 0x10 in tid 28322
(Thread-9802)
我认为这是因为某些处理限制，因为我只是复制了与其他用户一起使用普通图像的代码。
我的问题是：
如何检查此错误是否是由于处理限制引起的？
还有其他方法可以使用OpenCV或其他库实现吗？
谢谢。
我已将最初 post 编辑的代码移植到 Android Studio（来自 Eclipse）和 OpenCV 3.1.0。我认为此版本的 openCV 中的 Core.add() 函数存在问题 - 请参阅 post here
我按照建议使用了 Core.addWeighted() 并且我至少可以让 dft 显示但不久之后它就会 运行 内存不足。我 认为 类似 split 的函数也使用 add() 所以我认为我们需要在 openCV 中查看该问题的修复程序。
我 post 编辑的代码可以改进以更好地利用资源，例如，保持键数组的静态分配，不要继续调用 size() 但再次保持静态，减少分配的垫子数量等。您还可以减小捕获图像的大小，因为垫子在更现代的手机（我有三星 S6）上会变得很大，所以使用
mOpenCvCameraView.setMaxFrameSize(176, 152);
或任何更易于管理的大小。
如果你想减少帧处理的数量，那么保留一个静态计数器，你在每次捕获帧时增加它，并且只有在计数器可以被 5、10 或其他任何东西整除时才调用 getDFT() 以仅处理那些第5、10帧等
我一直在努力实现一个 Android 直接在相机视图上应用 DFT 的应用程序。在 Whosebug 上进行研究，我可以找到以下主题：
SOLVED - Load Image in Mat and Display after DFT process
SOLVED - Load Image in Mat and Display after DFT process
Convert OpenCv DCT to Android
我也尝试过使用 JNI 的不同解决方案： http://allaboutee.com/2011/11/12/discrete-fourier-transform-in-android-with-opencv/
然后我可以实现我的主要 Activity 代码：
package ch.hepia.lsn.opencv_native_androidstudio;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceView;
import android.view.WindowManager;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import android.hardware.Camera;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Rect;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2 {
private static final String TAG = "OCVSample::Activity";
private CameraBridgeViewBase mOpenCvCameraView;
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS: {
Log.i(TAG, "OpenCV loaded successfully");
mOpenCvCameraView.enableView();
}
break;
default: {
super.onManagerConnected(status);
}
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load ndk built module, as specified
// in moduleName in build.gradle
System.loadLibrary("native");
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.activity_main);
mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.main_surface);
mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraView.setCvCameraViewListener(this);
}
@Override
public void onPause() {
super.onPause();
disableCamera();
}
@Override
public void onResume() {
super.onResume();
if (!OpenCVLoader.initDebug()) {
Log.d(TAG, "Internal OpenCV library not found. Using OpenCV Manager for initialization");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);
} else {
Log.d(TAG, "OpenCV library found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
}
public void onDestroy() {
super.onDestroy();
disableCamera();
}
public void disableCamera() {
if (mOpenCvCameraView != null)
mOpenCvCameraView.disableView();
}
public void onCameraViewStarted(int width, int height) {
}
public void onCameraViewStopped() {
}
private Mat getDFT(Mat singleChannel) {
singleChannel.convertTo(singleChannel, CvType.CV_64FC1);
int m = Core.getOptimalDFTSize(singleChannel.rows());
int n = Core.getOptimalDFTSize(singleChannel.cols()); // on the border
// add zero
// values
// Imgproc.copyMakeBorder(image1,
// padded, 0, m -
// image1.rows(), 0, n
Mat padded = new Mat(new Size(n, m), CvType.CV_64FC1); // expand input
// image to
// optimal size
Core.copyMakeBorder(singleChannel, padded, 0, m - singleChannel.rows(), 0,
n - singleChannel.cols(), Core.BORDER_CONSTANT);
List<Mat> planes = new ArrayList<Mat>();
planes.add(padded);
planes.add(Mat.zeros(padded.rows(), padded.cols(), CvType.CV_64FC1));
Mat complexI = Mat.zeros(padded.rows(), padded.cols(), CvType.CV_64FC2);
Mat complexI2 = Mat
.zeros(padded.rows(), padded.cols(), CvType.CV_64FC2);
Core.merge(planes, complexI); // Add to the expanded another plane with
// zeros
Core.dft(complexI, complexI2); // this way the result may fit in the
// source matrix
// compute the magnitude and switch to logarithmic scale
// => log(1 + sqrt(Re(DFT(I))^2 + Im(DFT(I))^2))
Core.split(complexI2, planes); // planes[0] = Re(DFT(I), planes[1] =
// Im(DFT(I))
Mat mag = new Mat(planes.get(0).size(), planes.get(0).type());
Core.magnitude(planes.get(0), planes.get(1), mag);// planes[0]
// =
// magnitude
Mat magI = mag;
Mat magI2 = new Mat(magI.size(), magI.type());
Mat magI3 = new Mat(magI.size(), magI.type());
Mat magI4 = new Mat(magI.size(), magI.type());
Mat magI5 = new Mat(magI.size(), magI.type());
Core.add(magI, Mat.ones(padded.rows(), padded.cols(), CvType.CV_64FC1),
magI2); // switch to logarithmic scale
Core.log(magI2, magI3);
Mat crop = new Mat(magI3, new Rect(0, 0, magI3.cols() & -2,
magI3.rows() & -2));
magI4 = crop.clone();
// rearrange the quadrants of Fourier image so that the origin is at the
// image center
int cx = magI4.cols() / 2;
int cy = magI4.rows() / 2;
Rect q0Rect = new Rect(0, 0, cx, cy);
Rect q1Rect = new Rect(cx, 0, cx, cy);
Rect q2Rect = new Rect(0, cy, cx, cy);
Rect q3Rect = new Rect(cx, cy, cx, cy);
Mat q0 = new Mat(magI4, q0Rect); // Top-Left - Create a ROI per quadrant
Mat q1 = new Mat(magI4, q1Rect); // Top-Right
Mat q2 = new Mat(magI4, q2Rect); // Bottom-Left
Mat q3 = new Mat(magI4, q3Rect); // Bottom-Right
Mat tmp = new Mat(); // swap quadrants (Top-Left with Bottom-Right)
q0.copyTo(tmp);
q3.copyTo(q0);
tmp.copyTo(q3);
q1.copyTo(tmp); // swap quadrant (Top-Right with Bottom-Left)
q2.copyTo(q1);
tmp.copyTo(q2);
Core.normalize(magI4, magI5, 0, 255, Core.NORM_MINMAX);
Mat realResult = new Mat(magI5.size(), CvType.CV_8UC1);
magI5.convertTo(realResult, CvType.CV_8UC1);
return realResult;
}
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
//System.out.print("teste");
Mat matGray = inputFrame.gray();
return getDFT(inputFrame.gray());
}
}
但问题是，我仍然收到此错误：
07-03 22:46:46.205 13700-28322/ch.hepia.lsn.opencv_native_androidstudio A/libc: Fatal signal 11 (SIGSEGV), code 1, fault addr 0x10 in tid 28322 (Thread-9802)
我认为这是因为某些处理限制，因为我只是复制了与其他用户一起使用普通图像的代码。
我的问题是：
如何检查此错误是否是由于处理限制引起的？
还有其他方法可以使用OpenCV或其他库实现吗？
谢谢。
我已将最初 post 编辑的代码移植到 Android Studio（来自 Eclipse）和 OpenCV 3.1.0。我认为此版本的 openCV 中的 Core.add() 函数存在问题 - 请参阅 post here
我按照建议使用了 Core.addWeighted() 并且我至少可以让 dft 显示但不久之后它就会 运行 内存不足。我 认为 类似 split 的函数也使用 add() 所以我认为我们需要在 openCV 中查看该问题的修复程序。
我 post 编辑的代码可以改进以更好地利用资源，例如，保持键数组的静态分配，不要继续调用 size() 但再次保持静态，减少分配的垫子数量等。您还可以减小捕获图像的大小，因为垫子在更现代的手机（我有三星 S6）上会变得很大，所以使用
mOpenCvCameraView.setMaxFrameSize(176, 152);
或任何更易于管理的大小。
如果你想减少帧处理的数量，那么保留一个静态计数器，你在每次捕获帧时增加它，并且只有在计数器可以被 5、10 或其他任何东西整除时才调用 getDFT() 以仅处理那些第5、10帧等