我是Opencv的新手。我使用JavaCameraView， 它使用1280x 720相机分辨率。 如何将分辨率提高到500万像素？ 请帮帮我:)
答案 0 :(得分：2)
您需要选择相机允许的分辨率。在onCameraViewStarted函数中调用以下代码并设置listNum，使其对应于您想要的分辨率：
Parameters params = mCamera.getParameters();
List<Size> resList = mCamera.getParameters().getSupportedPictureSizes();
int listNum = 1;// 0 is the maximum resolution
int width = resList.get(listNum).width;
int height = resList.get(listNum).height;
params.setPictureSize(width, height);
mCamera.setParameters(params);
mCamera是你的org.opencv.android.JavaCameraView对象。
布赖恩
答案 1 :(得分：1)
似乎OpenCV Camera（JavaCameraView）已设置为默认最大分辨率1280 * 720。
我们可以使用以下方法降低分辨率：
cameraView.setMaxFrameSize(320, 280);
或
cameraView.setMaxFrameSize(480, 320);
或者
cameraView.setMaxFrameSize(640, 480);
或者
cameraView.setMaxFrameSize(800, 600);
或者
cameraView.setMaxFrameSize(1280, 720);
现在，问题是如果我的手机支持更高分辨率，如何提高分辨率。为此，我们必须制作我们自己的定制JavaCameraView（让我们说MyCameraView）。
只需将JavaCameraView复制并粘贴到MyCameraView，然后根据需要进行更正。
我在我的案例中做了以下更正：
package com.example.opencvcamera;
import org.opencv.android.CameraBridgeViewBase;
import android.hardware.Camera;
import java.util.List;
import android.content.Context;
import android.graphics.ImageFormat;
import android.graphics.SurfaceTexture;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.ViewGroup.LayoutParams;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
/**
* Created by Kumar.Vaibhav on 19-04-2017.
*/
public class MyCameraView extends CameraBridgeViewBase implements Camera.PreviewCallback {
private static final int MAGIC_TEXTURE_ID = 10;
private static final String TAG = "MyCameraView";
private byte mBuffer[];
private Mat[] mFrameChain;
private int mChainIdx = 0;
private Thread mThread;
private boolean mStopThread;
protected Camera mCamera;
protected MyCameraView.JavaCameraFrame[] mCameraFrame;
private SurfaceTexture mSurfaceTexture;
public static class JavaCameraSizeAccessor implements ListItemAccessor {
@Override
public int getWidth(Object obj) {
Camera.Size size = (Camera.Size) obj;
return size.width;
}
@Override
public int getHeight(Object obj) {
Camera.Size size = (Camera.Size) obj;
return size.height;
}
}
public MyCameraView(Context context, int cameraId) {
super(context, cameraId);
}
public MyCameraView(Context context, AttributeSet attrs) {
super(context, attrs);
}
protected boolean initializeCamera(int width, int height) {
Log.d(TAG, "Initialize java camera");
boolean result = true;
synchronized (this) {
mCamera = null;
if (mCameraIndex == CAMERA_ID_ANY) {
Log.d(TAG, "Trying to open camera with old open()");
try {
mCamera = Camera.open();
}
catch (Exception e){
Log.e(TAG, "Camera is not available (in use or does not exist): " + e.getLocalizedMessage());
}
if(mCamera == null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
boolean connected = false;
for (int camIdx = 0; camIdx < Camera.getNumberOfCameras(); ++camIdx) {
Log.d(TAG, "Trying to open camera with new open(" + Integer.valueOf(camIdx) + ")");
try {
mCamera = Camera.open(camIdx);
connected = true;
} catch (RuntimeException e) {
Log.e(TAG, "Camera #" + camIdx + "failed to open: " + e.getLocalizedMessage());
}
if (connected) break;
}
}
} else {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
int localCameraIndex = mCameraIndex;
if (mCameraIndex == CAMERA_ID_BACK) {
Log.i(TAG, "Trying to open back camera");
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
for (int camIdx = 0; camIdx < Camera.getNumberOfCameras(); ++camIdx) {
Camera.getCameraInfo( camIdx, cameraInfo );
if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
localCameraIndex = camIdx;
break;
}
}
} else if (mCameraIndex == CAMERA_ID_FRONT) {
Log.i(TAG, "Trying to open front camera");
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
for (int camIdx = 0; camIdx < Camera.getNumberOfCameras(); ++camIdx) {
Camera.getCameraInfo( camIdx, cameraInfo );
if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
localCameraIndex = camIdx;
break;
}
}
}
if (localCameraIndex == CAMERA_ID_BACK) {
Log.e(TAG, "Back camera not found!");
} else if (localCameraIndex == CAMERA_ID_FRONT) {
Log.e(TAG, "Front camera not found!");
} else {
Log.d(TAG, "Trying to open camera with new open(" + Integer.valueOf(localCameraIndex) + ")");
try {
mCamera = Camera.open(localCameraIndex);
} catch (RuntimeException e) {
Log.e(TAG, "Camera #" + localCameraIndex + "failed to open: " + e.getLocalizedMessage());
}
}
}
}
if (mCamera == null)
return false;
/* Now set camera parameters */
try {
Camera.Parameters params = mCamera.getParameters();
Log.d(TAG, "getSupportedPreviewSizes()");
List<android.hardware.Camera.Size> sizes = params.getSupportedPreviewSizes();
if (sizes != null) {
/* Select the size that fits surface considering maximum size allowed */
//Size frameSize = calculateCameraFrameSize(sizes, new MyCameraView.JavaCameraSizeAccessor(), width, height);
Camera.Size mSizePicture =sizes.get(0);
if(mSizePicture.width<3264 && mSizePicture.height<2448)
{
int cameraSize= sizes.size();
mSizePicture =sizes.get(cameraSize-1);
}
/*params.setPreviewFormat(ImageFormat.NV21);
Log.d(TAG, "Set preview size to " + Integer.valueOf((int)frameSize.width) + "x" + Integer.valueOf((int)frameSize.height));
params.setPreviewSize((int)frameSize.width, (int)frameSize.height);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH && !android.os.Build.MODEL.equals("GT-I9100"))
params.setRecordingHint(true);*/
List<String> FocusModes = params.getSupportedFocusModes();
if (FocusModes != null && FocusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO))
{
params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
}
mCamera.setParameters(params);
params = mCamera.getParameters();
mFrameWidth = params.getPreviewSize().width;
mFrameHeight = params.getPreviewSize().height;
if ((getLayoutParams().width == LayoutParams.MATCH_PARENT) && (getLayoutParams().height == LayoutParams.MATCH_PARENT))
mScale = Math.min(((float)height)/mFrameHeight, ((float)width)/mFrameWidth);
else
mScale = 0;
if (mFpsMeter != null) {
mFpsMeter.setResolution(mFrameWidth, mFrameHeight);
}
int size = mFrameWidth * mFrameHeight;
size = size * ImageFormat.getBitsPerPixel(params.getPreviewFormat()) / 8;
mBuffer = new byte[size];
mCamera.addCallbackBuffer(mBuffer);
mCamera.setPreviewCallbackWithBuffer(this);
mFrameChain = new Mat[2];
mFrameChain[0] = new Mat(mFrameHeight + (mFrameHeight/2), mFrameWidth, CvType.CV_8UC1);
mFrameChain[1] = new Mat(mFrameHeight + (mFrameHeight/2), mFrameWidth, CvType.CV_8UC1);
AllocateCache();
mCameraFrame = new MyCameraView.JavaCameraFrame[2];
mCameraFrame[0] = new MyCameraView.JavaCameraFrame(mFrameChain[0], mFrameWidth, mFrameHeight);
mCameraFrame[1] = new MyCameraView.JavaCameraFrame(mFrameChain[1], mFrameWidth, mFrameHeight);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
mSurfaceTexture = new SurfaceTexture(MAGIC_TEXTURE_ID);
mCamera.setPreviewTexture(mSurfaceTexture);
} else
mCamera.setPreviewDisplay(null);
/* Finally we are ready to start the preview */
Log.d(TAG, "startPreview");
mCamera.startPreview();
}
else
result = false;
} catch (Exception e) {
result = false;
e.printStackTrace();
}
}
return result;
}
protected void releaseCamera() {
synchronized (this) {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.setPreviewCallback(null);
mCamera.release();
}
mCamera = null;
if (mFrameChain != null) {
mFrameChain[0].release();
mFrameChain[1].release();
}
if (mCameraFrame != null) {
mCameraFrame[0].release();
mCameraFrame[1].release();
}
}
}
private boolean mCameraFrameReady = false;
@Override
protected boolean connectCamera(int width, int height) {
/* 1. We need to instantiate camera
* 2. We need to start thread which will be getting frames
*/
/* First step - initialize camera connection */
Log.d(TAG, "Connecting to camera");
if (!initializeCamera(width, height))
return false;
mCameraFrameReady = false;
/* now we can start update thread */
Log.d(TAG, "Starting processing thread");
mStopThread = false;
mThread = new Thread(new CameraWorker());
mThread.start();
return true;
}
@Override
protected void disconnectCamera() {
/* 1. We need to stop thread which updating the frames
* 2. Stop camera and release it
*/
Log.d(TAG, "Disconnecting from camera");
try {
mStopThread = true;
Log.d(TAG, "Notify thread");
synchronized (this) {
this.notify();
}
Log.d(TAG, "Wating for thread");
if (mThread != null)
mThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
mThread = null;
}
/* Now release camera */
releaseCamera();
mCameraFrameReady = false;
}
@Override
public void onPreviewFrame(byte[] frame, Camera arg1) {
Log.d(TAG, "Preview Frame received. Frame size: " + frame.length);
synchronized (this) {
mFrameChain[mChainIdx].put(0, 0, frame);
mCameraFrameReady = true;
this.notify();
}
if (mCamera != null)
mCamera.addCallbackBuffer(mBuffer);
}
private class JavaCameraFrame implements CvCameraViewFrame {
@Override
public Mat gray() {
return mYuvFrameData.submat(0, mHeight, 0, mWidth);
}
@Override
public Mat rgba() {
Imgproc.cvtColor(mYuvFrameData, mRgba, Imgproc.COLOR_YUV2RGBA_NV21, 4);
return mRgba;
}
public JavaCameraFrame(Mat Yuv420sp, int width, int height) {
super();
mWidth = width;
mHeight = height;
mYuvFrameData = Yuv420sp;
mRgba = new Mat();
}
public void release() {
mRgba.release();
}
private Mat mYuvFrameData;
private Mat mRgba;
private int mWidth;
private int mHeight;
};
private class CameraWorker implements Runnable {
@Override
public void run() {
do {
boolean hasFrame = false;
synchronized (MyCameraView.this) {
try {
while (!mCameraFrameReady && !mStopThread) {
MyCameraView.this.wait();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
if (mCameraFrameReady)
{
mChainIdx = 1 - mChainIdx;
mCameraFrameReady = false;
hasFrame = true;
}
}
if (!mStopThread && hasFrame) {
if (!mFrameChain[1 - mChainIdx].empty())
deliverAndDrawFrame(mCameraFrame[1 - mChainIdx]);
}
} while (!mStopThread);
Log.d(TAG, "Finish processing thread");
}
}
}
同样将activity_main.xml更改为：
<com.example.opencvcamera.MyCameraView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/java_camera_view"
android:visibility="visible"/>