如何在Android上更改相机曝光? [英] How to change camera exposure on android?
问题描述
我想使用OpenCV和android执行图像处理.第一步,我需要更改相机属性,例如分辨率,曝光度等.通过使用OpenCV,我只能更改分辨率( mOpenCvCameraView.setMaxFrameSize(320,240);
),并且不能更改曝光度.
I want to perform image processing with OpenCV and android. In the first step, I need to change the camera properties like resolution, exposure, etc. By using OpenCV I only can change the resolution(mOpenCvCameraView.setMaxFrameSize(320,240);
) and cannot change exposure.
使用OpenCV和camera2时,它崩溃了(此代码: pastebin.com/3XgvKGQN
).
如何更改相机的曝光?
By using OpenCV and camera2 When I run it, it is crashing(this code:pastebin.com/3XgvKGQN
).
How can I change camera exposure?
package com.williams.drew.opencvtest;
import android.graphics.Paint;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureRequest;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.SurfaceView;
import android.view.WindowManager;
import org.opencv.android.JavaCameraView;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
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.imgproc.Imgproc;
public class MainActivity extends AppCompatActivity implements CvCameraViewListener2 {
//Prefixes for logging success and failure messages
private static final String TAG = "OCVSample::Activity";
//Loads camera view of OpenCV for us to use. This lets us see using OpenCV
private CameraBridgeViewBase mOpenCvCameraView;
//Preview Builder which changes exposure (i think)
private CaptureRequest.Builder mPreviewRequestBuilder;
private CaptureRequest mPreviewRequest;
private long exposureTime = 1000,frameDuration = 1000;
private int sensitivity = 200;
//OPENCV Variables
Mat matRGBA;
public MainActivity() {
Log.i(TAG, "Instantiated new " + this.getClass());
}
@Override
protected void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "called onCreate");
super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.show_camera);
mOpenCvCameraView = (JavaCameraView) findViewById(R.id.show_camera_activity_java_surface_view);
mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraView.setCvCameraViewListener(this);
}
@Override
public void onPause() {
super.onPause();
if(mOpenCvCameraView != null) {
mOpenCvCameraView.disableView();
}
}
@Override
public void onResume() {
super.onResume();
if(!OpenCVLoader.initDebug()) {
Log.d(TAG, "Internal OpenCV library not found. Using OpenCV Manager for init");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_1_0, this, mLoaderCallback);
}
else {
Log.d(TAG, "OpenCV library found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
}
@Override
public void onDestroy() {
super.onDestroy();
if(mOpenCvCameraView != null) {
mOpenCvCameraView.disableView();
}
}
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);
} break;
}
}
};
@Override
public void onCameraViewStarted(int width, int height) {
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_OFF);
mPreviewRequestBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME, Long.valueOf(exposureTime));
mPreviewRequestBuilder.set(CaptureRequest.SENSOR_SENSITIVITY, Integer.valueOf(sensitivity));
mPreviewRequestBuilder.set(CaptureRequest.SENSOR_FRAME_DURATION, Long.valueOf(frameDuration));
matRGBA = new Mat(width, height, CvType.CV_8UC4);
}
@Override
public void onCameraViewStopped() {
matRGBA.release();
}
@Override
public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
matRGBA = inputFrame.rgba();
return matRGBA;
}
}
谢谢您的回答.
推荐答案
是的,OpenCV不会公开所有相机参数.您可以修改 JavaCameraView
并添加调用 setExposureCompensation()
的函数.
Yes, OpenCV is not exposing all the camera parameters. You can modify JavaCameraView
and add the function that calls setExposureCompensation()
.
您要这样调用该函数:
Camera mCamera;
mCamera = Camera.open();
Camera.Parameters params = mCamera.getParameters();
params.setExposureCompensation(0);
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