OpenCV4Android的JavaCameraView组件以及调用前摄像头
1、布局文件activity_main.xml
2、MainActivity.java
package cn.daizhe.opencv4androiddemo;
import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
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.MatOfFloat;
import org.opencv.core.MatOfInt;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import java.util.Arrays;
import cn.daizhe.opencv4androiddemo.activity.PermissionsActivity;
import cn.daizhe.util.PermissionsChecker;
public class MainActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2 {
private String TAG = "OpenCV_Test";
//OpenCV的相机接口
private CameraBridgeViewBase mCVCamera;
//缓存相机每帧输入的数据
private Mat mRgba, mTmp;
//按钮组件
private Button mButton;
//当前处理状态
private static int Cur_State = 0;
private Size mSize0;
private Mat mIntermediateMat;
private MatOfInt mChannels[];
private MatOfInt mHistSize;
private int mHistSizeNum = 25;
private Mat mMat0;
private float[] mBuff;
private MatOfFloat mRanges;
private Point mP1;
private Point mP2;
private Scalar mColorsRGB[];
private Scalar mColorsHue[];
private Scalar mWhilte;
private Mat mSepiaKernel;
/**
* 通过OpenCV管理Android服务，异步初始化OpenCV
*/
BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS:
Log.i(TAG, "OpenCV loaded successfully");
mCVCamera.enableView();
break;
default:
break;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mCVCamera = (CameraBridgeViewBase) findViewById(R.id.camera_view);
mCVCamera.setCvCameraViewListener(this);
// 打开前置摄像头
//mCVCamera.setCameraIndex(CameraBridgeViewBase.CAMERA_ID_FRONT);
mButton = (Button) findViewById(R.id.deal_btn);
mButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (Cur_State < 8) {
//切换状态
Cur_State++;
} else {
//恢复初始状态
Cur_State = 0;
}
}
});
}
@Override
public void onResume() {
super.onResume();
if (!OpenCVLoader.initDebug()) {
Log.d(TAG, "OpenCV library not found!");
} else {
Log.d(TAG, "OpenCV library found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
}
@Override
public void onDestroy() {
if(mCVCamera!=null){
mCVCamera.disableView();
}
};
@Override
public void onCameraViewStarted(int width, int height) {
// TODO Auto-generated method stub
mRgba = new Mat(height, width, CvType.CV_8UC4);
mTmp = new Mat(height, width, CvType.CV_8UC4);
mIntermediateMat = new Mat();
mSize0 = new Size();
mChannels = new MatOfInt[]{new MatOfInt(0), new MatOfInt(1), new MatOfInt(2)};
mBuff = new float[mHistSizeNum];
mHistSize = new MatOfInt(mHistSizeNum);
mRanges = new MatOfFloat(0f, 256f);
mMat0 = new Mat();
mColorsRGB = new Scalar[]{new Scalar(200, 0, 0, 255), new Scalar(0, 200, 0, 255), new Scalar(0, 0, 200, 255)};
mColorsHue = new Scalar[]{
new Scalar(255, 0, 0, 255), new Scalar(255, 60, 0, 255), new Scalar(255, 120, 0, 255), new Scalar(255, 180, 0, 255), new Scalar(255, 240, 0, 255),
new Scalar(215, 213, 0, 255), new Scalar(150, 255, 0, 255), new Scalar(85, 255, 0, 255), new Scalar(20, 255, 0, 255), new Scalar(0, 255, 30, 255),
new Scalar(0, 255, 85, 255), new Scalar(0, 255, 150, 255), new Scalar(0, 255, 215, 255), new Scalar(0, 234, 255, 255), new Scalar(0, 170, 255, 255),
new Scalar(0, 120, 255, 255), new Scalar(0, 60, 255, 255), new Scalar(0, 0, 255, 255), new Scalar(64, 0, 255, 255), new Scalar(120, 0, 255, 255),
new Scalar(180, 0, 255, 255), new Scalar(255, 0, 255, 255), new Scalar(255, 0, 215, 255), new Scalar(255, 0, 85, 255), new Scalar(255, 0, 0, 255)
};
mWhilte = Scalar.all(255);
mP1 = new Point();
mP2 = new Point();
// Fill sepia kernel
mSepiaKernel = new Mat(4, 4, CvType.CV_32F);
mSepiaKernel.put(0, 0, /* R */0.189f, 0.769f, 0.393f, 0f);
mSepiaKernel.put(1, 0, /* G */0.168f, 0.686f, 0.349f, 0f);
mSepiaKernel.put(2, 0, /* B */0.131f, 0.534f, 0.272f, 0f);
mSepiaKernel.put(3, 0, /* A */0.000f, 0.000f, 0.000f, 1f);
}
@Override
public void onCameraViewStopped() {
// TODO Auto-generated method stub
mRgba.release();
mTmp.release();
}
/**
* 图像处理都写在此处
*/
@Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
mRgba = inputFrame.rgba();
Size sizeRgba = mRgba.size();
int rows = (int) sizeRgba.height;
int cols = (int) sizeRgba.width;
Mat rgbaInnerWindow;
int left = cols / 8;
int top = rows / 8;
int width = cols * 3 / 4;
int height = rows * 3 / 4;
switch (Cur_State) {
case 1:
//灰化处理
Imgproc.cvtColor(inputFrame.gray(), mRgba, Imgproc.COLOR_GRAY2RGBA, 4);
break;
case 2:
//Canny边缘检测
mRgba = inputFrame.rgba();
Imgproc.Canny(inputFrame.gray(), mTmp, 80, 100);
Imgproc.cvtColor(mTmp, mRgba, Imgproc.COLOR_GRAY2RGBA, 4);
break;
case 3:
//Hist直方图计算
Mat hist = new Mat();
int thikness = (int) (sizeRgba.width / (mHistSizeNum + 10) / 5);
if (thikness > 5) thikness = 5;
int offset = (int) ((sizeRgba.width - (5 * mHistSizeNum + 4 * 10) * thikness) / 2);
// RGB
for (int c = 0; c < 3; c++) {
Imgproc.calcHist(Arrays.asList(mRgba), mChannels[c], mMat0, hist, mHistSize, mRanges);
Core.normalize(hist, hist, sizeRgba.height / 2, 0, Core.NORM_INF);
hist.get(0, 0, mBuff);
for (int h = 0; h < mHistSizeNum; h++) {
mP1.x = mP2.x = offset + (c * (mHistSizeNum + 10) + h) * thikness;
mP1.y = sizeRgba.height - 1;
mP2.y = mP1.y - 2 - (int) mBuff[h];
Imgproc.line(mRgba, mP1, mP2, mColorsRGB[c], thikness);
}
}
// Value and Hue
Imgproc.cvtColor(mRgba, mTmp, Imgproc.COLOR_RGB2HSV_FULL);
// Value
Imgproc.calcHist(Arrays.asList(mTmp), mChannels[2], mMat0, hist, mHistSize, mRanges);
Core.normalize(hist, hist, sizeRgba.height / 2, 0, Core.NORM_INF);
hist.get(0, 0, mBuff);
for (int h = 0; h < mHistSizeNum; h++) {
mP1.x = mP2.x = offset + (3 * (mHistSizeNum + 10) + h) * thikness;
mP1.y = sizeRgba.height - 1;
mP2.y = mP1.y - 2 - (int) mBuff[h];
Imgproc.line(mRgba, mP1, mP2, mWhilte, thikness);
}
break;
case 4:
//Sobel边缘检测
Mat gray = inputFrame.gray();
Mat grayInnerWindow = gray.submat(top, top + height, left, left + width);
rgbaInnerWindow = mRgba.submat(top, top + height, left, left + width);
Imgproc.Sobel(grayInnerWindow, mIntermediateMat, CvType.CV_8U, 1, 1);
Core.convertScaleAbs(mIntermediateMat, mIntermediateMat, 10, 0);
Imgproc.cvtColor(mIntermediateMat, rgbaInnerWindow, Imgproc.COLOR_GRAY2BGRA, 4);
grayInnerWindow.release();
rgbaInnerWindow.release();
break;
case 5:
//SEPIA(色调变换)
rgbaInnerWindow = mRgba.submat(top, top + height, left, left + width);
Core.transform(rgbaInnerWindow, rgbaInnerWindow, mSepiaKernel);
rgbaInnerWindow.release();
break;
case 6:
//ZOOM放大镜
Mat zoomCorner = mRgba.submat(0, rows / 2 - rows / 10, 0, cols / 2 - cols / 10);
Mat mZoomWindow = mRgba.submat(rows / 2 - 9 * rows / 100, rows / 2 + 9 * rows / 100, cols / 2 - 9 * cols / 100, cols / 2 + 9 * cols / 100);
Imgproc.resize(mZoomWindow, zoomCorner, zoomCorner.size());
Size wsize = mZoomWindow.size();
Imgproc.rectangle(mZoomWindow, new Point(1, 1), new Point(wsize.width - 2, wsize.height - 2), new Scalar(255, 0, 0, 255), 2);
zoomCorner.release();
mZoomWindow.release();
break;
case 7:
//PIXELIZE像素化
rgbaInnerWindow = mRgba.submat(top, top + height, left, left + width);
Imgproc.resize(rgbaInnerWindow, mIntermediateMat, mSize0, 0.1, 0.1, Imgproc.INTER_NEAREST);
Imgproc.resize(mIntermediateMat, rgbaInnerWindow, rgbaInnerWindow.size(), 0., 0., Imgproc.INTER_NEAREST);
rgbaInnerWindow.release();
break;
default:
//显示原图
mRgba = inputFrame.rgba();
break;
}
//返回处理后的结果数据
return mRgba;
}
}
其中，使用前置摄像头，可以调用JavaCameraView组件的
setCameraIndex(CameraBridgeViewBase.CAMERA_ID_FRONT);方法。
这里进行图像预览时，会出现图像旋转的问题，使用后置摄像头的旋转问题，可以看之前的这篇文章：
OpenCV4Android中图像预览旋转90度的问题
前置的旋转方向不一样，还做摸索中。
本文代码主要参考了这篇文章OpenCV学习笔记（七）—— OpenCV for Android实时图像处理