[英]How can I best detect different LED colours using an Android phone's camera and OpenCV?
[英]Using android phone camera in opencv?
是否可以通過USB電纜將手機連接到計算機並將其用作網絡攝像頭? 我知道有很多允許它的軟件(至少對於無線而言),但是如何在opencv中使用它(我正在使用Java)?
我認為有可能,但是我沒有對其進行測試。 首先下載一個這樣的應用程序,該應用程序可以將您的手機用作網絡攝像頭,如果它是系統上唯一的網絡攝像頭,則可以通過VideoCapture(0)連接到該應用程序。 這段代碼應該可以很好地進行測試,如果一切正常,您應該在JFrame中看到視頻:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.awt.image.WritableRaster;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.InputStream;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import org.opencv.core.*;
import org.opencv.highgui.Highgui;
import org.opencv.highgui.VideoCapture;
public class JPanelOpenCV extends JPanel{
BufferedImage image;
public static void main (String args[]) throws InterruptedException{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
JPanelOpenCV t = new JPanelOpenCV();
VideoCapture camera = new VideoCapture(0);
Mat frame = new Mat();
camera.read(frame);
if(!camera.isOpened()){
System.out.println("Error");
}
else {
while(true){
if (camera.read(frame)){
BufferedImage image = t.MatToBufferedImage(frame);
t.window(image, "Original Image", 0, 0);
t.window(t.grayscale(image), "Processed Image", 40, 60);
//t.window(t.loadImage("ImageName"), "Image loaded", 0, 0);
break;
}
}
}
camera.release();
}
@Override
public void paint(Graphics g) {
g.drawImage(image, 0, 0, this);
}
public JPanelOpenCV() {
}
public JPanelOpenCV(BufferedImage img) {
image = img;
}
//Show image on window
public void window(BufferedImage img, String text, int x, int y) {
JFrame frame0 = new JFrame();
frame0.getContentPane().add(new JPanelOpenCV(img));
frame0.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame0.setTitle(text);
frame0.setSize(img.getWidth(), img.getHeight() + 30);
frame0.setLocation(x, y);
frame0.setVisible(true);
}
//Load an image
public BufferedImage loadImage(String file) {
BufferedImage img;
try {
File input = new File(file);
img = ImageIO.read(input);
return img;
} catch (Exception e) {
System.out.println("erro");
}
return null;
}
//Save an image
public void saveImage(BufferedImage img) {
try {
File outputfile = new File("Images/new.png");
ImageIO.write(img, "png", outputfile);
} catch (Exception e) {
System.out.println("error");
}
}
//Grayscale filter
public BufferedImage grayscale(BufferedImage img) {
for (int i = 0; i < img.getHeight(); i++) {
for (int j = 0; j < img.getWidth(); j++) {
Color c = new Color(img.getRGB(j, i));
int red = (int) (c.getRed() * 0.299);
int green = (int) (c.getGreen() * 0.587);
int blue = (int) (c.getBlue() * 0.114);
Color newColor =
new Color(
red + green + blue,
red + green + blue,
red + green + blue);
img.setRGB(j, i, newColor.getRGB());
}
}
return img;
}
public BufferedImage MatToBufferedImage(Mat frame) {
//Mat() to BufferedImage
int type = 0;
if (frame.channels() == 1) {
type = BufferedImage.TYPE_BYTE_GRAY;
} else if (frame.channels() == 3) {
type = BufferedImage.TYPE_3BYTE_BGR;
}
BufferedImage image = new BufferedImage(frame.width(), frame.height(), type);
WritableRaster raster = image.getRaster();
DataBufferByte dataBuffer = (DataBufferByte) raster.getDataBuffer();
byte[] data = dataBuffer.getData();
frame.get(0, 0, data);
return image;
}
}
附言:我確實認為您的問題也是題外話。
您可以簡單地創建攝像機活動並編寫給定的代碼
package com.techamongus.opencvcamera;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.JavaCameraView;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import java.io.File;
import java.util.List;
public class CameraActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2 {
// A tag for log output.
private static final String TAG =
CameraActivity.class.getSimpleName();
// A key for storing the index of the active camera.
private static final String STATE_CAMERA_INDEX = "cameraIndex";
// A key for storing the index of the active image size.
private static final String STATE_IMAGE_SIZE_INDEX =
"imageSizeIndex";
// An ID for items in the image size submenu.
private static final int MENU_GROUP_ID_SIZE = 2;
// The index of the active camera.
private int mCameraIndex;
// The index of the active image size.
private int mImageSizeIndex;
// Whether the active camera is front-facing.
// If so, the camera view should be mirrored.
private boolean mIsCameraFrontFacing;
// The number of cameras on the device.
private int mNumCameras;
// The camera view.
private CameraBridgeViewBase mCameraView;
// The image sizes supported by the active camera.
private List<Camera.Size> mSupportedImageSizes;
// Whether the next camera frame should be saved as a photo.
private boolean mIsPhotoPending;
// A matrix that is used when saving photos.
private Mat mBgr;
// Whether an asynchronous menu action is in progress.
// If so, menu interaction should be disabled.
private boolean mIsMenuLocked;
// The OpenCV loader callback.
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(final int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS:
Log.d(TAG, "OpenCV loaded successfully");
mCameraView.enableView();
mBgr = new Mat();
break;
default:
super.onManagerConnected(status);
break;
}
}
};
@SuppressLint("NewApi")
@Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final Window window = getWindow();
window.addFlags(
WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
if (savedInstanceState != null) {
mCameraIndex = savedInstanceState.getInt(
STATE_CAMERA_INDEX, 0);
mImageSizeIndex = savedInstanceState.getInt(
STATE_IMAGE_SIZE_INDEX, 0);
} else {
mCameraIndex = 0;
mImageSizeIndex = 0;
}
final Camera camera;
if (Build.VERSION.SDK_INT >=
Build.VERSION_CODES.GINGERBREAD) {
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
Camera.getCameraInfo(mCameraIndex, cameraInfo);
mIsCameraFrontFacing =
(cameraInfo.facing ==
Camera.CameraInfo.CAMERA_FACING_FRONT);
mNumCameras = Camera.getNumberOfCameras();
camera = Camera.open(mCameraIndex);
} else { // pre-Gingerbread
// Assume there is only 1 camera and it is rear-facing.
mIsCameraFrontFacing = false;
mNumCameras = 1;
camera = Camera.open();
}
final Camera.Parameters parameters = camera.getParameters();
camera.release();
mSupportedImageSizes =
parameters.getSupportedPreviewSizes();
final Camera.Size size = mSupportedImageSizes.get(mImageSizeIndex);
mCameraView = new JavaCameraView(this, mCameraIndex);
mCameraView.setMaxFrameSize(size.width, size.height);
mCameraView.setCvCameraViewListener(this);
setContentView(mCameraView);
}
public void onSaveInstanceState(Bundle savedInstanceState) {
// Save the current camera index.
savedInstanceState.putInt(STATE_CAMERA_INDEX, mCameraIndex);
// Save the current image size index.
savedInstanceState.putInt(STATE_IMAGE_SIZE_INDEX,
mImageSizeIndex);
super.onSaveInstanceState(savedInstanceState);
}
@SuppressLint("NewApi")
@Override
public void recreate() {
if (Build.VERSION.SDK_INT >=
Build.VERSION_CODES.HONEYCOMB) {
super.recreate();
} else {
finish();
startActivity(getIntent());
}
}
@Override
public void onPause() {
if (mCameraView != null) {
mCameraView.disableView();
}
super.onPause();
}
@Override
public void onResume() {
super.onResume();
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_2_0,
this, mLoaderCallback);
mIsMenuLocked = false;
}
@Override
public void onDestroy() {
if (mCameraView != null) {
mCameraView.disableView();
}
super.onDestroy();
}
public Mat onCameraFrame(final CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
final Mat rgba = inputFrame.rgba();
if (mIsPhotoPending) {
mIsPhotoPending = false;
//takePhoto(rgba);
}
if (mIsCameraFrontFacing) {
// Mirror (horizontally flip) the preview.
Core.flip(rgba, rgba, 1);
}
return rgba;
}
免責聲明:檢查我的博客鏈接http://www.techamongus.com/2017/03/android-camera-in-opencv.html
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.