I'm working on Android and I'm trying to capture a picture without displaying any preview. I tried to simplify the process by making a class. It's working but all the pictures are really really dark. Here is my class :
public class Cam {
private Context context;
private CameraManager manager;
private CameraDevice camera;
private CameraCaptureSession session;
private ImageReader reader;
public static String FRONT="-1";
public static String BACK="-1";
private boolean available=true;
private String filepath;
private static final String NO_CAM = "No camera found on device!";
private static final String ERR_CONFIGURE = "Failed configuring session";
private static final String ERR_OPEN = "Can't open the camera";
private static final String CAM_DISCONNECT = "Camera disconnected";
private static final String FILE_EXIST = "File already exist";
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
static {
ORIENTATIONS.append(Surface.ROTATION_0, 90);
ORIENTATIONS.append(Surface.ROTATION_90, 0);
ORIENTATIONS.append(Surface.ROTATION_180, 270);
ORIENTATIONS.append(Surface.ROTATION_270, 180);
}
public Cam(Context context) throws CameraAccessException {
this.context = context;
this.manager = (CameraManager) context.getSystemService(Context.CAMERA_SERVICE);
String ids[] = manager.getCameraIdList();
if(ids.length==2){
BACK=ids[0];
FRONT=ids[1];
}
else if(ids.length==1){
BACK=ids[0];
}
else{
available=false;
throw new CameraAccessException(-1, NO_CAM);
}
}
public void takePicture(String camId, String filepath) throws CameraAccessException {
if(available){
this.filepath=filepath;
StreamConfigurationMap map = manager.getCameraCharacteristics(camId).get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
Size largest = Collections.max(Arrays.asList(map.getOutputSizes(ImageFormat.JPEG)), new CompareSizesByArea());
reader=ImageReader.newInstance(largest.getWidth(), largest.getHeight(), ImageFormat.JPEG, 1);
reader.setOnImageAvailableListener(imageListener, null);
manager.openCamera(camId, cameraStateCallback, null);
}
else
throwError(NO_CAM);
}
private CameraDevice.StateCallback cameraStateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
Cam.this.camera=camera;
try {
camera.createCaptureSession(Collections.singletonList(reader.getSurface()), sessionStateCallback, null);
} catch (CameraAccessException e) {
throwError(e.getMessage());
}
}
@Override
public void onDisconnected(CameraDevice camera) {
throwError(CAM_DISCONNECT);
}
@Override
public void onError(CameraDevice camera, int error) {
throwError(ERR_OPEN);
}
};
private CameraCaptureSession.StateCallback sessionStateCallback = new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
Cam.this.session=session;
try {
CaptureRequest.Builder request = camera.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
request.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
request.addTarget(reader.getSurface());
int rotation = ((WindowManager)context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getRotation();
request.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));
session.capture(request.build(), captureCallback, null);
} catch (CameraAccessException e) {
throwError(e.getMessage());
}
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
throwError(ERR_CONFIGURE);
}
};
private CameraCaptureSession.CaptureCallback captureCallback = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureFailed(CameraCaptureSession session, CaptureRequest request, CaptureFailure failure) {
super.onCaptureFailed(session, request, failure);
throwError(failure.toString());
}
};
private ImageReader.OnImageAvailableListener imageListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
Image image = reader.acquireLatestImage();
try {
File file = saveImage(image);
// Send file via a listener
closeCamera();
} catch (IOException e) {
throwError(e.getMessage());
}
reader.close();
}
};
private File saveImage(Image image) throws IOException {
File file = new File(filepath);
if (file.exists()) {
throwError(FILE_EXIST);
return null;
}
else {
ByteBuffer buffer = image.getPlanes()[0].getBuffer();
byte[] bytes = new byte[buffer.remaining()];
buffer.get(bytes);
FileOutputStream output = new FileOutputStream(file);
output.write(bytes);
image.close();
output.close();
return file;
}
}
static class CompareSizesByArea implements Comparator<Size> {
@Override
public int compare(Size lhs, Size rhs) {
return Long.signum((long) lhs.getWidth() * lhs.getHeight() - (long) rhs.getWidth() * rhs.getHeight());
}
}
private void closeCamera(){
if(session!=null) {session.close();}
if(reader!=null) {reader.close();}
if(camera!=null) {camera.close();}
}
Then I call the Cam object in my Activity :
Cam cam = new Cam(MainActivity.this);
cam.takePicture(Cam.BACK, "/sdcard/pic.jpg");
A listener prevent the MainActivity when the picture is available, but I removed the code to clear a bit.
I don't know what I am doing wrong, the pictures are really dark. Maybe a flag or something... Any help will be appreciated.
EDIT: Working class : https://github.com/omaflak/Android-Camera2-Library/blob/master/ezcam/src/main/java/me/aflak/ezcam/EZCam.java
Example: https://github.com/omaflak/Android-Camera2-Library/blob/master/app/src/main/java/me/aflak/libraries/MainActivity.java
