使用camera2 API获取单个图像并使用ImageView显示
问题描述：
我想使用Camera2 API从摄像机获取单帧并使用ImageView显示它。 我发现了一些问题，近如使用camera2 API获取单个图像并使用ImageView显示
同时，我已经看了Camera2Basic的例子，但它太复杂，不正是我需要的。
我编写了代码，这是基于我在网上看到的一些例子，应该这样做，但它不工作，我不明白为什么。
该应用程序不会崩溃，但不会在ImageView上显示任何内容。 我在任何函数调用中都使用了Log消息，以尝试保持logcat清晰。
此外，该应用程序是logcat说，“该应用程序可能在背景上做了太多的工作..”我不明白怎么可能，因为我做了一个captureRequest而不是repeatingCaptureRequest。
下面的代码和logcat的： 代码：
public class CameraImageReaderActivity extends AppCompatActivity {
private final static String TAG = "CAMERA_IMAGE_READY: ";
private ImageReader imageReader;
private String cameraId;
private CameraDevice camera;
private HandlerThread handlerThread;
private Handler handler;
private Surface imageReaderSurface;
private ImageView imageView;
private CameraDevice.StateCallback cameraStateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice cameraDevice) {
Log.d(TAG, "onOpend: CAMERA OPENED");
camera = cameraDevice;
getFrames();
}
@Override
public void onDisconnected(CameraDevice cameraDevice) {
Log.d(TAG, "onDisconnected: CAMERA DISCONNECTED");
cameraDevice.close();
camera = null;
}
@Override
public void onError(CameraDevice cameraDevice, int i) {
Log.d(TAG, "onError: CAMERA ERROR");
cameraDevice.close();
camera = null;
}
};
private CameraCaptureSession.StateCallback captureSessionStateCallback = new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession cameraCaptureSession) {
Log.d(TAG, "onConfigured: build request and capture");
try {
CaptureRequest.Builder requestBuilder = cameraCaptureSession.getDevice().createCaptureRequest(CameraDevice.TEMPLATE_RECORD);
requestBuilder.addTarget(imageReaderSurface);
cameraCaptureSession.capture(requestBuilder.build(), null, handler);
} catch (CameraAccessException e) {
Log.d(TAG, "onConfigured: CANT CREATE CAPTURE REQUEST");
e.printStackTrace();
}
}
@Override
public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) {
Log.d(TAG, "onConfiguredFailed: CANT CONFIGURE CAMERA");
}
};
private ImageReader.OnImageAvailableListener imageReaderListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader imageReader) {
Log.d(TAG, "onImageAvailable: IMAGE AVAILABLE");
Image image = imageReader.acquireLatestImage();
int imgFormat = image.getFormat();
ByteBuffer pixelArray1 = image.getPlanes()[0].getBuffer();
int pixelStride = image.getPlanes()[0].getPixelStride();
int rowStride = image.getPlanes()[0].getRowStride();
int rowPadding = rowStride - pixelStride * 640;
Bitmap bitmap = Bitmap.createBitmap(640 + rowPadding/pixelStride, 480, Bitmap.Config.RGB_565);
bitmap.copyPixelsFromBuffer(pixelArray1);
imageView.setImageBitmap(bitmap);
image.close();
}
};
/**
* Sets the cameraId with the front camera id and sets imageReader properties.
*/
public void setupCamera(int width, int height) {
imageReader = ImageReader.newInstance(width, height, ImageFormat.RGB_565, 30);
CameraManager cameraManager = (CameraManager) getSystemService(CAMERA_SERVICE);
try {
for (String allCamerasId : cameraManager.getCameraIdList()) {
CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(allCamerasId);
if (cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT) {
continue;
}
cameraId = allCamerasId;
Log.d(TAG, "setupCamera: CameraId is: " + cameraId);
return;
}
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
/**
* Connects to the front facing camera.
* After the connection to the camera, the onOpened callback method will be invoked.
*/
public void connectCamera() {
CameraManager cameraManager = (CameraManager) getSystemService(CAMERA_SERVICE);
try {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "CANT OPEN CAMERA");
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
cameraManager.openCamera(cameraId, cameraStateCallback, handler);
Log.d(TAG, "connectCamera: CAMERA OPENED!");
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
/**
* Build the captureSessionRequest and start in repeat.
*/
public void getFrames() {
Log.d(TAG, "getFrames: CREATE CAPTURE SESSION");
imageReaderSurface = imageReader.getSurface();
List<Surface> surfaceList = new ArrayList<>();
surfaceList.add(imageReaderSurface);
try {
camera.createCaptureSession(surfaceList, captureSessionStateCallback, handler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
public void startBackgroundThread() {
handlerThread = new HandlerThread("CameraImageReaderActivity");
handlerThread.start();
handler = new Handler(handlerThread.getLooper());
}
public void stopBackgroundThread() {
handlerThread.quitSafely();
try {
handlerThread.join();
handlerThread = null;
handler = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void closeCamera() {
if (camera != null) {
camera.close();
camera = null;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera_image_reader);
imageView = (ImageView) findViewById(R.id.imageView);
setupCamera(640, 480);
connectCamera();
}
@Override
protected void onPause() {
closeCamera();
startBackgroundThread();
super.onPause();
}
@Override
protected void onResume() {
super.onResume();
startBackgroundThread();
//connectCamera();
}
而且（相关）的logcat：
03-22 14:27:32.900 18806-18806/com.example.noamm_000.talkwithcompviawifi D/CAMERA_IMAGE_READY:: setupCamera: CameraId is: 0
03-22 14:27:32.904 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value mw_continuous-picture
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value emboss
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value sketch
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value neon
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value asd
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value backlight
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value flowers
03-22 14:27:32.905 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value AR
03-22 14:27:32.912 18806-18806/com.example.noamm_000.talkwithcompviawifi I/CameraManager: Using legacy camera HAL.
03-22 14:27:33.685 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value mw_continuous-picture
03-22 14:27:33.685 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value emboss
03-22 14:27:33.685 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value sketch
03-22 14:27:33.685 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value neon
03-22 14:27:33.686 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value asd
03-22 14:27:33.686 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value backlight
03-22 14:27:33.686 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value flowers
03-22 14:27:33.686 18806-18806/com.example.noamm_000.talkwithcompviawifi W/ArrayUtils: Ignoring invalid value AR
03-22 14:27:33.702 18806-18806/com.example.noamm_000.talkwithcompviawifi D/CAMERA_IMAGE_READY:: connectCamera: CAMERA OPENED!
03-22 14:27:33.719 18806-18806/com.example.noamm_000.talkwithcompviawifi I/Choreographer: Skipped 56 frames! The application may be doing too much work on its main thread.
03-22 14:27:33.787 18806-18806/com.example.noamm_000.talkwithcompviawifi D/CAMERA_IMAGE_READY:: onOpend: CAMERA OPENED
03-22 14:27:33.787 18806-18806/com.example.noamm_000.talkwithcompviawifi D/CAMERA_IMAGE_READY:: getFrames: CREATE CAPTURE SESSION
03-22 14:27:33.789 18806-18806/com.example.noamm_000.talkwithcompviawifi I/CameraDeviceState: Legacy camera service transitioning to state CONFIGURING
03-22 14:27:33.789 18806-19149/com.example.noamm_000.talkwithcompviawifi I/RequestThread-0: Configure outputs: 1 surfaces configured.
03-22 14:27:33.790 18806-19149/com.example.noamm_000.talkwithcompviawifi D/Camera: app passed NULL surface
03-22 14:27:33.838 18806-18806/com.example.noamm_000.talkwithcompviawifi I/CameraDeviceState: Legacy camera service transitioning to state IDLE
03-22 14:27:33.843 18806-19150/com.example.noamm_000.talkwithcompviawifi D/CAMERA_IMAGE_READY:: onConfigured: build request and capture
03-22 14:27:33.874 18806-19149/com.example.noamm_000.talkwithcompviawifi W/LegacyRequestMapper: convertRequestMetadata - control.awbRegions setting is not supported, ignoring value
03-22 14:27:33.875 18806-19149/com.example.noamm_000.talkwithcompviawifi W/LegacyRequestMapper: Only received metering rectangles with weight 0.
03-22 14:27:33.875 18806-19149/com.example.noamm_000.talkwithcompviawifi W/LegacyRequestMapper: Only received metering rectangles with weight 0.
03-22 14:27:34.070 18806-18806/com.example.noamm_000.talkwithcompviawifi I/Timeline: Timeline: Activity_idle id: [email protected] time:331143683
03-22 14:27:34.317 18806-19155/com.example.noamm_000.talkwithcompviawifi I/CameraDeviceState: Legacy camera service transitioning to state CAPTURING
03-22 14:27:34.353 18806-19149/com.example.noamm_000.talkwithcompviawifi I/CameraDeviceState: Legacy camera service transitioning to state IDLE
03-22 14:27:34.403 18806-18806/com.example.noamm_000.talkwithcompviawifi D/BubblePopupHelper: isShowingBubblePopup : false
03-22 14:27:34.403 18806-18806/com.example.noamm_000.talkwithcompviawifi D/BubblePopupHelper: isShowingBubblePopup : false
03-22 14:27:34.404 18806-18806/com.example.noamm_000.talkwithcompviawifi D/BubblePopupHelper: isShowingBubblePopup : false
03-22 14:27:34.404 18806-18806/com.example.noamm_000.talkwithcompviawifi D/BubblePopupHelper: isShowingBubblePopup : false
03-22 14:28:07.684 18806-18823/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.684 18806-18822/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.684 18806-19184/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.685 18806-18823/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.685 18806-18822/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.685 18806-19184/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.686 18806-18823/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
03-22 14:28:07.686 18806-18822/com.example.noamm_000.talkwithcompviawifi E/BufferQueueProducer: [unnamed-18806-1] cancelBuffer: BufferQueue has been abandoned
感谢， 诺姆
答
尝试这种方式更好地处理它在后台线程。
public void onImageAvailable(ImageReader reader) {
new ImageSaver(reader.acquireLatestImage());
}
private class ImageSaver implements Runnable {
private final Image mImage;
public ImageSaver(Image image) {
mImage = image;
}
@Override
public void run() {
File mImageFileName = null;
if (mImage != null) {
ByteBuffer byteBuffer = mImage.getPlanes()[0].getBuffer();
byte[] bytes = new byte[byteBuffer.remaining()];
byteBuffer.get(bytes);
FileOutputStream fileOutputStream = null;
try {
mImageFileName = createImageFileName();
fileOutputStream = new FileOutputStream(mImageFileName);
fileOutputStream.write(bytes);
} catch (IOException e) {
e.printStackTrace();
} finally {
mImage.close();
if (mImageFileName != null) {
Intent mediaStoreUpdateIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
mediaStoreUpdateIntent.setData(Uri.fromFile(mImageFileName));
sendBroadcast(mediaStoreUpdateIntent);
loadImageFromStorage(mImageFileName);
}
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
private void loadImageFromStorage(File mImageFileName) {
imageView.setImageBitmap(BitmapFactory.decodeFile(mImageFileName.getAbsolutePath()));
}
}
private File createImageFileName() throws IOException {
String timestamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String prepend = "IMAGE_" + timestamp + "_";
File imageFile = File.createTempFile(prepend, ".jpg", createImageFolder());
return imageFile;
}
private File createImageFolder() {
File imageFile = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File mImageFolder = new File(imageFile, "myFolder");
if (!mImageFolder.exists()) {
mImageFolder.mkdirs();
}
return mImageFolder;
}
答
是RGB_565列为该相机设备支持的格式，从CameraManager.getCameraCharacteristics（ID）获得（CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP）.getOutputFormats（）？
如果没有，这通常不起作用，但它应该给你一个会话创建失败。唯一可以支持的格式是ImageFormat.JPEG和ImageFormat.YUV_420_888。
前者可能更容易处理（尽管效率稍差） - 将JPEG平面[0] ByteBuffer复制到byte []中，并使用BitmapFactory.decodeByteArray（）从中创建一个位图来显示。
对于您的具体情况，您似乎永远不会调用imageReader.setOnImageAvailableListener（imageReaderListener），因此您无法获得有关捕获的缓冲区的通知。
编辑：，并有 此外，从摄像头接收的前几个图像可能会被严重暴露（如果你在光线昏暗的位置是可能是全黑）差白平衡，对焦等在拍摄最终图像之前，您需要让相机运行几个画面，以便它可以调整自动曝光/对焦等等以正确的值。
通常，使用带有TEMPLATE_PREVIEW的重复请求并等待，直到在捕获结果中看到至少CONTROL_AE_STATE_CONVERGED为止是个好主意;这仍然会将焦点留在潜在的糟糕状态，但是您是否想要处理焦点取决于用例和输出分辨率。
谢谢你的回答，但你有没有测试过你的代码？它包含一些错误，我也不需要将帧保存在手机存储器中，我只想在imageView .. – Noam
上显示它的简单想法，您可以从byte []创建位图而不保存它。 –