使用camera2 API获取单个图像并使用ImageView显示 [英] Using camera2 API to get single image and display it with ImageView

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本文介绍了使用camera2 API获取单个图像并使用ImageView显示的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我想使用Camera2 API从相机中获取一帧并用ImageView显示它.我发现了一些紧密的问题，例如

I want to use Camera2 API to get a single frame from the camera and display it with ImageView. I found some close questions such as

https://stackoverflow.com/questions/25462277/camera-preview-image-data-processing-with-android-l-and-camera2-api

我也看了Camera2Basic示例，但是它太复杂了，并不是我真正需要的.

And also I've looked at Camera2Basic example but it was too complex and not exactly what I needed.

我写的代码是基于我在网上看到的一些示例，应该可以执行，但是它不起作用，我不知道为什么.

I wrote the code, that is based on some examples I saw on the web, that should do it but it doesn't work and I can't figure out why.

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，以尝试使logcat保持清晰.

The app doesn't crash but simply doesn't display any content on the ImageView. I used Log messages in any function call in order to try and keep the logcat clear.

另外，该应用程序是logcat的，它说:该应用程序可能在后台做过多的工作.."我看不到这是怎么回事，因为我只做了一个 captureRequest 而不是 repeatingCaptureRequest .

Also, the app is logcat says that "the application may be doing too much work on the background.." I don't see how is it possible because I made a single captureRequest and not a repeatingCaptureRequest.

这是代码和日志记录器:代码:

Here's the code and the logcat: Code:

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();
}

(相关的)logcat:

And the (relevant) 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: android.os.BinderProxy@13c07070 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

谢谢，诺姆

推荐答案

由于这个问题有点老了，不确定它是否仍然是热门话题，但我会尽力回答.

As this question is a bit old, not sure if it's still topical, but I'll try to answer.

您正在创建 ImageRader 的实例，即 ImageReader.OnImageAvailableListener ，但未将侦听器分配给您拥有的imageReader实例.

You are creating an instance of ImageRader, an ImageReader.OnImageAvailableListener, but not assigning your listener to the imageReader instance you have.

在您的 setupCamera 方法中，实例化一个新的ImageReader之后，将侦听器设置为它:

In your setupCamera method, after instantiating a new ImageReader, set the listener to it:

/**
 * 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);
    // this line is missing
    imageReader.setOnImageAvailableListener(imageReaderListener, handler);
...

希望这对您或其他人尝试您的代码作为示例有帮助.

Hope this helps you, or someone else trying out your code as a sample.

这篇关于使用camera2 API获取单个图像并使用ImageView显示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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