在 android camera2API 中控制传感器 ISO 和曝光时间

Question

我正在尝试在手动相机控制中添加新的曝光值和 ISO 值。我正在使用 Camera2Basic 示例。我现在面临的问题是我是Android的新手。我尝试查看 L-Camera，但它在 Scala 中，这让我更加困惑。

我尝试了以下更改，但图像预览没有更新。

 private void createCameraPreviewSession() {
    try {
        SurfaceTexture texture = mTextureView.getSurfaceTexture();
        assert texture != null;

        // We configure the size of default buffer to be the size of camera preview we want.
        texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());

        // This is the output Surface we need to start preview.
        Surface surface = new Surface(texture);

        // We set up a CaptureRequest.Builder with the output Surface.
        mPreviewRequestBuilder
                = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        mPreviewRequestBuilder.addTarget(surface);

        // Here, we create a CameraCaptureSession for camera preview.
        mCameraDevice.createCaptureSession(Arrays.asList(surface, mImageReader.getSurface()),
                new CameraCaptureSession.StateCallback() {

                    @Override
                    public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                        // The camera is already closed
                        if (null == mCameraDevice) {
                            return;
                        }

                        // When the session is ready, we start displaying the preview.
                        mCaptureSession = cameraCaptureSession;
                        try {
                            // Auto focus should be continuous for camera preview.
                            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,
                                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);

                            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE,
                                    CaptureRequest.CONTROL_AE_MODE_OFF);

                            mPreviewRequestBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME,Long.valueOf("100000"));
                            mPreviewRequestBuilder.set(CaptureRequest.SENSOR_SENSITIVITY,1600);

                            // Flash is automatically enabled when necessary.
                            setAutoFlash(mPreviewRequestBuilder);

                            // Finally, we start displaying the camera preview.
                            mPreviewRequest = mPreviewRequestBuilder.build();
                            mCaptureSession.setRepeatingRequest(mPreviewRequest,
                                    mCaptureCallback, mBackgroundHandler);
                        } catch (CameraAccessException e) {
                            e.printStackTrace();
                        }
                    }

                    @Override
                    public void onConfigureFailed(
                            @NonNull CameraCaptureSession cameraCaptureSession) {
                        showToast("Failed");
                    }
                }, null
        );
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

Answer 1

首先，您必须将模板更改为 TEMPLATE_STILL_CAPTURE 或 TEMPLATE_MANUAL 才能在预览中看到值的变化。另外，记得将 CONTROL_AE_MODE 和 'CONTROL_MODE' 设置为关闭。

This control is only effective if android.control.aeMode or android.control.mode is set to OFF; otherwise the auto-exposure algorithm will override this value.

来自Android Developer

其次，设置您的价值观：

builder.set(CaptureRequest.SENSOR_SENSITIVITY, isoValue);
builder.set(CaptureRequest.SENSOR_EXPOSURE_TIME, exposureTimeValueInMilliseconds);

最后，在所有更改之后不要忘记使用 CaptureSession.setRepeatingRequest

更新您的预览

希望对您有所帮助！

Answer 2

所以我对我的代码进行了以下更改。

mPreviewRequestBuilder
    = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_MANUAL);
mPreviewRequestBuilder.addTarget(surface);


mPreviewRequestBuilder.set(CaptureRequest.CONTROL_MODE,
    CaptureRequest.CONTROL_MODE_OFF);

mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,
    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);

mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE,
    CaptureRequest.CONTROL_AE_MODE_OFF);

mPreviewRequestBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME,Long.valueOf("22000"));
mPreviewRequestBuilder.set(CaptureRequest.SENSOR_SENSITIVITY,200);

mCaptureSession.setRepeatingRequest(mPreviewRequest,
    mCaptureCallback, mBackgroundHandler);

但是我得到了一个奇怪的预览，其中有很多绿光作为输入。

这里是https://postimg.org/image/yl95e6qht/

这是使用我的内置相机应用程序时的样子：https://postimg.org/image/lvjnwquj5/

Answer 3

这将解决问题：

mPreviewBuilder.set(
    CaptureRequest.CONTROL_AWB_MODE, 
    CaptureRequest.CONTROL_AWB_MODE_AUTO
);

Answer 4

我在相机 2 API 上使用手动曝光时也遇到了绿色捕捉问题。我可以通过只停用 CONTROL_AE_MODE 而不是同时停用 CONTROL_AE_MODE 和 CONTROL_MODE 来修复它。这是我的配置：

final CaptureRequest.Builder captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);

captureBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraCharacteristics.CONTROL_AE_MODE_OFF);
captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraCharacteristics.CONTROL_MODE_AUTO);
captureBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME, Long.valueOf("8000000")); // 8000000 ns = 8 ms

在 android camera2API 中控制传感器 ISO 和曝光时间

Controlling Sensor ISO and Exposure time in android camera2API

android

android-camera

android-camera2