Question

我必须在Google Vision API的CameraSource中实现构建相机并在捕获图像之前进行面部检测。现在我遇到了一些问题，所以我需要从CameraSource访问相机对象。

如何使用CameraSource实现增加或降低相机预览亮度？

这是我的CameraSource Builder

$ cat S13a4sed 
he is a girl
$ perl -pi -e 's/he/she/g' S13a4sed
$ cat S13a4sed
she is a girl

在这里，我必须尝试从mCameraSource对象访问/获取相机。

 mCameraSource = new CameraSource.Builder(context, detector)
                .setRequestedPreviewSize(640, 480)
                .setFacing(CameraSource.CAMERA_FACING_FRONT)
                .setRequestedFps(30.0f)
                .build();

但是Field[] declaredFields = CameraSource.class.getDeclaredFields(); for (Field field : declaredFields) { if (field.getType() == Camera.class) { field.setAccessible(true); try { Camera camera = (Camera) field.get(mCameraSource); if (camera != null) { Camera.Parameters params = camera.getParameters(); params.setExposureCompensation(1500); camera.setParameters(params); } } catch (IllegalAccessException e) { e.printStackTrace(); } } }仅返回null，而我的第二个问题是如何进行亮度选项......

camera

Answer 1

我必须像这样实现我的目标，

相机亮度等级为-12至12.因此最低亮度等级为-12，最高亮度等级为12.

现在我必须自定义CameraSourcePreview构造函数，如

private int defaultBrightness = 12;

public CameraSourcePreview(Context context, AttributeSet attrs) {
    super(context, attrs);
    mContext = context;
    mStartRequested = false;
    mSurfaceAvailable = false;

    mSurfaceView = new SurfaceView(context);
    mSurfaceView.getHolder().addCallback(new SurfaceCallback());
    addView(mSurfaceView);
    mSurfaceView.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            cameraFocus(mCameraSource, brightness);
        }
    });
}

private static boolean cameraFocus(@NonNull CameraSource cameraSource, int brightness) {
    Field[] declaredFields = CameraSource.class.getDeclaredFields();

    for (Field field : declaredFields) {
        if (field.getType() == Camera.class) {
            field.setAccessible(true);
            try {
                Camera camera = (Camera) field.get(cameraSource);
                if (camera != null) {
                    Camera.Parameters params = camera.getParameters();
                        params.setExposureCompensation(brightness);
                    camera.setParameters(params);
                    return true;
                }

                return false;
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }

            break;
        }
    }

    return false;
}

然后我必须通过搜索栏实现动态亮度调整。

像

seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {


                cameraFocus(mCameraSource,i-12);
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
            }
        });

seekbar xml代码

<SeekBar
            android:id="@+id/seekBar1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:max="24"
            android:layout_gravity="center_vertical"/>

最后，我得到了解决方案...... :)

从com.google.android.gms.vision.CameraSource访问相机并增加/减少预览亮度

1 个答案: