Question

我正在使用最低API级别16的Android应用程序工作。我必须为实时帧构建自定义的Camera Builder，并为OCR处理它们。我已经设置了表面视图并添加了预览回调，以便可以实时运行框架上 onPreviewFrame（byte [] bytes，Camera camera）方法。

默认情况下，屏幕处于横向模式，并且在大多数设备中我都获得正确的方向。 但是在某些设备中，这种方法使图像旋转了180度，但无法处理。

Display display = ((WindowManager) Objects.requireNonNull(context.getSystemService(WINDOW_SERVICE))).getDefaultDisplay();
return display.getRotation();

以上方法在两个设备中均返回90度旋转。但是一方面，图像具有正确的方向，另一方面，图像旋转了180度。这是相机类：

public abstract class Camera {

    private static android.hardware.Camera mCamera;


/**
 * A safe way to get an instance of the Camera object.
 */


private static android.hardware.Camera getCameraInstance(int cameraFacing) {
    android.hardware.Camera c = null;
    try {
        c = android.hardware.Camera.open(cameraFacing); // attempt to get a Camera instance
    } catch (Exception e) {
        // Camera is not available (in use or does not exist)
    }
    return c; // returns null if camera is unavailable
}


public static void closeCamera() {
    if (mCamera != null) {
        mCamera.release();
        mCamera = null;
    }

}

public static void autoFocus() {
    if (mCamera != null)
        try {
            mCamera.autoFocus(null);
        } catch (Exception ignored) {

        }
}


/**
 * focusMode: android.hardware.Camera.Parameters
 * cameraFacing: android.hardware.Camera.CameraInfo.FACING_FRONT or FACING_BACK
 */
public static class CameraBuilder {
    private static final String TAG = CameraBuilder.class.getSimpleName();
    private String focusMode = android.hardware.Camera.Parameters.FOCUS_MODE_AUTO;
    private int cameraFacing = android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK;
    private int displayOrientation = 0;

    public CameraBuilder() {

    }

    /**
     * @param focusMode default: android.hardware.Camera.Parameters.FOCUS_MODE_AUTO
     * @return CameraBuilder
     */
    public CameraBuilder setFocusMode(String focusMode) {
        this.focusMode = focusMode;
        return this;
    }

    /**
     * @param cameraFacing default : android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK
     * @return CameraBuilder
     */
    public CameraBuilder setCameraFacing(int cameraFacing) {
        this.cameraFacing = cameraFacing;
        return this;
    }


    public CameraBuilder setDisplayOrientation(int orientation) {
        this.displayOrientation = orientation;
        return this;
    }

    public android.hardware.Camera build() {
        try {
            mCamera = getCameraInstance(cameraFacing);
            android.hardware.Camera.Parameters params = mCamera.getParameters();
            params.setFocusMode(focusMode);
            mCamera.setParameters(params);

        } catch (Exception e) {
            // Camera is not available (in use or does not exist)
            Log.e(TAG, "Camera Exception: " + e.getMessage());
        }
        mCamera.setDisplayOrientation(displayOrientation);
        return mCamera;
    }

}

}

这是我的相机的初始化。

camera = new CameraBuilder()
           .setCameraFacing(Camera.CameraInfo.CAMERA_FACING_BACK)
           .setFocusMode(android.hardware.Camera.Parameters.FOCUS_MODE_AUTO)
           .setDisplayOrientation(0)
           .build();

onPreviewFrame返回在某些设备中旋转180度的图像

0 个答案: