相機應用中的相機圖片方向

Question

使用相機API拍照時，我遇到圖片定位問題，這很常見，並且有一個常見的解決方案：

mRotation = getRotation();
mCamera.setDisplayOrientation(mRotation);

Camera.Parameters parameters = mCamera.getParameters();
parameters.setRotation(mRotation);
mCamera.setParameters(parameters);

但是此解決方案不適用於所有設備，並且圖片的方向錯誤。 為了解決這個問題，我在拍照后刪除了第二部分並將旋轉校正移至：

private static class SaveImageTask extends AsyncTask<byte[], Void, Void>
{
    private WeakReference<CameraActivity> mActivityWeakReference;

    SaveImageTask(CameraActivity cameraActivity)
    {
        mActivityWeakReference = new WeakReference<>(cameraActivity);
    }

    @Override
    protected Void doInBackground(byte[]... params)
    {
        CameraActivity cameraActivity = mActivityWeakReference.get();
        if (cameraActivity == null || cameraActivity.isFinishing())
            return null;

        Bitmap source = BitmapFactory.decodeByteArray(params[0], 0, params[0].length);

        if (source == null)
        {
            Toast.makeText(cameraActivity, "Captured image is empty", Toast.LENGTH_LONG).show();
            return null;
        }

        Matrix matrix = new Matrix();
        matrix.postRotate(cameraActivity.mCameraPreview.getPictureRotation());
        Bitmap bitmap = Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix, true);

        File rootDir = new File(cameraActivity.getFilesDir(), cameraActivity.mNote.getId().toString());
        rootDir.mkdir();
        File imageFolder = new File(rootDir, StringUtils.getImagePath());
        imageFolder.mkdir();

        long time = System.currentTimeMillis();
        File imageName = new File(imageFolder, StringUtils.getImageFilePath(String.valueOf(time)));
        FileOutputStream outStream;

        try
        {
            outStream = new FileOutputStream(imageName);
            //outStream.write(params[0]);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outStream);
            outStream.flush();
            outStream.close();
        }
        catch (IOException ioe)
        {
            ioe.printStackTrace();
        }

        return null;
    }
}

該方法適用於我測試過的所有設備，但是此解決方案還有另一個問題：需要較長時間，大約3000毫秒和50毫秒（保存相​​機返回的字節數組時）。 有沒有解決這個問題的辦法。 整個取向問題還是長期問題？

Answer 1

我也遇到過同樣的問題

 ExifInterface ei = new ExifInterface(photoPath);
 int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION,
                                 ExifInterface.ORIENTATION_UNDEFINED);

  Bitmap rotatedBitmap = null;
  switch(orientation) {

case ExifInterface.ORIENTATION_ROTATE_90:
    rotatedBitmap = rotateImage(bitmap, 90);
    break;

case ExifInterface.ORIENTATION_ROTATE_180:
    rotatedBitmap = rotateImage(bitmap, 180);
    break;

case ExifInterface.ORIENTATION_ROTATE_270:
    rotatedBitmap = rotateImage(bitmap, 270);
    break;

case ExifInterface.ORIENTATION_NORMAL:
default:
    rotatedBitmap = bitmap;
}

rotationImage方法：

public static Bitmap rotateImage(Bitmap source, float angle) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
return Bitmap.createBitmap(source, 0, 0, source.getWidth(), 
source.getHeight(),
                           matrix, true);
}

嘗試這種方法，我認為它可以幫助您