Question

使用相机API拍照时我会遇到照片方向问题，这种情况非常常见并且有一个共同的解决方案：

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;
    }
}

但此解决方案无法在所有设备中使用，且图片方向错误。为了解决这个问题，我删除了第二部分，并在拍照后将旋转校正移动到了：

    DECLARE
        a CONSTANT NUMBER := 3;
        b NUMBER NOT NULL := 5;
    BEGIN
        :X := :X + a + b + 3;
    END;
    .
    RUN
    PRINT :X

这适用于我测试的所有设备，但此解决方案还有另一个问题：需要很长时间，大约3000ms vs 50ms（保存摄像机返回的字节数组时）。有没有解决这个问题的方法。整个方向问题或长时间问题？

Answer 1

我遇到了同样的问题

 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;
}

rotateImage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);
}

尝试这种方法，我认为它可以帮助你

在相机应用程序中的相机图片方向

1 个答案: