使用EXIF或光标始终0的图像取向

Question

我正在从我的肖像相机应用中拍照并发送到服务器。在发送时，我需要在必要时旋转图像。因此，我将图像保存在sdcard中并尝试获取我经历了与此相关的大多数帖子，但对我无效。

1. exifinterface

    File imageFile = new File(uri.toString());
   ExifInterface exif = new ExifInterface(imageFile.getAbsolutePath());
   int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,   ExifInterface.ORIENTATION_NORMAL);
   

   这里的方向始终是任何图像

的0

2. cusor

   int orientation = 0;
   final String[] projection = new String[] { MediaStore.Images.Media.ORIENTATION };
   final Cursor cursor = getApplicationContext()
                   .getContentResolver().query(uri, projection, null,
                           null, null); 
   if (cursor != null) {
   final int orientationColumnIndex = cursor.getColumnIndex(MediaStore.Images.Media.ORIENTATION);
   if (cursor.moveToFirst()) {
      orientation = cursor.isNull(orientationColumnIndex) ? 0 : cursor.getInt(orientationColumnIndex);
    }
   

   在这里，图像旋转也为零。如何找到图像的确切旋转？任何帮助将不胜感激。

Answer 1

请开始使用支持库中的exifinterface。它提供了一个支持输入流的构造函数。从URI获得路径是越野车。您需要此库：compile'com.android.support：exifterface:25.3.1'在您的build.gradle中。代码

private float getOrientation (InputStream image, Uri photoURI) {
    //ExifInterface myExif = new ExifInterface(photoURI.getPath());
    float photoRotation = 0;
    boolean hasRotation = true;
    try {
        ExifInterface exif = new ExifInterface(image);
        int exifRotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
                ExifInterface.ORIENTATION_UNDEFINED);
        switch (exifRotation) {
            case ExifInterface.ORIENTATION_UNDEFINED: {
                hasRotation = false;
            }
            case ExifInterface.ORIENTATION_ROTATE_90: {
                photoRotation = 90.0f;
                break;
            }
            case ExifInterface.ORIENTATION_ROTATE_180: {
                photoRotation = 180.0f;
                break;
            }
            case ExifInterface.ORIENTATION_ROTATE_270: {
                photoRotation = 270.0f;
                break;
            }
        }
    } catch (IOException e) {
            Log.d("ODDREAMS", e.getMessage());
    }
    if (!hasRotation) {
        try {
                String[] columns = {MediaStore.Images.Media.DATA, MediaStore.Images.Media.ORIENTATION};
                Cursor cursor = getActivity().getContentResolver().query(photoURI, columns, null, null, null);
                if (cursor == null) return 0;
                if (cursor.moveToFirst()) {
                    int orientationColumnIndex = cursor.getColumnIndex(columns[1]);
                    photoRotation = cursor.getInt(orientationColumnIndex);
                    Log.d("ODDREAMS", "CURSOR " + photoRotation);
                }
                cursor.close();
        }
        catch (Exception e) {}
    }
    return photoRotation;
}