Exif data TAG_ORIENTATION always 0

问题:

I need to know the orientation of an image from the gallery (taken by the camera). My initial approach was to use MediaStore.Images.Media.ORIENTATION which was working for my Droid 1. While testing on the HTC Thunderbolt that phone only saves 0 to that field.

I then moved to reading the exif data:

 ExifInterface exifReader = new ExifInterface(mFilePath);
 exifReader.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1);

This also returns 0 for every image. Anyone have ideas on how to properly get the orientation of a photo take on android?

回答1:

Here is the code I used onActivityResult() in my activity. The intent returned was for picking an image of the type image/*. Works well for me!

Uri imageUri = intent.getData();
String[] orientationColumn = {MediaStore.Images.Media.ORIENTATION};
Cursor cur = managedQuery(imageUri, orientationColumn, null, null, null);
int orientation = -1;
if (cur != null && cur.moveToFirst()) {
    orientation = cur.getInt(cur.getColumnIndex(orientationColumn[0]));
}  
Matrix matrix = new Matrix();
matrix.postRotate(orientation);

回答2:

My solution:

Remove any checking for orientation from exif data. I could not find one instance where it was accurate.

Use the standard String[] orientationColumn = {MediaStore.Images.Media.ORIENTATION}; to get an orientation.

If this is 0 use decodeStream...

if(o.outHeight > o.outWidth){
  //set orientation to portrait
}

else it is landscape

回答3:

This is a bug i found that was related to another android bug.. I found a reasonable solution posted here https://stackoverflow.com/a/8864367/137404