Let me start by saying that I found this bug while running CM10 on my GS3 but it looks like it might be the same in the stock rom as well. Please read so we can fix this issue.
I found a bug with the portrait picture messages being rotated incorrectly in an MMS. I searched on here and have found more reports of the bug no have not found a fix. I have been trying to figure it out and think I found the reason for the issue but do not have the knowledge or skill to fix. Portrait pictures taken by the GS3 have their height and width incorrectly labeled in the details of the photo. I just tested this on my GS3 running CM10 and my wife's stock GS3. We both took full resolution pictures in portrait more and then went into the details of the photo. On both phones the photo was shown to have a 3254 W x 2448 H and an orientation of 90. If I take a picture in landscape mode it shows 3264 W x 2448 H and an orientation of 0. When I look at a portrait picture taken by a different camera (non phone) the details read 3000 W x 4000 H and an orientation of 0.
The strange thing is that the picture message app on the stock phone does not have the rotation issue. To test further I took the picture from before that did rotate incorrectly and I edited the picture with the stock Android editing app. All I did was apply a filter and saved the picture. The new details of the picture read: 960 W x 1280 H and an orientation of 0. When I put that picture into an MMS it knows exactly what to do with it and rotates properly.
I tested this in every resolution that the camera app will take and it always shows portrait pictures with a Width that is greater than Height and a Orientation of 90.
One other thing that I tested was sending a portrait screenshot. When taking a screenshot with built in Android method it actually doesn't show a Width and Height at all but shows the orientation as 0. These screenshots rotate and send properly in an MMS.
Hopefully my testing helps somebody develop a fix for this issue. If I figure anything else out about this I will continue to post. Is there anywhere else I should post this to help document the bug?
I am on the 10-07-2012 nightly but this bug seems to date back into August based on the posts in this thread.