The are a few problems with your code. First, if you want the image, you dont want to transpose. That will flip and rotate, As adam has pointed out, column and row, you arent actuall transposing anyway. A better and correct way to transpose is to use permute.
newImage = permute(imageData, [2 1 3]);
To actually flip, you should be able to use the flip function
newImage = flip(imageData,1);
newImage = flip(newImage,2);