1. A method comprising: receiving a three-dimensional (3D) image sequence; receiving a subtitle file for the 3D image sequence, the subtitle file comprising a subtitle element and timing information associated with the subtitle element; associating the subtitle element with a segment of image frames of a temporal duration of the 3D image sequence, wherein associating the subtitle element with the segment of the 3D image sequence is based on the timing information; generating a right-eye abstract image from the segment and generating a left-eye abstract image from the segment, the right-eye abstract image representing multiple right-eye images of the segment, the left-eye abstract image representing multiple left-eye images of the segment; computing, by a computing device, an abstract depth map from the right-eye abstract image and the left-eye abstract image, the computing device comprising a processor capable of causing the computing device to compute the abstract depth map; computing, by the computing device, a proxy depth based on the abstract depth map for the subtitle element; using the proxy depth to determine a render attribute for the subtitle element; and outputting the render attribute.