Stereo mosaicking and 3D-video for singleview HDTV aerial sequences using a low bit rate ROI coding framework

Low bit rate coding systems for the transmission of high quality aerial surveillance videos captured from UAVs are of high interest. One way to achieve high quality low bit rate video is to assume a planar surface of the earth, which is valid for sequences captured at high flight altitudes. Those systems only transmit the area of the current frame not contained in the previous frames (New Area) and reconstruct the already known areas by means of Global Motion Compensation (GMC) at decoder side. Although the bit rate can be reduced significantly compared to standardized video coders, no reconstruction of stereo video is possible at the decoder since each image pixel is transmitted only once and thus no motion parallax of objects can be observed in the reconstructed video. In this paper we present a coding system for stereo video reconstruction at very low bit rates. On-board the UAV we employ the camera path estimated from the image data to create a second view of a virtual camera. We derive convenient baseline distances and demonstrate the resulting perceptively good stereo impression for different test sequences. Similar to the coding concept introduced above we transmit a second New Area 2 in addition to the New Area already introduced. By doubling the bit rate to about 2 Mbit/s for a reasonable video quality of more than 38 dB, still saving more than 85% BD-rate compared to common HEVC coding, we are able to reconstruct a full HDTV (30 fps) stereo video at the decoder.