Graphics Reference
In-Depth Information
been left behind a parked car or it can show how close the vehicle is getting to other
vehicles when trying to park in a tight spot. In fully automated systems, the vehicle
is able to use this information to actually park itself. The surround view system
cameras typically have 190
◦
field of view and stream video to the central processor
either as analog NTSC, digital uncompressed via LowVoltage Differential Signaling
(LVDS/FPD-Link), or compressed (MJPEG or H.264 format) via Ethernet (using
Ethernet AVB protocol [
8
]). The camera streams can then be stitched together to
form a cohesive and seamless view around the outside of the car. Outputs from the
surround vision systemare sent to a console at VGAor higher resolution. This display
makes it easy for the driver to recognize and react to any hazards surrounding the
car. Additionally, 3D graphic rendering could be used for highly realistic surround
views. A high-level block diagram LVDS/FPD-Link-based surround view system is
shown in Fig.
3.4
.
In this example, four satellite cameras are sending video over LVDS link to the
central processor. The surround view central processor is synchronizing the satellite
cameras via back channel LVDS communication. Simplified data flow for surround
view central processor is shown in right panel of Fig.
3.4
. Prior to frame photometric
matching and stitching, video captured from the satellite cameras is corrected for
lens distortion. Optionally, the system can use incoming video to check for objects
around the vehicle and to give cross traffic alerts to the driver.
By connecting the camera system directly to the central processor via LVDS link
(or though analog connection), the video streams cannot be exploited by other sys-
tems in the vehicle. To address this challenge, it is possible to use an in-vehicle
Ethernet-based network architecture. In this case, each system connected to the net-
work is capable of receiving data from any camera distributing compressed and
packetized bit stream across the network.
Fig. 3.4
Left panel
Block diagram of LVDS-based surround view system;
Right panel
Simplified
data flow in LVDS-based surround view system. Optional processing steps are presented in
light
shade of gray
