Xcell Journal Issue 78: Charge to Market with Xilinx 7 Series ...

XPERT OPINION
Figure 3 – Pedestrian detection and tracking capabilities included a “trip wire” alarm that
reported when an individual moved within a bordered portion of the video frame.
of the video-analytics IP cores, with
the generated metadata passing to a
secondary algorithm suite for additional
processing. Challenges this time
around included:
• Resolving the fundamental tradeoff
between unwanted noise and
proper object segmentation
Input
Video
VA IP
Config.
File
Appl.
Config.
File
VA IP
Configuration
Preprocessing
• Varying object morphology (form
and structure)
• Varying object motion, both person-to-person
and over time with
a particular person
• Vanishing metadata, when a person
stops moving, for example,
is blocked by an intermediary
Parser Tracker Identifier
Get one
frame of
metadata,
parse and
preclassify
Specialized Video Analytics Hardware
Image
Analysis
Match metadata
objects to
tracked objects
Object
Segmentation
Predict motion
of each
tracked object
Tracked
objects list
Metadata
Generation
Once per frame
Identify tracked
objects by
category
object or blends into the background
pattern
• Other objects in the scene, both
stationary and in motion
• Varying distance between each
person and the camera, and
• Individuals vs. groups, and dominant
vs. contrasting motion vectors
within a group
With respect to the “trip wire”
implementation, four distinct video
streams were particularly effective in
debugging and optimizing the videoanalytics
algorithms:
• “Near” pedestrians walking and
reversing directions
• “Near” pedestrians walking in
two different directions
• A “far” pedestrian with a moving
truck that appeared, through a
trick of perspective, to be of a
comparable size, and
• “Far” pedestrians with an
approaching truck that appeared
larger than they were
On-Screen
Display
Figure 4 – The final phase of the project migrated from Xilinx’s simulation models to actual FPGA IP blocks. BDTI also ported the second-level algorithms
from an x86 CPU to an ARM-based SoC, thereby paving the path for the single-chip Zynq Extensible Processing Platform successor.
18 Xcell Journal First Quarter 2012
Test
for
alarm
Output
Video
Process
for
OSD