Digital Signal Processing Reference
In-Depth Information
Figure 4.19.
Analysis of each of the MPEG-4 test sequences
although it splits the motorboat and its wake into two video objects.
The large coastguard boat is partially occluded within the sequence by
the frame edge, but when the large coastguard boat is more than halfway
onto the screen, our system can tolerate some measure of occlusion. Ob-
jective results for the coastguard sequence (defined in Section 4.23) are
shown in Figure 4.24.
RESULTS FROM CONTAINER SEQUENCE
The container sequence (frames 0-45, downsampled by 5) has two
moving objects of interest: the large container ship and the small boat
behind.it. Since the objects are so far away from the camera, the pro-
jected motion of the objects between frames is beyond the pixel reso-
lution and too small to be extracted by the motion analysis. Thus, for
this sequence, we must downsample the frames by five. However, this
manual preprocessing can be replaced by an automatic process based
upon a simple activity measure.
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