Digital Signal Processing Reference
In-Depth Information
Introduction to Content-BasedVisual Processing
7
Figure 1.2.
Convergence of Technologies for Content-Based Video Processing: Image
Segmentation and Motion Estimation provide numerous means of extract and orga-
nizing explicit visual information; Computer Vision, Neural Networks and Adaptive
Signal Processing provide the computational and algorithmic framework that fits the
visual information to coherent representation of video objects.
IMAGE SEGMENTATION
Image segmentation can be considered a special case of our video
object extraction upon a single frame (see Figure 1.3). The image seg-
mentation techniques provide many methods of feature extraction and
integration of contextual information that form the starting point for
most of work in our topic. Image segmentation must extract, categorize,
arrange and connect visual features with contextual information to find
a coherent segmentation. We leverage these technologies and techniques
into our video object extraction and representation systems and extend
them to handle multiple frames.
Image segmentation covers both the use of spatial correlation and
propagating high-level information into segmentation. Image segmenta-
tion provides us with many useful low-level feature extraction tools: the
concept of locality, spatial correlation and edge detection. Topics such
as color and texture identification are also relevant to this topic.
Image segmentation must derive its understanding from only a single
frame of information; therefore, representations of
a priori
video ob-
ject knowledge must provide much of the segmentation information. Al-
though we avoid the high-level understanding algorithms that are limited
by their specificity, in our system design, we use many image segmen-
tation algorithms that use global information without loss of generality
such as edge joining algorithms, region growing, hierarchical representa-
tion and clustering algorithms. In video processing, we have the benefit
of working with multiple frames and can make use of both spatial and
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