Image Processing Reference
In-Depth Information
Fig. 1.2 The block diagram provides a general framework for many systems working with video
and images
Even though this topic is titled: “ Video and Image Processing ”italsocovers
basic methods from Image Manipulation and Image Analysis in order to provide
the reader with a solid foundation for understanding and working with images and
General Framework
No matter which category you are working within (except for Video and Image
Compression) you can very often apply the framework illustrated in Fig. 1.2 . Some-
times not all blocks are included in a particular system, but the framework neverthe-
less provides a relevant guideline.
Underneath each block in the figure we have illustrated a typical output. The
particular outputs are from a gesture-based human-computer-interface system that
counts the number of fingers a user is showing in front of the camera.
Below we briefly describe the purpose of the different blocks:
Image Acquisition In this block everything to do with the camera and setup of your
system is covered, e.g., camera type, camera settings, optics, and light sources.
Pre-processing This block does something to your image before the actual pro-
cessing commences, e.g., convert the image from color to gray-scale or crop the
most interesting part of the image (as seen in Fig. 1.2 ).
Segmentation This is where the information of interest is extracted from the im-
age or video data. Often this block is the “heart” of a system. In the example in
the figure the information is the fingers. The image below the segmentation block
shows that the fingers (together with some noise) have been segmented (indicated
by white objects).
Representation In this block the objects extracted in the segmentation block are
represented in a concise manner, e.g., using a few representative numbers as illus-
trated in the figure.
Classification Finally this block examines the information produced by the previ-
ous block and classifies each object as being an object of interest or not. In the
example in the figure this block determines that three finger objects are present
and hence output this.
It should be noted that the different blocks might not be as clear-cut defined
in reality as the figure suggests. One designer might place a particular method in
one block while another designer will place the same method in the previous or
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