Information Technology Reference
In-Depth Information
Fig. 5.15 Vibrational mode of the Belousov-Zhabotinsky medium under conditions of high
illumination
optical input of the image. When the exposure of the image exceeds a certain value
that depends on the composition of the medium and the intensity of radiation, the
medium begins to operate in a mode similar to that of the guiding center. When a
black-and-white image is entered, contours appear on the borders of its fragments
that propagate along the illuminated areas of the image (Fig.
5.15
). The contours
appear sequentially at intervals of 20-40 s and cannot be suppressed by light
radiation. A remarkable feature of this process is that if the flashing exposure
(image input) is arrested at some, the medium immediately begins to operate in a
vibrational mode (Fig.
5.16
). In this case all the appearing contours are involved in
the oscillations. When the illumination is turned on again the medium begins to
function in the guiding center mode.
Qualitatively, the process of optical information input can be described as
moving the point of intersection of zero isoclines (Fig.
5.2
) as the isocline inhibitor
shifts under the influence of light radiation. At a certain magnitude of illumination
this point undergoes transition from the vibrational to the excitable mode and,
apparently, becomes a guiding center.
This feature of the environment functioning in the vibrational mode plays an
important role in image processing. The number of emerging contours is not
connected to the structure of the image and is solely determined by the specific
features of the dynamics of the medium—the composition and the exposure of the
image. Therefore, when the medium performs image processing operations in the
vibrational mode, the maximum exposure value must first be determined while the
medium still remains in the vibrational mode.
Let us return to image processing by Belousov-Zhabotinsky media in the
oscillatory mode. They can perform virtually any operations of black-and-white
image processing. But the most interesting possibilities arise in the case of halftone
images. As already evident from the examples shown before, a unique property of
the Belousov-Zhabotinsky media is that they convert the spatial distribution of
