Biomedical Engineering Reference
In-Depth Information
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(a)
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FIGURE 16.19
(See color insert)
(a-b) Red-green-
blue representations of the spectral
images. (c) Measured action spectra
of wild-type (wt), 4-keto (4k), and
3,4-didehydro (de) bacteriorhodopsin,
and (d-e) responses of the theoretical
color-sensitive imaging array to the
input images.
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(e)
them are well suited for processing of visual information. Among these molecules, BR is
one of the most studied one.
The objective of this chapter was to discuss the nature of color and the design factors for
the application of BR to imaging. Since color plays an important role in visual perception,
it should be properly considered in every design of color-sensitive or color-reproduction
systems in which human beings have some part. The practical goal of our research has
been to develop photosensors and imaging devices based on BR as a case study of a mate-
rial proposed even to molecular electronics and nanoscale applications. The experiments
with the imaging arrays based on different types of BR showed reliable photoelectric
responsivity and usability of the arrays to color-sensitive and even video applications.
Based on the results, it is apparent that these biomolecules have characteristics distinct
from the current technologies for imaging and visual information processing: no filters are
needed to achieve color sensitivity, thin films and coatings offer numerous possibilities for
novel array geometries, and optically active molecules enable preprocessing of visual data.
