An imaging system for use with an endoscope, including a light source which
emits white light and excitation light which will produce a fluorescence
response by an object under inspection, an imaging camera including
separate paths for processing images produced by white light and
excitation light, a selection device that causes the imaging device to
operate in a white light mode or an excitation light mode, and a
protective device that prevents damage to high-sensitivity imaging
components from exposure to excessive light input. Fluorescent image data
are separated into at least red and green color bands which are separately
processed to produced a video display in which normal tissue is displayed
in predetermined specific color, and abnormal tissue in one or more
distinctly different colors. In one embodiment, an image color
interpretation guide is provided in the form of multiple color bars which
are superimposed on a single video display device with the image display.
of different kinds. In another embodiment, color control is provided by
adjusting the amplification of the imaging components for each of the
color bands while viewing tissue known to be normal using a recursive
algorithm until the ratio of the maximum values of the color separation
signals fall within a predetermined range. The high-sensitivity imaging
components are protected by controlling impingement of light on the
imagining components, selectively controlling emission of white and
excitation light from the light source, and controlling the power source
for the imaging components.