An image obtaining method and apparatus for an endoscope apparatus wherein
reductions to the gradations of the image data borne by the analog signal
are suppressed and digital values having a narrower dynamic range are
obtained when the photoelectrically converted and outputted analog signal
is converted to digital values. A living tissue is irradiated by an
illuminating light and an excitation light, which are each emitted at
different timings; whereupon a fluorescent image formed of the fluorescent
light emitted from the living tissue and a standard image formed of the
reflected light reflected from the living tissue are received, converted
to respective analog signals, and outputted by the same photoelectric
converting element. In converting these analog signals to digital values,
the analog signal representing the fluorescent image is amplified by a
larger gain than that representing the standard image.
