Patent ID: 8274558

Claim:
An electronic endoscope system, comprising: an endoscope for obtaining an image corresponding to an image signal; a processor detachably attached to the endoscope for receiving the image signal of the image and processing the image signal, the processor including; an RGB transformer that transforms the image signal into an R signal, a G signal, and a B signal, an R amplitude of the R signal, a G amplitude of the G signal, and a B amplitude of the B signal each existing within a dynamic range; an R-signal amplifier that changes the R amplitude of the R signal in accordance with a predetermined gain value throughout the dynamic range, the R-signal amplifier including a plurality of R-signal amplifiers; and a GB-signal amplifier that nonlinearly changes the G amplitude of the G signal and the B amplitude of the B signal throughout the dynamic range in accordance with a nonlinear function, the GB-signal amplifier including a G-signal amplifier that includes a plurality of G-signal amplifiers and a B-signal amplifier that includes a plurality of B-signal amplifiers; a display connected to the processor for receiving a processed image signal from the processor and displaying a processed image corresponding to the processed image signal; a selector for selecting one of various observation targets to be observed, gains of the R-signal amplifier and the GB-signal amplifier being recorded as specific values for each of the various observation targets, the gains being selected according to the one of the various observation targets selected by the selector; and an output for outputting the R amplitude, the G amplitude, and the B amplitude from corresponding ones of the plurality of R-signal amplifiers, the plurality of G-signal amplifiers, and the plurality of B-signal amplifiers to the display in accordance with the one of the various observation targets selected by the selector, wherein each of the plurality of R-signal amplifiers changes the R amplitude of the R-signal in accordance with one of the various observation targets, each of the plurality of G-signal amplifiers changes the G amplitude of the G-signal in accordance with one of the various observation targets, each of the plurality of B-signal amplifiers changes the B amplitude of the B-signal in accordance with one of the various observation targets, and an R gain of the R signal equals a G gain of the G signal and a B gain of the B signal at limits of the dynamic range, with the G gain of the G signal and the B gain of the B signal increasing between the limits of the dynamic range.