Patent ID: 6967673

Claim:
An electronic endoscope system including a video scope having a solid-state image sensor that successively produces a frame of color image-pixel signals, and an image-signal processor that produces a color video signal based on said frame of color image-pixel signals, said electronic endoscope system comprising: a calculator that calculates a difference value between a value of a central single-color image-pixel signal and an average of values of some circumferential single-color image- pixel signals selected from single-color image-pixel signals surrounding said central single-color image-pixel signal; a color-balance alteration system that alters the value of said central single-color image-pixel signal based on the difference value calculated by said calculator; and a selector that selects said circumferential single-color image-pixel signals such that the distance between the circumferential single-color image-pixel signals to be selected and said central single-color image-pixel signal increases as a spatial frequency of an endoscope image to be reproduced based on said color video signal decreases.