Patent ID: 6879339

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 composed of at least two frames of different monochromatic image-pixel-signals, which comprises a color-balance alteration system including: an extraction system that successively extracts a set of monochromatic image-pixel-signals from a frame of monochromatic image-pixel-signals, the set of monochromatic image-pixel-signals being composed of a central monochromatic image-pixel-signal, and neighbouring monochromatic image-pixel-signals surrounding said central monochromatic image-pixel-signal; a selection system that selects all sets of three monochromatic image-pixel-signals from said set of monochromatic image-pixel-signals, each set of three monochromatic image-pixel-signals being composed of said central monochromatic image-pixel-signal, and two neighbouring monochromatic image-pixel-signals aligned with each other such that said central monochromatic image-pixel-signal lies therebetween; a determination system that determines whether a signal level of said central monochromatic image-pixel-signal is smaller than signal levels of said two neighbouring monochromatic image-pixel-signals with respect to all said sets of three monochromatic image-pixel-signals; and a decrease system that decreases the signal level of said central monochromatic image-pixel-signal when it is determined by said determination system that the signal level of said central monochromatic image-pixel-signal is smaller than both the signal levels of said two neighbouring monochromatic image-pixel-signals in at least one of the sets of three monochromatic image-pixel-signals.