An electronic endoscope system has an image sensor driver configured to read one line's worth of image-pixel signals in order； at least four line memories configured to store one line's worth of image-pixel signals, respectively； and an interpolation processor that interpolates image-pixel signals of interpolated scanning lines to generate an enlarged image. The interpolation processor generates one line's worth of interpolated image-pixel signals based on image-pixel signals that are stored in the line memories. The image sensor driver reading one line's worth of image-pixel signals intermittently, and the interpolation processor suspends a writing of image-pixel signals that are stored in the line memories in accordance to a suspension of the outputting of the one line's worth of image-pixel signals from the image sensor.
