The resolution of narrow band imaging is improved, while color reproducibility is improved when performing white-light observation. Provided is an endoscope system including an image pickup device having three types of color filters, said types being blue, green, and magenta, and also including an image processor that generates an image by processing a signal acquired by the image pickup device. The image processor includes a ratio calculator that calculates the ratio between a blue signal and a magenta signal, and also includes a red-signal generator that generates a red signal based on the ratio calculated by the ratio calculator.