1. An endoscopic system, comprising: an endoscope provided with an objective lens at a tip of an insertion portion to be inserted into a body cavity; an image capturing sensor that captures an optical image input from the endoscope and condensed by the objective lens, and that outputs the captured image as an image signal; and processing circuitry configured to extract a low-frequency image with a frequency component lower than the image signal, extract a high-frequency image with a frequency component higher than the image signal, apply image quality enhancement processing to the low-frequency image, wherein the image quality enhancement processing includes processing of spatial-directional noise reduction, time directional noise reduction, color correction, and frequency band emphasis, and output at least the low-frequency image, whose image quality has been enhanced, as an output image, wherein the output image includes an image signal including pixel values obtained by adding pixel values of individual pixels of the high-frequency image to pixel values of individual pixels of the low frequency image, whose image quality has been enhanced, in accordance with condition information upon image capturing performed by the image capturing sensor.