The present disclosure provides an image processing method in a diagnostic apparatus of diagnosing a disease using a captured image of an affected area, comprising: separating the stored captured image into a brightness component and a color information component； separating the brightness component into a base component and a detail component； highlighting the base component and/or the detail component； restoring a brightness component from a highlighted base component and the detail component, and/or from the base component and a highlighted detail component； and generating a highlighted image using the restored brightness component and the color information component.
