1. A method of processing an image in a diagnostic apparatus for diagnosing a cutaneous lesion using a cutaneous image, the method comprising: (a) obtaining a first detail image by performing a first component separation filter processing on a brightness component of the cutaneous image; (b) obtaining a second detail image by performing a second component separation filter processing on the brightness component of the cutaneous image, the second component separation filter processing having properties different from those of the first component separation filter processing; (c) generating a third detail image based on the first detail image and the second detail image; (d) newly generating a third base image based on the third detail image; and (e) combining the third detail image with the third base image to restore a brightness component and generate a highlighted image; wherein the first component separation filter processing is a first edge preserving smoothing filter processing configured to highlight a periphery of an edge of the cutaneous image, and wherein the second component separation filter processing is a second edge preserving smoothing filter processing configured to attenuate a periphery of an edge of the cutaneous image.