1. A medical diagnostic device comprising: photographing means for photographing a person to be examined to obtain an image of the person to be examined; image processing means for processing the image of the person to be examined obtained by the photographing means; image display means for displaying the image of the person to be examined processed by the image processing means; and control means for controlling the photographing means, the image processing means and the image display means, wherein the image processing means has: an image noise removal part which removes the noise in the generated image of a person to be examined; a signal component enhancement processing part which generates an enhanced-signal component image by performing signal component enhancement processing of the image from which the noise is removed by the image noise removal part; and an image combining part which generates a combined image by combining the image of the person to be examined, the image from which the noise is removed by the image noise removal part, and the enhanced-signal component image subjected to signal component enhancement processing by the signal component enhancement processing part.