1. A medical apparatus comprising: a first imaging device comprising a first image sensor having a first field of view; a second imaging device comprising a second image sensor having a second field of view smaller than the first field of view; and a processor configured to: process a first image acquired by the first image sensor so as to generate a first processed image having a first image magnification, process a second image acquired by the second image sensor so as to generate a second processed image having a second image magnification, adjust the first image magnification to be equal to the second image magnification so as to form an adjusted first image, and generate a stereoscopic image based on the adjusted first image and the processed second image.