1. A medical diagnostic device comprising: a photographing unit having a transmission sensor and a reception sensor, and photographing a person to be examined to obtain an image of the person to be examined by transmitting an electromagnetic wave or an X-ray or an ultrasound from the transmission sensor and detecting the electromagnetic wave or the X-ray or an ultrasound transmitted through the person to be examined with the reception sensor; an image processing unit having an image data storage, and processing the image of the person to be examined obtained by the photographing unit; an image display unit having a screen and displaying the image of the person to be examined processed by the image processing unit on the screen; and wherein the image processing unit includes: a noise removal part which removes a noise in the obtained image of a person to be examined; and a signal component enhancing part which generates an enhanced-signal component image by performing signal component enhancement processing of the obtained image in which noise was removed by the noise removal part, which includes a sharpening process by generating a dilated image and an eroded image by using a morphological filter, calculating weight indexes indicating the degree of dilation for the dilated image and weight indexes indicating the degree of erosion of the eroded image, and performing weighted addition of the dilated image and the eroded image by using the calculated weights and in response to the weighted addition, the generated enhanced-signal component image will comprise three regions: a first region where the brightness value will be the brightness value of the dilated image, a second region where the brightness value will be the brightness value of the eroded image and a third region where the brightness value will be the brightness value resultant of the weighted addition of the indexes of the dilated image and the eroded image.