| 摘要 |
PROBLEM TO BE SOLVED: To provide a means to improve image quality of ultrasonic images by effectively reducing speckle noise, or the like, contained in the ultrasonic images. SOLUTION: The first signal component of the first frequency band and the second signal component of the second frequency band are extracted from receiving signals, whereas envelop data are obtained from these signal components before the cross-correlation is calculated by a cross-correlation unit 40 with respect to these envelop data. The filter properties of a filter 42 in relation with the receiving signals is converted in accordance with the cross-correlation levels. |
