Method for storing ultrasonic scan image and ultrasonic device

An ultrasonic device, comprising:

• means for computing a similarity of a frame of an image;
• means for determining whether the computed similarity of the frame is less than a threshold;
• and
• means for storing frames with similarities greater than or equal to the threshold previous to the frame when it is determined that the computed similarity of the frame is less than the threshold.

An ultrasonic device, comprising:

• an image acquiring unit configured to scan a target object to obtain an image;
• a buffer unit configured to store the obtained image;
• a processing unit configured to compute a similarity of a frame of the image;
• and
• a storage unit, wherein the processing unit stores frames with similarities greater than or equal to the threshold previous to the frame in the storage unit when it is determined that the computed similarity of the frame is less than a threshold.