Achieving high resolution and long depth of field in ultrasonic B-mode images-a comparative study of restoration and multiple focusing techniques

The authors investigate the capability of an image restoration technique as an alternative to focusing, to improve resolution and the depth of field of images obtained by a nonfocused transducer. They study the restoration process from a system design point of view to replace the focusing system. A set of shift-invariant Wiener filters is used to restore the B-mode images. A Gaussian transducer has been employed because of its well-behaved point spread function in both near and far field, and the relative ease of restoration it provides. Simulation results indicate that the restoration technique is capable of improving the image resolution and the depth of field without blurring effects in the images of moving objects