1. An automated method for detecting corrosion or crack defects, comprising: obtaining a first of a plurality of ultrasound images acquired with guided Lamb waves; processing the first image using a synthetic aperture focusing technique (SAFT) to enhance a resolution and a signal to noise ratio of a first extracted ultrasonic image; applying a systemic background noise suppression algorithm to the first extracted ultrasonic image to render a second extracted ultrasonic image having reduced noise; and applying a deconvolution linear filtering process to the second extracted ultrasonic image to render a third extracted ultrasonic image.