Real-Time Total Focusing Method for Ultrasonic Imaging of Multilayered Object

In imaging of multilayered object, total focusing method (TFM) combined with ray-tracing appeals to numerous researchers because of its superior image quality. But lots of iterative computation to calculate the incident points greatly increases its processing time. Based on line scan-conversion algorithm and Snell's principle, this paper proposes an efficient method to calculate the incident point. By dividing the image area into multiple regions, the time-consuming iterative calculation of point of incidence (POI) is eliminated. After introducing this method into TFM, the time complexity of Region-Division (RD) TFM is reduced by one order of magnitude. The simulation experiments validate that the imaging speed of RD-TFM is improved dozens of times compared to traditional TFM with ray-tracing. Besides, RD-TFM applies to multilayered objects with both planar and non-planar interface.