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| Equalization of Superficial Ultrasonic Images |
| School of Medical Instrument and Food，University of Shanghai for Science & Technology，Shanghai 200093,China |
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Abstract Equalization algorithm can effectively reduce the correlation between ultrasonic image samples; improve the performance of despeckling methods. But acquiring equalization filter parameters based on in vivo images requires a large amount of calculation which is not conducive to realtime processing. Aiming at superficial ultrasonic images, this paper gives an effective equalization method that avoids lots of realtime calculation. Based on the ultrasonic RF imaging formation model, this paper analyzed the spectrum of ultrasonic phantom echo signals, filtered the spectral component of the tissue reflectivity function, obtained the pointspread function and constructed the equalization filter to analyze its effect for superficial images. With the parameters acquired from the phantom the equalization filter used for superficial ultrasonic images can reduce the correlation. Compared with direct despeckling methods, the speckle SNR of preprocessed de-speckling methods has been improved about 19.2%, the performance of de-speckling methods gets improved. For superficial ultrasonic images, parameters of equalization filter can be acquired through ultrasound phantom in advance，it can reduce the calculation of despeckling process and easy to realize realtime processing.
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