Real-time 3D ultrasound imaging

Usually, 3D images are contaminated by a noise that can be modeled as an impulsive, Gaussian, or may be speckle one. In this paper we present the implementation of the three dimensional (3D) filters applied to ultrasound (US) imaging. Such a filtering technique uses different modified order statistics algorithms suppressing noise and preserving the small-size image details. The performance of the presented filters has demonstrated for 3D objects by means of use the objective criteria PSNR and MAE, and subjective one analyzing an error image. The PSNR and MAE criteria for Gaussian noise contamination have showed that Alfa Trimmed Mean and ROM filters presented the better results, and the MM-KNN filter obtained good results for small values of contamination. MMKNN filter was the most efficient in impulsive noise suppression for higher level of contamination, also reducing the speckle noise that is natural for coherent US transducer. The DSP TMS320C6711 was employed for implementation in 3D imaging. The processing times for Alfa Trimmed Mean filter present sufficiently high values. Filters: selection of median and of mean show significantly small times, but for LUM type filters the time values are increasing during the ordering of the voxels. The time values for RM-KNN filters are larger in comparison with other filters, but their performance is sufficiently better, and by selecting an adequate configuration of the voxels the time values can be reduced significantly without losing of good filter quality.