Abstract: A hybrid 2D transform, discrete Fourier transform-discrete wavelet transform (2D DFT-DWT), is applied to remove speckle noise mixed in the liver scatters so that liver scatters can be extracted. The proposed feature extraction algorithm uses DFT to filter the ultrasound image along the horizontal direction, and DWT along the vertical direction in order to extract the size feature of fatty liver scatters. The definitions and algorithms of partial DFT and partial DWT are given. Realistic processing of fatty liver ultrasound images are performed to show application of the proposed algorithm, and comparisons with classical 2D DFT and 2D DWT are made.

Key words: 2D hybrid transform, fatty liver scatters, ultrasonic image