Method for de-noising medical ultrasonic image based on wavelet transformation and guide filter

The invention discloses a method for de-noising a medical ultrasonic image based on wavelet transformation and a guide filter, and the method comprises the following steps of: step 1) creating a medical ultrasonic image model; step 2) performing wavelet decomposition to the logarithm transformation image in the step 1) to obtain four frequency domains (LL1, LH1, HL1 and HH1); performing wavelet decomposition to LL1 in the low frequency domain so as to obtain four frequency domains (LL2, LH2, HL2 and HH2); repeating the step until to decompose the maximum layer J; step 3) performing filter processing to a wavelet coefficient in the final-layer low-frequency part (LLJ) by the guide filter; step 4) performing threshold valve method contraction treatment to the wavelet coefficient in each-layer high-frequency part (LHj, HLj and HHj, j=1, 2, ..., J); step 5) performing wavelet inverse transformation treatment to gain the de-noised medical ultrasonic image; performing exponential transformation to the medical ultrasonic image obtained in the step 5) to obtain de-noised ultrasonic envelope signals.