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

Abstract

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.

Description

technical field [0001] The invention is applied in the field of medical image denoising. Background technique [0002] In the field of medical imaging, imaging technologies such as ultrasound imaging, CT, and MRI have been applied in medical clinical diagnosis. Ultrasound imaging is safer than other imaging techniques because it is non-invasive, non-radioactive, fast and convenient. Especially in clinical applications such as observing fetal growth in pregnant women and diagnosing abdominal organ lesions, the use of ultrasound imaging technology is even more important. [0003] According to the statistics of breast cancer in women given by the American Cancer Society in 2013, in the past year, there were 232,340 new cases of invasive breast cancer and 39,620 deaths from breast cancer in American women. The main technology for detecting human breasts and other organs of the abdomen is ultrasonic imaging technology, which is commonly referred to as B-ultrasound images. Ther...

AI Technical Summary

Problems solved by technology

The common ones are mean filtering and median filtering, etc., but when there is obvious edge information in the image, the usual neighborhood operation will change the gray value of the edge points of the image, thus making the edge of the image blurred

Therefore, the bilateral filter that can keep the edge information well has been recognized by everyone, but due to the high computational complexity of the bilateral filter and the phenomenon of "gradient reversal", it cannot meet the real-time requirements of the medical ultrasound imaging system.

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