Research On Denoising Method Of Adaptive Fractional Medical Ultrasound Images Based On 2D-VMD

In the acquisition and transmission of ultrasound images,due to uneven acoustic impedance and high-frequency conversion,speckle noise in the image is easy to cause image quality deterioration,and it is difficult to identify and locate the lesion,which ultimately leads to increased difficulty in diagnosis and treatment of pathology.When dealing with speckle noise,the traditional denoising algorithm is incomplete and the denoising effect is not good,while the two-dimensional variational modal decomposition method can decompose the image signal.Therefore,this thesis combines the 2D-VMD decomposition method to analyze the fractional calculus theory.In-depth research is carried out,and a new denoising method is proposed by using the unique effect of the fractional integral operator on the signal.The specific research contents are as follows:The advantages and importance of medical ultrasound images and the problems encountered in the development process are introduced,and the two algorithms used are briefly introduced.Research status of fractional order theory in the field.The noise in the medical ultrasound image is analyzed,and its generation principle is deeply analyzed,and the types of noise are listed,and the most serious noise in the ultrasound image-speckle noise is studied in detail.This paper studies the ultrasonic image noise model,introduces the traditional image denoising algorithms,studies the methods and effects of traditional algorithms,and briefly introduces the advantages and disadvantages of these algorithms.According to the deficiencies,mainly analyzes the application characteristics and reasons of fractional integral theory in the field of image denoising,briefly describes the basic concepts of fractional integral theory,and lays the groundwork for the following work.Combining the fractional integral theory with the two-dimensional variational modal decomposition method,the decomposition principle and process of the 2D-VMD method are introduced.The ultrasonic image is decomposed into high frequency and low frequency parts according to frequency,and the high frequency image basically does not contain effective image information.After filtering out the high frequency image,the low frequency image is retained,and then the fractional integral operator model is established to construct the direction mask.,set the best fractional integral order for each retained ultrasonic low-frequency image,and process the image with this algorithm to achieve the best denoising effect.The algorithm has been tested enough.On this basis,a large number of experiments were carried out on the two groups of ultrasonic images respectively,and compared with other 9 methods.Two groups of real ultrasonic images were listed to enhance the intuitive contrast of noise.In order to facilitate future work,we add this algorithm to the medical image processing platform developed by Matlab GUI to enhance the noise reduction ability of the platform.According to the simulation experiments and analysis,the proposed 2D-VMD-based and improved fractional-order integral algorithm has obvious advantages in denoising ultrasonic images and maintaining the processing effect of image structure details.