Filtering method based on mathematical morphology and filtering system thereof

Abstract

The invention provides a filtering method based on mathematical morphology and a filtering system thereof. The filtering method comprises the steps that S1, a morphological filter is constructed based on the selected structural elements; and the shape of the structural elements is consistent with the waveform of signals to be processed, length of the structural elements is obtained according to signal frequency of the signals to be processed and the set sampling frequency through calculation, and the amplitude of the structural elements is determined based on the amplitude of the signals to be processed; S2, sampling is performed on the signals to be processed according to the set sampling frequency so that one-dimensional discrete signals are obtained; and S3, filtering processing is performed on the one-dimensional discrete signals by utilizing the morphological filter. The structural elements are not fixed and are obtained according to signal frequency of the signals to be processed and the set sampling frequency through calculation so that the structural elements are high in adaptability and suitable for engineering application. Furthermore, erosion operation involved in filtering processing is improved through combination of length of the selected structural elements and concretely improved into (fthetag)(n)=min[f(n+m-L-g(m)] so that intrinsic delay in a filtering algorithm can be eliminated and the filtering effect can be enhanced.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a filtering method and filtering system based on mathematical morphology. Background technique [0002] The mathematical morphological filtering method is a nonlinear time-domain filtering method. By selecting appropriate structural elements (mainly setting the length, shape, and amplitude of the structural elements), the morphological filter is constructed for filtering. It has the advantages of simple algorithm and easy programming. Realization, no phase offset and amplitude attenuation and other advantages. [0003] Because it is a nonlinear time-domain filter, mathematical morphology cannot obtain its frequency response characteristics through the traditional method of calculating the transfer function, so that in the process of selecting structural elements, most methods only conduct a large number of experiments on specific signals, and then summarize Summarize certain rul...

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Problems solved by technology

[0003] Because it is a nonlinear time-domain filter, mathematical morphology cannot obtain its frequency response characteristics through the traditional method of calculating the transfer function, resulting in the selection of structural elements, most of the methods are only a large number of experiments for specific signals, and then summarized Summarize certain rules and find relatively suitable structural elements, but when the signal frequency or sampling frequency changes, it is necessary to re-select the experiment, the adaptability is not strong, and it is not suitable for engineering applications

[0004] In addition, in the traditional mathematical morphology filtering algorithm, there is a defect of inherent delay in the erosion operation, and its inherent delay will increase with the increase of the length of the selected structural element, resulting in the selection of structural elements and the algorithm There are great limitations in the engineering application of

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