Image enhancement algorithm of Dongba manuscripts based on wavelet analysis and grey relational theory

Image enhancement is an important part of the image processing of Dongba manuscripts. For the low-contrast and fuzzy Dongba manuscripts image, in this paper, an image enhancement algorithm based on wavelet analysis and grey relational analysis is proposed. Firstly, the wavelet transform is used to decompose the Dongba manuscripts image into three levels, and the corresponding low-frequency components and high-frequency components are obtained. Then, the interference signal and the useful signal in the high frequency component are distinguished by the grey relation analysis theory. Finally, inverse wavelet transformation is used to reconstruct the image so that the contrast enhancement and background suppression can be achieved. The experimental results show that compared with the conventional filtering method and wavelet threshold denoising enhancement method, the proposed method has the highest peak signal-to-noise ratio, suppresses the noise while enhancing the image details and improving the image contrast.