Abstract Astronomical images have complex morphological and hierarchical structures and irregular shaped textures, and they can be represented at different scales and directions. The purpose of this paper is to represent astronomical textures, and its mechanism is assumed from the perspective of orthogonality to extract the texture information. Based on orthogonality optimization criterion(OOC), wavelet filters, and anisotropic diffusion (AD), a method is presented to extract texture features for astronomical images. The theory assumes that the oscillation/texture component and the smooth piecewise/cartoon component are orthogonal to each other. The core technology is a parameter estimation method based on the orthogonality and AD. Firstly, the orthogonality measurement based wavelet thresholding scheme is adopted, and the multi-scale framework is used to extract and analyze the astronomical textures at different scales and directions. Then, the filtered smooth piecewise component is used to initialize AD. The parameter estimation is mainly applied to estimate the thresholds for multiscale wavelet filtering and AD iteration number. The images of galaxies and gravitational lensing are adopted for numerical experiments, and comparisons are implemented with 6 types of the currently used methods of image decomposition. The experimental results show that the proposed method can gain satisfying results in extracting astronomical textures, and it has advantages and advancement compared to other methods.
2015, Vol. 28 
