Use of second-order statistics in texture synthesis-by-analysis

Synthesis-by-analysis is a well established paradigm for reproduction of textures having random appearance. In this contribution, in order to simplify the overall procedure in the case of colored textures, we exploit the second-order correlation existing between the texture chrominance and luminance components. Specifically, we perform the synthesis exclusively on the luminance component, while the chrominance components are reproduced by applying properly designed Wiener filters, whose coefficients have been previously calculated in the analysis stage. This approach yields excellent results especially on natural textures, which intrinsically present a high degree of correlation between the luminance and chrominance components. Moreover, to enhance the synthesis resolution, the same paradigm is then applied to reproduce high-order components of a texture multi-resolution representation based on the Circular Harmonic Functions expansion.