Correspondence Texture Classification by Wavelet Packet Signatures

Abstract- This correspondence introduces a new approach to char-acterize textures at multiple scales. The performance of wavelet packet spaces are measured in terms of sensitivity and selectivity for the classi-fication of twenty-five natural textures. Both energy and entropy metrics were computed for each wavelet packet and incorporated into distinct scale space representations, where each wavelet packet (channel) reflected a specific scale and orientation sensitivity. Wavelet packet representations for twenty-five natural textures were classified without error by a simple two-layer network classifier. An analyzing function of large regularity ( 0 2 0) was shown to be slightly more efficient in representation and discrimination than a similar function with fewer vanishing moments (Ds). In addition, energy representations computed from the standard wavelet decomposition alone (17 features) provided classification without error for the twenty-five textures included in our study. The reliability exhibited by texture signatures based on wavelet packets analysis suggest that the multiresolution properties of such transforms are beneficial for accomplishing segmentation, classification and subtle discrimination of texture. Index Terms- Feature extraction, texture analysis, texture classifica-tion, wavelet transform, wavelet packet, neural networks. I