Table 1
Overview of common texture analysis approaches in MS.
  Assessment  Utility  Statistical approach   
 Firstorder  Global assessment of pixel distribution  Selfexplanatory yet lack of detail  Secondorder    Graylevel cooccurrence matrix (GLCM)  Joint probability of two pixels having cooccurring gray level values at a given distance and direction  Multiple properties of a texture (coarseness, correlation, contrast), less sensitive to larger scales  Run length matrix (RLM)  The number of times two or more pixels having the same value in a preset direction  Several properties of a texture (coarseness), less sensitive to larger scales 
 Spectral approach    Fourier transform  Entire frequency profile, using sinusoid basis functions  Useful for signals without temporal changes  Wavelet transform  Scalebased frequency content, using a deformable localizing “mother” wavelet as basis function  Multiscale analysis; less intuitive and can be computationexpensive  Stockwell transform  Scalebased frequency content, using fast Fourier transform and a flexible Gaussian localizing window  Fourierbased multiscale frequency content; computation time varies by image size and algorithm 

