function F_con=txsim_con(f)
% TXSIM_COM  Texture contrast measure
%	F_crs=txsim_con(f) computes the contrast measure suggested by
%	H. Tamura, S. Mori, T. Yamawaki, ``Textural Features Corresponding
%	to Visual Perception'', IEEE Trans. Sys., Man, Cyb., June 1978

F_con=mean(mean((f-mean(f(:))).^4))/std(f(:))^4;

