statxtre.rar_regional descriptor_statxtre_亮度_图像纹理_纹理

function [t] = statxtre(f,scale) % STATXTURE Computes satatistical measures of texture in an image. % T = STATXURE(F,SCALE) computes six measures of texture from an image (region) F. % Parameter SCALE is a 6-dim row vecor whose elements multiply the 6 corresponding elements of T for scaling purposes. % If SCALE is not provided it defaults to all 1s. The output T is 6-by-1 vector with the following elements: % T(1) = Average gray level % T(2) = Average contrast % T(3) = Measure of smoothness % T(4) = Third moment % T(5) = Measure of uniformity % T(6) = Entropy if nargin == 1 scale(1:6) = 1; else % Make sure it's a row vector. scale = scale(:)'; end % Obtain historgram and normalize it. p = imhist(f); p = p./numel(f); L = length(p); % Compute the three moments. We need the unnormalized ones % from function statmoments. These are in vector mu. [v,mu] = statmoments(p,3); % Compute the six texture measures; % Average gray level. t(1) = mu(1); % Standard deviation. t(2) = mu(2).^0.5; % Smoothness % First normalize the variance to [0 1] by % dividing it by (L-1)^2 varn = mu(2)/(L-1)^2; t(3) = 1-1/(1+varn); % Third moment (normalized by (L-1)^2 also). t(4) = mu(3)/(L-1)^2; % Uniformity. t(5) = sum(p.^2); % Entropy. t(6) = -sum(p.*(log2(p+eps))); % Scale the values. t=t.*scale;