Page 174 - Algorithm Collections for Digital Signal Processing Applications using MATLAB

4. Selected Applications 163

res5=reshape(res,1,size(res,1)*size(res,2));
res=blkproc(y,[32 32],[8 8],'skew(x)');
res6=reshape(res,1,size(res,1)*size(res,2));
res=blkproc(y,[32 32],[8 8],'kurt(x)');
res7=reshape(res,1,size(res,1)*size(res,2));
res=[res1 res2 res3 res4 res5 res6 res7 ];
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huevar.m

function [res]=huevar(x)
x=hist(reshape(x,1,size(x,1)*size(x,2),500);
res=var(x);
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unif.m

function [res]=unif(x)
z=reshape(x,1,size(x,1)*size(x,2));
h=hist(double(z),256);
h=h/sum(h);
res=sum(h.^2);

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entropy.m

function [res]=entropy(x)
z=reshape(x,1,size(x,1)*size(x,2));
h=hist(double(z),256);
h=h/sum(h);
res=(-1)*sum(h.*log2 (h+eps));

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relativesmooth.m

function [res]=relativesmooth(x)
z=reshape(x,1,size(x,1)*size(x,2));
res=1-(1/(1+var(z)));

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