localhisteq3.m

这是直方图均衡化（改进后）的MATLAB程序

function g=localhisteq3(f,m,n)
if nargin==1
    m=3;n=3;
elseif nargin==2
    n=m;
end
if(~(round(m/2)~=m/2) | ~round(n/2)~=n/2)
    error(' is odd')
end
classin=class(f);
f=im2unit8(f);
den=m*n;
v=0:255;
[R,C]=size(f);
f=padarray(f,[m,n],'symmetric','both');
xg=(m+1)/2+1;
yg=(n+1)/2+1;
subimage=f(x0-1 : x0+m-2,y0-1 : y0+n-2);
histim=hist(double(subimage(:)),v);
xg=0;
for x=x0:R+(m+1)/2
    histabove=hist(double(f(x-1,y0-1 : yo+n-2)),v)/den;
    histblow=hist(double(f(x-+m-1,y0-1 : yo+n-2)),v)/den;
    histim=histim-histabove+histblow;
    histimhoriz=histim;
    xg=xg+1;
    yg=0;
    for y=y0 : C+(n+1)/2
        yg=yg+1;
        histleft=hist(double(f(x : x+m-1,y-1)),v)/den;
        histright=hist(double(f(x : x+m-1,y+n-1)),v)/den;
        histimhoriz=histim-histleft+histright;
        cdf=cumsum(histimhoriz);
        value=f(x+(m+1)/2-1,y+(n+1)/2-1);
        g(xg,yg)=cdf(double(value+1));
    end
end
g=changeclass(classin,g);