%裝載并圖示原始圖像
load gatlin2;
subplot(2,2,1);
image(X);
colormap(map);
title('原始圖像');
axis square;
%==============================
%生成含噪圖像并圖示
init=2055615866;
randn('seed',init);
X1=X+10*randn(size(X));
subplot(2,2,2);
image(X1);
colormap(map);
title('含噪圖像');
axis square;
%=======================================
%消噪處理：設置函數wpdencmp的消噪參數
thr=10;sorh='s';
crit='shannon';
keepapp=0;
X2=wpdencmp(X1,sorh,3,'sym4',crit,thr,keepapp);
%==============================
%畫出消噪后的圖像
subplot(2,2,3);
image(X2);
colormap(map);
title('全局閾值消噪圖像');
axis square;
%對圖像進行平滑處理以增強消噪效果，這里采用中值濾波的方法
for i=2:175;
    for j=2:259
        Xtemp=0;
        for m=1:3
            for n=1:3
                Xtemp=Xtemp+X2(i+m.2,j+n.2);
            end
        end
        Xtemp=Xtemp/9;
        X3(i,j)=Xtemp;
    end
end
%==============================
%圖示平滑結果
subplot(2,2,4);
image(X3);
colormap(map);
title('平滑后的圖像');
axis square;