img=uint8(zeros(151,151));
for x=1:151
    for y=1:151
        if (x-76)^2+(y-76)^2<1600
            img(x,y)=255;
        else
            ;
            
        end
    end
end
imwrite(img,'source_ring_150.bmp','bmp');

            
            
            
         