matlab中imadjust（）函数做灰度图像的灰度变换

图像矩阵g有些为double类型，有些为uint8类型，揪心。
公式：g(x,y)=low_g + (high_g - low_g) / (high_f - low_f)*(f(x,y) - low_f)

clear
I=imread('C:\Users\lenovo\Desktop\1.jpg');
I=rgb2gray(I);%将彩色图像转换为灰度图像
imshow(I);
J=imadjust(I,[0.3;0.6],[0.1;0.9]);
figure;imshow(J);
low_f=0.3*255;high_f=0.6*255;low_g=0.1*255;high_g=0.9*255;
k=(high_g-low_g)/(high_f-low_f);
[M,N]=size(I);
for i=1:M
    for j=1:N
        if (I(i, j) <= low_f)                                        %灰度值小于low_f的像素点
            g(i,j) = low_g;                                         %结果为low_g
        elseif (low_f < I(i, j) && I(i, j) < high_f)        %灰度值在[low_f, high_f]
            g(i,j)=(low_g+k*(I(i,j)-low_f));
        else
            g(i,j) = high_g;                                       %灰度值大于high_f的像素点，结果为high_g
        end
    end
end
figure;imshow(g);