伽马变换曲线及伽马增强

x = linspace(0, 1);
y1 = x.^0.3; 
y2 = x.^0.5; 
y3 = x.^1; 
y4 = x.^2; 
y5 = x.^3.5; 
 
 
figure; 
hold on; 
xlabel('灰度输入值(相对值：R=I(i，j)/255)'); 
ylabel('灰度输出值(相对值)'); 
plot(x, y1, 'color',[124 187 50]/255); %0.3
set(0,'DefaultLineLineWidth',1.5);%设置线宽
hold on;
plot(x, y2, 'color',[0.00 0.45 0.74]); %0.5
set(0,'DefaultLineLineWidth',1.5);
hold on;
plot(x, y3,'color',[0.85 0.33 0.1]); %1
set(0,'DefaultLineLineWidth',1.5);
hold on;
plot(x, y4,'color',[255 174 0]/255); %2
set(0,'DefaultLineLineWidth',1.5);
hold on;
plot(x, y5,'color',[0.49 0.18 0.56]); %3.5
set(0,'DefaultLineLineWidth',1.5);
legend('γ = 0.3','γ = 0.5','γ = 1', 'γ = 2','γ = 3.5'); 

结果曲线图像：坐标框、坐标刻度值、字体可以在图像框中的  编辑→坐标轴属性  中设置

 伽马增强代码：

I = imread('F:\enhancement\images\SIRE_01.jpg');
I_gamma = im2double(I).^1.5;
figure; imshow(I_gamma);
imwrite(I_gamma, 'F:\load\gamma_1.5.jpg');

结果：gamma值在0-01之间是可以实现提升亮度的效果，等于1与原图像相同，大于1变暗