clc;
clear;
close all;% 对灰度图进行灰度线性变换
img =imread('hua.jpg');
img =rgb2gray(img);%k大于1 增大图像的对比度,图像的像素值在变换后全部增大,整体效果被增强
k =1.25;
d =0;
gray1 = img * k + d;%k等于1 通过调整b ,实现对图像亮度的调整
k =1;
d =50;
gray2 = img * k + d;%k∈(0,1) 图像的对比度被削弱
k =0.5;
d =0;
gray3 = img * k + d;%k小于0 原来图像亮的区域变暗,原来图像暗的区域变亮 取反
k =-1;
d =255;
img_1 =im2double(img);
gray4 = img_1 * k +1.0;subplot(5,2,1),imshow(img),title('原图');subplot(5,2,2),imhist(img),title('原图直方图');subplot(5,2,3),imshow(gray1),title('k>0 d=0');%增大对比度
subplot(5,2,4),imhist(gray1),title('k>0 d=0直方图');subplot(5,2,5),imshow(gray2),title('k=1 d=50');%调节亮度
subplot(5,2,6