Matlab obtains the RGB value and gray value of a certain point of the image

1. Show that picture first

1. img_a = imread('test.tiff'); %写文件名字，文件放在matlab可检索的目录下

2.  

3. imshow(img_a);

                                                                 

 

2. Click on the logo symbol in the upper left corner

                                     

 

3. Click on the target image to display the RGB value of the point. If the three are equal, the point is gray.