java - computer image representation method?

Question

Aren’t pixels generally in RGB space (0~255)

So how are the numbers in the above image transferred?

Answer 1

http://blog.csdn.net/cool1949...

For converting color to grayscale, there is a very famous psychological formula:

                      Gray = R*0.299 + G*0.587 + B*0.114
                      

There are other ways

Answer 2

After the image is converted into numbers, the number of numbers is equal to the width*height of the image. Each point of the image corresponds to a number. Converting a point into a number can be calculated by a special algorithm or formula, as mentioned above