Gray and gray values are generally equal, right?

The so-called gray scale refers to the level of color from all white to all black. According to different precision, the gray level is different, such as 8, 16, 32, etc. The most commonly used level is 256. When we determine the gray scale, such as 256, then its gray scale value is from 0 to 255, that is, each gray scale value corresponds to a specific color, of course, it is only a mixed color of black and white. Generally speaking, the gray value is set to the n power of 2, but the smallest value is also 8. As for the number of n, it depends on the requirements of precision Chengdu. Early black-and-white TVs used gray. At present, the gray scale in photography generally uses 18 color card to determine the total white in the photographic environment to adjust the white balance; But also in image processing.