PS Why is there translucent smoke in the constituency where he smoked with white strokes in The Road to Master Li Tao? Shouldn't the constituency be white

You first look at its selection, which uses the channel matting method. Channel matting means that the white part is deducted and the black part is not needed. In the next channel view, you can see that some gray parts are selected. The so-called gray is the translucent choice. What is a translucent choice? This means that some pixels are selected. For example, I have a picture, all red, but I use a rectangular selection box and cut it out with a little feather. The effect is that there is a gradient from red to white on the side.

In this picture, it is found that the channel is not bright in black and white, but has a gray part, so drawing a stroke with white will show a translucent area, that is, it will not show all white.

The larger the gray level in the channel (close to black), the fewer pixels are selected, and the less white it is.

The smaller the gray level in the channel (close to white), the larger the number of pixels selected, and the more white is displayed.

You got it? That's it ~