The passage to the background is quite useful, when a picture is hair or a lot of holes in the time, 1.1 point of Eraser or Magic Eraser will have a very dead feeling it. Here is a record of the passage of the use of the process, to the edge of the back is better.
First Open Sister Liu
Here to pay attention to the mode is RGB and it is best to change the background to a layer.
Then click the Channel next to the bottom right column layer. Look at the contrast of three red, green and blue, which is based on the color of the picture. Here I choose Red, create a copy, only to make the red channel copy lit. Press Ctrl+l to tune the excellent order, adjust the input level inside the three small arrows, the contrast reached the maximum to select.
In this way, it's black-and-white. But the white ones will be eliminated when they are chosen. So here are a few ways to draw a circle of white black pens that we need to keep: otherwise this will be transparent because it will not be selected. If you need a wisp of air can be directly without painting black. Below is the black bottom Liu mm.
OK, dot Ctrl + Red copy on the left mouse button selected, pay attention to this generally selected is white, and we need is black, so, reverse select Ctrl+shift+i or menu selection inside Select the reverse, so that we need to select the Liu mm body.
Click on the layer and you'll see what we need. Direct CTRL + C CTRL + V copy paste, the layer copy out, the original dismiss off. This is what we need to memorize Liu mm.
Then to see if there is any place to modify again, not directly save or change the background slightly. Look to back Liu mm, wow so beautiful! Look at the lower left corner of the skirt, there is a bit empty oh, this is because look up all black there, I did not put this point all black, so it will be a little transparent.
