Every time you work in Adobe Photoshop and select an area, you create an alpha channel. The toolkit of the program includes many options for manipulating alpha channels, but one of the most important is that they can be saved and used later.
Necessary
Russified version of Adobe Photoshop CS5
Instructions
Step 1
Open any image: click the "File" menu item, then "Open" (this action can be performed faster by pressing the key combination Ctrl + O), select the file and click the "Open" button. Select the area in the picture using the Rectangular Marquee (hotkey M, switch between adjacent elements Shift + M) or Lasso (L, switch - Shift + L). In our case, it doesn't matter which area, so select any. The alpha channel has been created.
Step 2
There are two ways to save the selection. First: find the "Layers" window (if it is not there, call it with the F7 hotkey), find the "Channels" tab on it and click the "Save selected area in a new channel" button, which is located in the lower right corner of the window. Second: Click the menu item "Selection"> "Save Selection"> "OK". Optionally, you can give a name to the new alpha channel.
Step 3
Saved alpha channels, they are also selected areas, are located in the "Channels" tab on the "Layers" window. Next to each of them is an emblem that displays the selection in miniature: the area itself is white, and everything else is black. Access to each channel is carried out using hot keys, the combinations of which are indicated in the same place, in the channel list to the right of each of them. To deselect the selection, use the Ctrl + D keys.
Step 4
To load a previously saved channel, choose Selection> Load Selection. In the window that appears, pay attention to the fields "Document" (if you are currently working in several documents) and "Channel" (if there are several selected areas in a particular document). After selecting the desired alpha channel, click "OK".
Step 5
If you want to save the result, click the "File" menu item, then the "Save As" button (or the Shift + Ctrl + S combination), select the path, write the file name, specify Jpeg in the "Files of type" field and click "Save" …
