Photoshop Tutorials - Editing the Selections in Alpha-Channels
Editing the Selections in Alpha-Channels
Now we will try to edit the channel that contains our selection.
In Channels palette select the alpha-channel you have saved by clicking on it. The image will become black-and white contour and that is no surprise - we are editing the mask. Press D hotkey to set default foreground and background colors (black and white). Then move with the brush over the area that is white. I would like to remind you that painting with black color removes from selection while the white color adds to selection. Therefore, you have unlimited control over the selection shape in Alpha-channel. But do not forget to use proper colors.
Now with the History palette come back to the moment when you did not edit Alpha 1. Return to RGB channel and load Alpha 1 selection. Fill Alpha 1 selection with the black gradient so that it would slightly change from white on top to dark at the bottom. Let us think about what we did - white color is selection so the top of the image is completely selected while other areas get more and more transparent towards the bottom of the selection. The selection dissolves from top to bottom.
Now let us return to RGB and load our dissolving selection by going to Select > Load Selection > Alpha 1
Open other image In Photoshop and drag the selection there. You will see how the selection merges with the background image at the bottom being transparent.
Using this trick, you can blend any objects after some practice.