Instructor: Prof. Takehiko Nagakura
Last modified: 2011.02.03. by TN
All rights reserved.
Demo 1The following example blends two images together using alpha channels. |
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1 | Open both marble.jpg and king.jpg in Photoshop. |
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2 |
In king.jpg, create a new channel by switching to the Channels
palette (the tab usually found next to Layers tab) and clicking
on the squared icon at the bottom of the palatte (usually found next to the
trash can icon). Or you can use the pull-down menu (triangle icon)
at the top-right of the palette and choose New Channel.
Rename the new channel to "gradient mask". |
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3 | With the gradient mask channel active, create a gradient which is black on the bottom and white on top. For this, make sure that you have fore ground color black andback ground color white, choose the gradient tool from the tool bar, and drag a line from a point on your image to another. |
| 4 | To view the image of king.jpg, click the RGB channel at the top row of Channels palette. This brings you back to the normal layer editing mode. | |
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5 |
To load the channel as selection, go to Select > Load Selection... > Document should be king.jpg and Channel should be gradient mask. After clicking OK, you should have dashed border area covering the top half of the image. This area indicates the selected area with more than 50% transparency, but the rest of the area with lower transparency is also implicityly included in the selection. |
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6 | Copy (Ctrl-C) the selection, and paste (Ctrl-V) it into the other image, marble.jpg. Use the Move Tool to align the new layer with the top of the image. |