In this tutorial, we will learn how to export
a TIF graphic from Adobe Photoshop with an alpha channel that
PowerPoint can import. I have used Adobe Photoshop 6 on Windows
XP Professional.
For this example I created (File | New)
a new file in Photoshop with a transparent background.
Using Photoshop's shape tool, just draw
any shape to fill the empty document.
Choose Layer | Rasterize | Shape.
Choose any color for the foreground and
click the Gradient button from Photoshop's tools - within options
(the toolbar below the menu), choose the foreground to transparent
gradient.
In the Layers window, Ctrl-click
the layer that contains your shape so that all non-transparent
areas are selected.
Press the Delete button on your keyboard
- you now have an empty screen with a selection (shown as 'marching
ants').
Drag in any direction with the gradient
tool to create a fill that spans from opaque to transparent.
Alternatively, you can also use any other non-transparent gradient
or a solid fill color. Repeat and experiment until you are
satisfied.
Press Ctrl-D to deselect everything -
Ctrl-click the layer again in the Layers tab window to select
the entire transparency gamut.
Go to the Channels tab and select 'Create
New Channel' from the flyout menu. Click OK for the default
name that Photoshop chooses for the new channel.
Photoshop will present you with a black
background and a selection comprising our shape. Click Alt-Backspace
to fill the transparency gamut with white. Press Ctrl-D to
deselect.
Go back to the Layers tab and choose File | Save As...
In the file format drop down box, choose
TIFF. Check the 'Alpha Channels' box in the Save Options if
it is disabled.
In the next dialog box, choose IBM PC
for the Byte Order and enable LZW Compression.
Back in PowerPoint, just insert the exported
TIF using the Insert | Picture command - the screenshot below
shows you how the transparent areas reveal themselves.
