Triggers will do what you are asking but probably not as you envision it.
The first trigger needs to do two things...
1) Start your shape to enlarging (Emphasis =>Grow => 200%)
2) Appear your second trigger shape
The second shape should be around the edge of where your picture will
enlarge to. It can be nearly invisible (no border with 99% transparent
fill). It will need to apply the shape shrinker (Emphasis => Grow => 50%)
However, this will not allow you to control during the show the amount of
enlargement. It will simply start the animation.
Is this behavior good enough for your needs?

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Bill Dilworth
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Users helping fellow users.
http://billdilworth.mvps.org
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vestprog2@ Please read the PowerPoint FAQ pages.
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> Hello,
>
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>
> Josh
Josh R - 12 Feb 2007 05:29 GMT
Bill,
It doesn't seem to work because it has to start on a click... and the person
viewing the slide may want to see the blow up view or they may not so I would
at least like them to be able to choose to expand. I know I can create a
hyperlink to another slide with the expanded image and then hyperlink back.
I was just curious to see if there was a way to click (or even better just
roll the mouse over the image) and have it expand (without digital artifacts)
click or roll you mouse off the image and have the original slide, just as it
was before.
Josh
> Triggers will do what you are asking but probably not as you envision it.
>
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> >
> > Josh
Josh R - 12 Feb 2007 05:53 GMT
Bill,
I think I have a work around with action settings and mousing over... I can
fool by linking to a seperate hidden slide with the expanded end-state and
then link back to the original slide. It is a quick fix but it would be cool
if PPT had this type of feature naturally.
Josh
> Triggers will do what you are asking but probably not as you envision it.
>
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> >
> > Josh
hu zhenghui - 12 Feb 2007 18:18 GMT
> Bill,
>
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>
> > > Josh
You may write some VBA code to control the size of image.