Mask from transparent Photoshop image

Question

Targeting player 7, is there a straightforward way to make a
shape from the non-transparent areas of an imported bitmap? By
straightforward I mean other than breaking apart the bitmap and
selecting the non-transparent areas with the magic wand and
deleting them. I have a number of product images with transparent
backgrounds and I want to make masks the same shape as the
products.

Answer 1

Hello Bob,
> Thanks for the input. Maybe it's time to move on from
Flash 7! The
> blend mode approach doesn't quite do what I want -
unless I've
> misunderstood something. This is what I'm trying to do:
>
> this.blendMode = "layer";
> bitmap_mc.blendMode = "erase";
> maskee_mc.setMask(bitmap_mc);
> Without the 3rd line, bitmap_mc successfully knocks it's
own shape
> out of mcs below it. But when set as a mask it knocks
out it's
> containing rectangle. If instead of blend I manually
delete the
> "transparent" areas from the bitmap I get the required
result. It's
> difficult to understand the difference between the
bitmap I produce
> this way and the original imported .psd file with the
same transparent
> areas.
You are absolutely right about concealing difference between
blend feature
and actual transparency in imported images (.psd, .png).
However, I suppose this was just a first step of adobe
(initially macromedia
team) back to Director ideas of masking (it was perfectly
marvelous there).
When you need to mask an image with some predefined mask it's
much easier
to use images that already have transparency (.png is the
choice). Nevertheless,
think of situation when you are dynamically (via AS) building
complex mask:
you can use BitmapData class to scan, for example, an image
and build your
mask on the basis of this scan with further option to apply
different blending
modes on the fly. Need more vivid example? No problemo: for
instace, you
are making some dynamic gallery or e-shop frontend, all your
photos are initially
made for easier keying feature (on some solid color
background. most often
green or blue), and you need to use these photos to be
displayed semi-transparent.
Of couse, you can use photoshop (processing images like a
sort of a robot...),
but you can use the method I've described above (letting you
flash work over
the photos and making it possible for you to spend much more
time with sweet
chicks d^_^b or beer, or whatever you like). The choice is
yours )))