Hi,

Just getting to grips with Prem 6.5 and wondering why I can't manage to
superimpose any of my images onto video via the white alpha matte key.

I'm aware, I think, that the image must be of a certain property to allow
the superimposition, but am not sure what this propert is or how I can
convert an image to posess it.

I have Photoshop 7.0 BTW.

Thanks in advance guys,

Tom.

Just worked out that the RGB difference seems to perform the same job, is
this an OK alternative?


"Tom" wrote in message
...
Hi,

Just getting to grips with Prem 6.5 and wondering why I can't manage to
superimpose any of my images onto video via the white alpha matte key.

I'm aware, I think, that the image must be of a certain property to allow
the superimposition, but am not sure what this propert is or how I can
convert an image to posess it.

I have Photoshop 7.0 BTW.

Thanks in advance guys,

Tom.

"Tom" wrote in message ...
Hi,

Just getting to grips with Prem 6.5 and wondering why I can't manage to
superimpose any of my images onto video via the white alpha matte key.

I'm aware, I think, that the image must be of a certain property to allow
the superimposition, but am not sure what this propert is or how I can
convert an image to posess it.

I have Photoshop 7.0 BTW.

Did you create and save an alpha channel in Photoshop?
Not all file formats will save with an alpha channel, and,
even those that do, can also save without an alpha channel.
load your image in Photoshop, and then look at the channels tab.
there should be at least 5 lines RGB is the full image, then there
should be separate R,G,and B, channels below that, and then
an alpha channel below that. The alpha will be black in the areas
that are to be transparent, and white in areas that are solid. If
there are gray parts, then they will be partially transparent.
If there is an alpha channel, but it is all white, then you didn't
properly prepare the alpha channel. If this is the case, then
delete the all white channel. Note that there should only be
one alpha channel, if there is more than one, then delete them.

You need a "selection" to create an alpha channel. Once you
have created a selection, then you can "save selection, and
choose "new". If this all worked, you should be able to go back
to channels, and see an alpha channel, as described above,
at the bottom of the channels pallet.

When you save the picture, there should be a check box that
says save alpha (or something like that) make sure it is checked.
When you save, a little box will pop up that ask for the bit depth
of the picture, choose 32. This image should perform correctly
in Premiere. Of course, it will have to be on layer 2 or above.

Another way to go would be to make the background part of your
image green, or blue and then use chroma key it. This is
especially useful when you want to key an animation over video.

Another approach would be to save your Photoshop picture in
the "PSD" format. When you load the PSD into Premiere it
will ask if you want to load the merged image, or any single layer.
When you load a layer, it will come in with the alpha matte that
is on that layer. If you have some layers that you need to key,
and others that are just being stored (or used for a different key).
then you need to create a merged layer that contains everything
you want to show in the key. Do a "select all" then do a copy
merged, and a paste. This will create a new layer that contains
everything. Take care to give your layers meaningful names,
or you won't be able to tell which layer to load into Premiere.

Also take note that it is best not to alter the layers (names
or number of layers) of the PSD file once you load it into
Aftereffects or Premiere. You can change a layer's contents.

That means you can paint or do effects on any layer, as long
as you don't add layers. If you need to add layers to make
your changes, then you need to keep track of your original
layers. Before saving the PSD file, you should highlight an
original layer's name, and then link your new layers to that
layer and the do a "merge linked", to get back to the original
number of layers while maintain the layer names. If you NEED to
add layers, then you need to remove the original image and
reload your new version image.

David