8 and 16 bits in grayscale alpha channel

Hello.
When I have an image in 8 bits per channel, its grayscale alpha channel is in 8 bits (256 levels).
But when I have an image in 16 bits per channel, is its grayscale alpha channel in 16 bits (32.768 levels)? They are a lot to make a selection...

Why do alpha channels in 16 bits exist if they are not real?
They are real, you can copy and paste them into a Layer Mask for example instead of loading them.
http://forums.adobe.com/message/4597174#4597174

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Why can't I export a 24 bit PNG with alpha transparency?

I have just upgraded my Macromedia Studio 8 to Adobe CS3, and
it seems that I still can't export a 24 bit png with transparency
from Fireworks (Photoshop can do it, but it's just not suited for
volume graphic production). Anyone know something I don't, or can
someone at least explain why I can have alpha transparency on 8 bit
and 32 bit, but not 24 bit pngs? Currently, I'm planning to export
everything from Fireworks, then batch-process through Photoshop to
reduce from 32 bit to 24 bit, which is just... gah! Words fail
me.

Kathleen13 wrote:
> I have just upgraded my Macromedia Studio 8 to Adobe
CS3, and it seems that I
> still can't export a 24 bit png with transparency from
Fireworks (Photoshop can
> do it, but it's just not suited for volume graphic
production). Anyone know
> something I don't, or can someone at least explain why I
can have alpha
> transparency on 8 bit and 32 bit, but not 24 bit pngs?
Currently, I'm planning
> to export everything from Fireworks, then batch-process
through Photoshop to
> reduce from 32 bit to 24 bit, which is just... gah!
Words fail me.
>
If I'm correct, 8-bit png supports index transparency just
like GIF's
do. 32-bit png's support alpha channel transparency, so you
can get
variable or partial transparency in a full color image(8 bits
for each
color and 8 bits for an alpha channel) and 24-bit png's are
similar
jpegs, only you get lossless compression and no user-defined
settings.
So essentially, when you export a 32-bit png file you are
exporting a 24
bit color image with an 8-bit alpha channel.
Jim Babbage - .:Community MX:. & .:Adobe Community
Expert:.
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No alpha channel wanted

Is it possible that no one else has had this problem? I received no answers to my previous post: Is there any way to change the pixel depth when rendering a TGA sequence? The source material - an HD MOV file - has no alpha but when I render in Compressor, it says: 32-bit pixel depth. Can this be changed to 24-bit? Very frustrating.
best,
d.

It has to be the way I am exporting because when I reimport the clip into FCP again and place something under the alpha channel, it does not appear. How can I export a keyed clip and bring it into Motion to manipulate the alpha channel?

Alpha Channel for graphics

Hi,
I placed a 32 bit targa file with an alpha channel in my project as a drop zone but it retains a white background. Is there anywhere to specify in DVD Studio Pro to recognize the alpha channel or will it not accept an alpha channel? I swear, the manual is totally useless.

I figured this out. In case anyone is wondering....
The Targa with alpha channel wasn't working. But a Photoshop file with the Color Profile of NTSC and saved with a transparent alpha channel background worked.
ciao.

How to create Alpha Channel automatically?

I have a folder containing about 100 TIFF files, each containing an intricate shape against a transparent background.
I need to create an Alpha Channel in each one which replicates the transparent background.
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Record into an action and batch: select layer transparency, save selection as alpha channel. Watch your matting though, as it sounds like these files will be flattened and any feathering in the alpha channel will leads to a fringe of [white? black?]. You could tuck in the alpha channel mask a bit before you save. It depends on the final usage...

Minumum sufficient commands to create PSD containing transparent alpha channel

I was recently typesetting some leaflets in InDesign under time pressure. I had a JPG file with a white background and wanted to create a PSD from it in Photoshop CS5 with an alpha channel making the background transparent.
I managed this in the end by blundering around, but the help file is no help, and the obvious way of creating a layer mask doesn't work.
I'd like to know the minimum sufficient command sequence to do it.
Suppose we've got this in Photoshop, with the bit we want already selected:
Double clicking the background layer and then clicking ADD LAYER MASK looks good, but it doesn't create an alpha channel. It actually creates a channel named "Layer 0 mask" but if you save it in a PSD and then import into InDesign it is not transparent.
There doesn't seem to be a "convert layer mask to alpha channel" command. Nor a "make alpha channel from selection" command.
There is a button at the bottom of the CHANNELS tab that's named "create new channel" and if you click it when a selection is active it does create a new layer named "Alpha 1", but unfortunately it is not the wanted mask but rather just the path of the marching ants.

Yes, this does work. Don't know why it didn't for me yesterday.
There's no need to delete the background because in my example, after unlocking the padlock and adding layer mask, there's only one layer there. It does create, as I said above, an additional channel named "Layer 0 mask" which is what one would want as an alpha channel.
If I SAVE AS PSD, the box to include LAYERS is ticked and the box to include ALPHA CHANNEL is greyed out, but InDesign still treats it as transparent.
If I take the selection and SAVE SELECTION AS NEW CHANNEL, it creates a second channel looking exactly like the "Layer 0 mask" one above, but if I then SAVE AS PSD the box to include ALPHA CHANNEL is ticked. So the channel created by ADD LAYER MASK is of a different ilk than the one created by SAVE SELECTION AS NEW CHANNEL, although this is not apparent from the CHANNELS tab. Slightly confusing.

Making a alpha channel in photoshop elements 5.0

hello so I am making this spray or icon I guess you could call it for counter strike source which is a game I play. But I want to make it so that it has no background and apparently I have been told that I need to make an alpha channel so that I can do that. But every tutorial I can find on the internet is for previous versions which have a channel tab in the layers tab.
How ever elements 5.0 does not that have. Can someone help me with this it is driving me crazy lol I have tried just saving it as a targa file in 32 bit nut it still had that white background :(

Colin 1 and 2, thanks. I enjoy your web sites and learn alot from them and your comments here. I am using selections here mostly as cutouts, I'm not sure of my terminology in this forum yet. I never used photo shop and would not know an alpha channel if it bite me. I have spent much time making a selection/cutout and want to save it. I thought save selection would send it some place like copy command saves in note pad. I now believe I have to save the image with it's multiple layers if I want to use that selection/cutout in another image.
Only if you want to do the same selection into other images at other times do you need to save the selection. Then just drag and drop it across. Colin#2

Problems with Photoshop Alpha Channels

Hi all
Got a job where I want to use alpha channels to cut-out some images in Photoshop and then put them into an ID frame with a black background. Want to use alpha channels rather than a clipping path as I need the edges to be feathered (have applied 2 pixels of feathering to the selection in Photoshop before saving it).
When I do this and drop it into Quark it looks good but when these images are dropped into ID and then the alpha channel is turned on, with the default Threshold and Tolerance settings, it doesn't look good. It looks like a rough approximation of my alpha channel, all the fiddly bits and bezier curves in the selection have been smoothed out and the feathering has gone. Playing with the settings doesn't really seems to help either. If I turn on the alpha channel in the import options when importing then it comes in as expected but I have quite a few images already in the document that I need to turn on the alpha channels for.
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thanks,
Iain

Thanks for your reply Bob. I've confused things with my terminology I think. We're drawing a path round the image, using bezier curves where appropriate, making that work path a selection (feathering the edge in the process) and then saving the selection (as an alpha channel) and then using the feathered alpha channel in Quark/ID to knock-out the background. Not keen on using a PSD with a transparent background at the moment as these are just test files while we show the customer what it will look like if we do cut-outs. We are making a couple of different alpha channels per image, with different settings, which would mean multiple files if we used your method I think. Maybe once we get the approval from the customer we could use PSDs as you describe but I was just wondering why the options for affecting alpha channels after importing the image aren't working as I expected.
Iain

Using the difference between two shots to create an alpha channel

If I were to lock my camera down and first film a shot of a non-moving background (say, my living room), then take another shot of someone walking into the room and sitting on a sofa, could I use the difference between the two shots (the person walking and sitting) to create an alpha channel?
What settings in Motion would I use to get this?

If you really want to do it within Motion, try stacking the clean frame and the the frame with the moving person over each other. Then set the blend mode to Difference for the top clip. You can clean this up a bit with a blur and a threshold filter, but Difference mattes are often a bit iffy.
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make sense?
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Alpha channel weirdness with hardware MPE

To begin, I'm using a GTX 480 with the hack, so I'm not going to complain too loudly it this is a result of using as-yet unsupported hardware. However, I just want to verify with other hardware MPE users (both legit and unsupported) if this issue is happening on other systems.
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First up, 100% opaque text over a background. The edges of the text are... fuzzy, maybe?
Software:
Hardware:
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Thoughts?

I can confirm this.
I do not think its the psd but the Alpha Channel in general.
The colours are off when in MPE (Nvidia GTX 285)
I filed a bug report.

.mov files with alpha channels won't import on Adobe Premiere Pro CC

Just FYI, Apple:
This issue with Quicktime not seeing .mov files in Finder (or I should say, not playing them) is a HUGE problem for anyone who edits video.
If you export a file as .mov in After Effects, and have any transparency (RGB+Alpha channels), there is no way to import them into current projects. None.
PLEASE fix this, as I quite enjoy my job, and don't feel like losing it because my client doesn't understand why they can't have lower thirds in their video I'm contracted to do (and subsequently fires me and finds someone on a Windows rig).
Thanks.

What is up!
Based on my tests, it appears that the Mavericks embedded QT structure no longer considers many of the legacy compression formats to be supported under Mavericks. These formats were, by default, turned off under Lion and Mountain Lion which may indicate that Apple intends to drop even passive native support sometime in the future. Files containing Animation or PNG compressed data are no longer QL compatible and now force automatic QT X v10.3 conversion as mentioned above. Even worse, it appears other commonly used fomats like DV/DV in DV and AIC/PCM in MOV are also being relegated to this group. Luckily, DV/PCM in MOV, HDV/PCM in MOV, and ProRes422/PCM in MOV, along with all of my H.264/AAC/AC3/Chapter M4V distribution/iTunes managed files remain fully compatible with both QL and QT X v10.3 under Maverisks. This last is significant for me since many files containing AC3 as the primary audio stream are no longer QL/QT X v10.3 compatible with certain file extensions and/or container types which now appear to be checked in specific situations. Unfortunatly, what we've seen and learned thus far seems to be just the "tip of the iceberge."

Alpha channel in after effects

Hi all, i hope you can help me.
What i would like to do is to use a black and white .mov file as alpha channel for another .mov file.
Exactly as in photoshop is possible to do with two images.
Someone can indicate me some easy example or say me if my approach is wrong?
For some reason, I tried to replicate so many tutorials about it, without found exactly what i was searching to do, and without success.
Thank you so much!

http://help.adobe.com/en_US/aftereffects/cs/using/WS3878526689cb91655866c1103906c6dea-7cf9 a.html
Mylenium

Layer Mask/Alpha Channel. Visual bug when moving or transforming

Open test file.
Add solid color Adjustment Layer.
Paint a big "X" on its Layer Mask.
Option(alt)+click on the mask icon to see its Alpha Channel.
Now select Move tool and move mask around.
Alpha channel does not display properly when moved or transformed.

Right Jeanne, should have realized.
A good workaround for this, if you want to see the mask as you move or transform, is to just hit the backslash key to see the rubylith of the alpha channel. That displays correctly.
CB

Keying with an alpha channel

I have a client that needs some footage that we shot over green screen delivered to them with the green keyed out and an alpha channel already in place. The end deliverable that they are looking for is the talent over an "invisible" background that they can simply drag and drop into FCP without having to key it themselves.
So my question is, how do I key out the green and an add alpha channel to preserve the "invisibility" of what was once green?
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Thanks!

The most straightforward solution is to export your keyed sequences
to Animation, PNG, or JPEG 2000 using millions of colors +.
Make sure the sequence is NOT RENDERED before you export.
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is that the resulting files are huge and will really bog down your client's
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Forcing CGImageProviderCopyData() to return RGB image without alpha channel

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It would be great if you told us what program you are talking about. And it would be even better if you posted your question in the appropriate product forum, which you may find here:
http://forums.adobe.com/index.jspa?view=discussions
This forum is only for discussions on the forums themselves.

8 and 16 bits in grayscale alpha channel

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