Creating alpha channels

Say I've got a shot of still image.
It's a white spaceship against a black background.
The clip has no alpha and is a photo still rendered as a dv clip.
Can I somehow make it so the black part of the shot becomes transparent, leaving the white spaceship, so that a layer underneath shows in place of the black part of the shot?
I'm not clear if it's possible in fcp to create an alpha channel on a clip that didn't have one.
Thanks!

one thing you can do is use the chroma key filter and key out the black bg. That will get rid of it. If the whole point is to use the clip out of final cut (in shake, after effects, etc.) and you need an alpha layer, you have to export the clip. put it on it's own timeline and export using quicktime conversion. Choose quicktime, then in the options, select 'animation' as the compression type. Under the compression menu, choose milions of colors +.
export that and you will retain the alpha layer that you keyed out.
good luck.

Similar Messages

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.
Is there a way to do this "automatically" with Photoshop 7.0.1 (the only version I have access to) under MacOS X 10.4.11?

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...

ProRes 4444 with BOTH Alpha Channel AND Timecode?

Recently did a large project of creating alpha channels from green screen footage.
Made the timelines 4444 and tried to output.
If I export as Quicktime, I get the timecode but not the Alpha channel.
If I export as Quicktime Conversion, I can get the Alpha channel, but not the timecode.
Am I doing something fundamentally wrong?
Is there a way to get both on the same output?
Like I said, this project is large -- 91 files -- and it takes more than 8 hours to export out either way even on a current 6 core machine.
What I really do NOT want to have to do is some crazy copy and paste of the timecode information from two separate exports.

You said, "'export as Quicktime' is a very vague description."
Actually, it's not.
A person only has a few choices in Final Cut Pro. If you want to get really specific;
File > Export > QuckTime Movie...
Or
File > Export > Using QuickTime Conversion...
That's it!
With the first and ONLY the first, it will export whatever is on your timeline and you can get Timecode, but I can't figure out a way to make it output the Alpha channel with it.
With the other, you can get any sort of converted output you can input, including ProRes 4444 and Alpha, but unfortunately not the Timecode track.
UNLESS some Guru out there knows some sort of trick.
I'm hoping to find somebody that knows one.

How to save a Targa with Alpha Channels in PSE9

I have PSE9 and need to create an image without the background (mk background Alpha Channel) and save as Targa. I can edit the pic, save at 32 at 200k but PSE9 does not allow to save/create Alpha Channel. How do I make the (background an) alpha channel and save as Targa?

Save your selection using Select>Save Selection, which creates a new channel (i named it Alpha 1 below)
Pse 9 will save the channel when using the 32 bits/pixel in the targa options dialog.

Photoshop not presenting alpha channel as expected (like I'm seeing GIMP does)

Greetings,
I have a need to edit the channels independently (the values in my image mean things numerically rather than just what it looks like visually - so I need to edit the grayscale values in each of the R - G - B - and A channels seperately).
I've searched through google and other forum posts and others bring up the concept of not understanding alpha versus transparency - but I have yet to see an explanation that fully explains what I'm experiencing.
The closest was http://forums.adobe.com/message/2563436#2563436 But while I saw the exact same symptoms being described, the specific question was never really answered.
Hopefully, a concrete example with pictures will be able to communicate the issue and solicit a useful explanation and/or solution.
While, I'm specifically working with an RGBA image, below is a screenshot of a PNG that demonstrates the exact same behavior or symptom. The screenshot below represents the PNG inside GIMP and PS CS4. BTW, if you'd like to see or play with the image yourself, you can grab the same image at http://www.libpng.org/pub/png/img_png/imgcomp-440x330.png
GIMP, interestingly enough loads the PNG as expected - I see the transparency of the image treated as a true alpha channel.
In PS CS4 however, the transparency seems to be somehow embedded in the Red - Green - and Blue channels; but NO seperate alpha channel.
I can create the alpha channel through Select - Load Selection - Layer 0 Transparency - and pasting that into a newly created alpha channel - but the color channels still have the transparency mixture symptom - rather than showing the JUST the color component of that channel. (Note the channel differences of the GIMP's Red Channel versus PS's Red Channel - Said in another way, the yellow ball in the upper left of the image should have a red value of 255, so the Red Channels grayscale upper left ball should be white like it is in GIMP, rather than Gray as it is in PS).
I never thought I'd experience GIMP being superior to Photoshop - so hopefully somebody can shed light on what is going on - what configuration I may have myself in - or a process to get the channels seperated out in the manner I wish to work with them. Furthermore, maybe somebody can educate the Photoshop community what the difference between transparency and alpha[transparency] is. I haven't found quite the right explanation that makes the light go off in my head yet. As best as I have gleened "Alpha", which can be applied to any kind of channel, typically is in reference to transparency - and is applied as a document-whole transparency (as opposed to transparencies applied at a layer level - such as a layer mask).

I think I've finally determined that modern Photoshops have gone in a different direction that I feel "Alpha" should be done.
(good or bad).
Here are the steps and/or details of how I arrived at that conclusion.
If nothing else this has been very educational on how Photoshop treats alpha.
- Import your alpha'd PNG with SuperPNG format (see above on how to make sure you use the SuperPNG plugin to load the .png).
- In the SuperPNG dialog select "Alpha appears as seperate channel"
- Create a layer from the Background and Delete the original Background
(since the Background is locked and we can't edit the Background - we want to add a layer mask based on the alpha)
- Ctrl-Left Select the "Alpha 1" channel - Ctrl-C - and hit the "Add Layer Mask" button (square with the circle at the bottom of the LAYERS rollout)
- For this demo and clarity, I went ahead and deleted the alpha "Alpha 1" that came in through the SuperPNG plugin
So now I have the Layers like I kindof expected the main document to just come in as (kindof though - it is presented in a Layer Mask rather than Alpha Channel).
What is interesting - which you'll see if you toggle the layer mask on and off
(shift-click the mask thumbnail in the layer)
Note how the thumbnails in the channel views render differently during the toggle.
When the mask is off you see the individual color channels like I expect - black where there is an absence of that color.
However when you enable the layer mask - the individual color channels show in semi-transparent/checkerboard.
So this is exactly how the color channels are presented when loading in a .png (WITHOUT the SuperPNG plugin) or an .rgba
..you get the semitransparent views of the color channels - BUT the difference is - you have no way to directly see or edit the Alpha channel.
nor are the color channels represented as completely opaque versions.
What is really interesting - it is there though - if you Ctrl-Left Select the layer, Ctrl-C, and "Add Channel Mask" - you'll get the Alpha mask.
HOWEVER, the big issue is that you can't toggle or edit the Color-Channels like the Layer counterpart above;
they are ALWAYS the semitransparent/checkboard version; AND now we basically are double applying transparency
(due to the still embedded alpha/transparency AND the newly create "Alpha 1" channel)
I think this a bug (or a poor reimplementation of modern Photoshop releases; I believe older Photoshops used to break out Alpha in the "arguably correct" way - and in fact the way GIMP currently does).
Or maybe there are other explanations - like abstracting some of this complexity away from less advance users, etc?
So the SuperPNG plugin was useful in experimenting, understanding, and demonstrating what is going on.
However, if I'm trying to read in .rgba directly, I don't think I have a way of making the "Alpha appear as a seperate channel" as I think any image with "alpha" component should.
(png, tiff, rgba, etc).

How do i create an alpha channel to place into edge animate?

HowHow do i create an alpha channel compatible with edge animate?

I don't use Edge, but since it is a web tool it stands to reason it would use standard web techniques, meaning it would rely on built-in transparency functions of formats like PNG and GIF, which you can easily produce by using Save for Web after creating normal transparency on a layer in Photoshop. No extra Alpha channel or otehr extra steps required. Perhaps Edge even has some stuff that does the conversion on the fly by allowing you to open a native PSD like in Dreamweaver, but beyond that I don't see what else it could/ would do - all the features it can provide are limited by standard specifications for HTML, CSS and JavaScript. There is simply no way to do something sensible with a TIFF in a browser, if you get my meaning .
Mylenium

How do I create or export a logo in Illustrator CS5 with an alpha channel to use in Final Cut Pro 6?

To anyone who can help:
I have created a logo using Illustrator CS5 and need to import it into a video sequence in Final Cut Pro 6. The logo has a transparent background. It seems FCP 6 will import both native .ai files as well as .tiff files, but when I open them in FCP 6, the alpha channel (transparent background) is no longer there; there is just the logo over a white background. Is there a setting or step I am missing?
Shaun MacLellan

I have to insert AI images into Final Cut Pro and Motion quite frequently.
The most effective way I've found to get an AI image into Final Cut is to:
1. Select/copy all the objects in the AI doc.
2. Create a new file with a transparent background in Photoshop and paste.
3. Merge the layers and make sure the mode is RGB.
4. Save out as a .PNG or .PSD.
5. Drag the result into Final Cut (or Motion).
6. Resize and position the result to taste.
Attempting to export directly from AI to .PSD or .PNG is a wasted effort and the results may not even be recognized by Final Cut.
Yes, it requires Photoshop and it is a few extra steps...but it works like a charm.
Additionally, when creating a new file in Photoshop, you may want to initially set its size to match the aspect ratio of your video. For example, if you're making an HD video, you might set the size to 1280x720 and position the AI elements where they are supposed to be in frame. You can set the AI elements in accurately by cutting and pasting a frame from your video into Photoshop and positioning the AI elements in place on another layer above the video layer. Delete the video layer before saving out as a .PNG or .PSD and it will appear in Final Cut exactly where it should be.

Creating an alpha channel in an odd way ?

My question is about the functionality of After Effects. I highly doubt it's possible but would like to run it through people who would know. My question may not be clear as I'm not sure how to describe it!
I'm wondering if I can create an alpha channel using the still background of a shot, as an alternative to green screens and making it easier outdoors without needing crazy lights.
Here's an example. Say you film yourself using a tripod (so the background is still) walking away from a building and want to add an explosion behind you without masking every frame, would you be able to have it recognize the background using a picture without you in it or a still that has the same lighting, and using that to automatically have it differentiate that background from you thus creating an alpha channel or an automatic mask...
Thanks

For a Difference Matte to work absolutely nothing can be moving in the scene. Difference Matte will not work with compressed original footage. I know I've tried many times. If the wind is blowing in the grass or the trees are moving the Difference Matte will not work.
if you are planning this kind of shot then the best thing to do is try to find some good areas of contrast in the shot so you can create a procedural matte. A little garbage matte and a procedural matte created by adjusting levels or color or hue can create a much better matte and does not rely on the pixels being exactly the same on every frame.
Even easier is a carefully planned shot and Roto brush.

Create Photoshop stil with alpha channel?

I'm using dvMatte Pro3 to strip out the green screen.
I'd like to be able to generate a Photoshop CS4 file with the alpha channel, so that I could composite the background in Photoshop, but I haven't been able to get that to work.
Is there a way to do this, or do I generate a matte along with the still and layer them in Photoshop?
BTW - I've also had a bit of trouble directly taking a sequence of a freeze frame out to a Photoshop CS4 file. It creates one using 'Export using Quicktime Converstion', but it is only 100k and not a valid Photoshop file.
I've had to create a new freeze frame from the sequence (with my background rendered into the shot), and then export this freeze frame (not the sequence) using 'Export using Quicktime Converstion' to get a workable Photoshop file.
Always interested in a better method?

Les Caudle wrote:
However, I'm not getting a PSD with the background as an alpha channel.
You won't. The foreground contains the alpha channel. The background is what appears behind the alpha channel
Here's what I've done.
1. Strip out background in FCP7 with dvMatte Pro. The sequence contains a single freeze frame I wanted to output to Photoshop.
I am assuming your clip is a person standing in front of a green screen and you have keyed out the green. That leaves an alpha channel in the shape of your person.
2. Render sequence.
this is probably the mistake you are making although FCP6 and 7 were said to have fixed the export issue. You are attempting to export a rendered sequence. The matte has been filled so there is no longer an alpha channel.
3. As I've been unable to export the sequence to Photoshop (just creates a 100k file that is not a PSD), I take a freeze frame of my render.
I still don't know what this means; telling me the same thing twice is not an explanation so I will disregard is irrelevant.
4. I select this 'freeze frame' and Export using Quicktime Converstion, set the type to image, set it to Photoshop and to Millions+.
All you are doing is exporting a full frame of video. It has no alpha channel. but even if you separated the two video layers, your background plate still has no alpha channel that contains any valid information. It will appear completely solid white if you viewed it using the alpha button in the Canvas.
5. The resulting PSD has the background stripped out, but it is black, not transparent. So, I'm obviously doing something wrong?
Possibly the 'freeze frame' I create is not in 'millions+' - so when it is exported there is no alpha?
I'm totally lost now, why do you care about the foreground? I thought you wanted the background with an alpha? Are you looking at the alpha-only view in Photoshop?
I take full responsibility and apologize for not being able to see through any translation errors that are creeping into our discussion. Like most Americans, I only know English (and enough Spanish to be able stay out of trouble at a Mexican restaurant).
bogiesan

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.

Paint effect to create an alpha channel

Can one use the paint effect in Motion 3 to create an alpha channel. I want to be able to create a matte around someones eye. I wanted to be able to create my key by painting it on. Will paint effect do this or do I need to use shake. Or is there another way of achieving this with Motion 3.

This is really easy to do and there might be an even easier way, but this i how I did it:-
1) Create a group with your image you want to mask
2) Add an image mask to your image and toggle to invert mask and stencil off
3) Create another group but turn the visibilty off
4) drop this group into the image mask
5) Within this group, select the paint stroke tool basic solid and paint away!
Be careful you don't have the write on enabled as the mask will draw on, but maybe thats what you want!
Peter
MacPro 3G 6G RAM FCP6 M3 FxF1.06 Mac OS X (10.4.9) XSR Decklink & loads of cool new plugins, Gaggia TD auto

I'm creating a lower third in Motion and importing into FCP X, but the alpha channel is gone when I import into FCP. What am I doing wring?

I'm trying to export from Motion 5 with an alpha channel, but in FCP X the alpha is gone. What do I do?

if you're exporting video animation out of Motion and you need transparency, then you need to make sure that the codec used is ProRes 4444. There are no other options. From the Share > Export dialog, the default Export option is usually "Same as Source." In Motion, that *should* be PR4x4. You can double check that setting by clicking the summary button and reading the last line.
You also need to make sure under the Render section that Color + Alpha is selected (that should also be the default setting.)
However, most of all, you're really wasting your time going about it this way. If you started a Title project in Motion, all you have to do is Save and give the project a Name; pick a category or create a new one. In FCPX, in the Titles browser, look for the category you used and find the project name and drag it onto the storyline.
You have the option of picking parameters in your motion project that you can "publish" to FCPX (things like the lower third background color, text color, positioning, etc... almost every parameter is publishable to FCPX allowing you to customize the project *inside* FCPX.) Any parameter you publish in Motion will be in the Title Inspector in FCPX. You do not have to "bake" your lower third in Motion before using it in FCPX. You can pretty much turn your project into an FCPX plugin.
If you didn't start a Title project, you can still build your lower third as an FCPX Generator. Go to the File menu and Publish Template... In the dialog box, make sure you check Publish As Final Cut Generator. Give the project a Name and select a category (you'll need to wait a few seconds until the Categories update to the FCPX categories...) You can create a custom category if you like and save the project. In FCPX, instead of the Titles browser, look for your template/plugin in the Generators > WhateverCategory > YourLowerThird.

Can Photoshop Element 12 create new alpha channels?

Can Photoshop Element 12 create new alpha channels? I wanted to create one to help with blurring the background and I saw the step by step on line, but I can't find where the channel panel is? I have a PC

There is no channel panel in Elements. You could add some paths and channel features with third party add-ons like Elements+, but the real solution is to use a tutorial for Elements, not for Photoshop. There are always several ways to achieve something in Elements or Photoshop. Using alpha channels is only one way to help with blurring the background.

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.
If anything the person is wearing matches the background, for instance, that will be transparent.
After you've created a black/white representation of the "difference", you can add your person clip again to a new group, ⌘-shift-m to add a mask, then drag your difference group into it and set the source to luminance...
make sense?
Patrick

Better Alpha channel handling

I've asked for this a lot: alpha channel saving with PS is terrible, and could use an update. And today, I was embarrassed by a bug that caused our game engine to perform poorly as a result of the way Photoshop handles the alpha channel.
The bug: make a 1024x1024 canvas, give it an opaque alpha channel (100% white, every pixel), then Image Size it down to something smaller, like 128x128. Now look at your alpha channel: grey pixels all along the border. ARRGGGHHH!!!1!1! It interpolated, I'm sure, using black alpha outside the canvas that doesn't actually exist, changing, in a powerful, fundamental way, the nature of the alpha channel. Video cards care about this stuff: 99.9% opaque is not 100% opaque. This is terrible.
The request: That PS intelligently offer better defaults when saving an image with an alpha. Right now, it offers, "What was the last bit depth you saved an image to?" Regardless of the fact that the previous image may have no relationship to the following image being saved, the default offering is always "what I did last time". This enables very easy pruning of alpha channels that should be there, or adding opaque alpha channels that shouldn't be there, bloating the file size.
I'd like PS to determine if an alpha channel is present, and base its default choice on that. If one is present, default to 32-bits. If an alpha channel si not present, default to 24-bits. That easy.
If multiple alpha channels are present, I'd like a dropdown menu to pick which one I want. Right now, if you save a PSD with multiple alpha channels to a 32-bit TGA, it throws all alpha channels away, and saves the image with a solidly opaque alpha channel, the choice no one asked for.
For texture work, or works where the graphics card is the destination, not the printed page, this cavalier handling of alpha channels is definitely not sustainable.
I'd love to never have to ask for this again.

Generally speaking the resize of an image on a layer in which the canvas is exactly the size of the data will result in transparency peeking in around the edge (i.e., I'm agreeing with you here, just using Photoshop terms). I've always thought this was kind of poorly thought-out too. As you say, the algorithm must default to using 0 vs., say, replicating (or "clamping") to the alpha of the pixels right on the edge.
I suppose theoretically, the thinking is that if you were to EXPAND the canvas, the area around the image would be transparent anyway, and a subsequent resampling would then have the same result as the above.
Knowing this, one way to work around the problem would be to create a slightly larger image, then Canvas Size it down to your intended resolution. That way there's layer data beyond the edges with which the resizing algorithm can work. I realize that's probably not a practical solution in general, but a trick to keep up your sleeve if you really do need that 128 x 128 image with alpha solid to the edge.
-Noel

Creating alpha channels

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