Some PS saving help for LYRIC!

[evopete]

Ok I should have taken notes on this one, but when saving files for use on LYRIC, from Photshop, and I need the alpha channel for KEYING. Do I need only the alpha channel opresent and delete all other channels, or do I need on only make the Alpha channel visable, and the rest non visable? I hope I made sense, if I didn't PS school here I come :gap:

Pete

[Greg Lennon]

Well, here's the long & short of it. Well, I guess mostly the long of it:

It depends on how you're importing the Photoshop file. If you're importing the layered file into Lyric then the alpha channel is irrelivant...Lyric will use the transparency information from each layer to make that layer in Lyric keyable.

As for channels, you'll always leave your RGB, Red, Green & Blue channels present. If you've got a file in Photoshop and you're saving it out as a Targa file, for example, then the Alpha channel becomes critical. Merge the layers you want in Photoshop, right-click the thumbnail in the layers palette and choose 'select layer transparency'. Then select the 'channels' tab (right next to the layers palette) and press the 'save selection as channel' button at the bottom of that palette (the rectangle with a circle in it). You've now created an alpha channel.

There's a few important things of which you need to be aware with regards to Photoshop and alpha channels (especially when creating content for video):

If you don't give Photoshop a background (ie you leave the checkerboard pattern 'visible' in your image) Photoshop will flatten that image over white. The result will be a thin white line around your keyable graphic (the areas where anti-aliasing occur) when you import it into Lyric. This looks bad and annoying people like me will mock you when they see your graphics on air.
Giving your graphic a black background is better than nothing (ie white), but it won't be perfect. A little harder for folks to ridicule, but not impossible. The real problem comes when you've got graphics with varying transparencies (ie gradients or soft edges). This is where both the white or black backgrounds produce horrendously ugly & innacurate graphics in the video world.
There's a trick to creating graphics like this for video. Try the following exercise:

Create a new image in PS (Cntl-N), make it 700 pixels wide & 100 pixels high at 72dpi. Make your foreground color blue. Select the gradient tool (press 'G'). Make sure the gradient settings in the toolbar are for a gradient that goes from the foreground to transparent. Make the gradient go in a straight line from left to right (hold the shift button down to constrain it to a straight line). Select the layer transparency and save the alpha channel as per above. Save it as a TGA file and call it BlueRampWrong01.tga.
Now create a new layer in your image (below your gradient layer)and fill it completely with black (make your background color black, then CNTL-Backspace to fill the layer). Now save this as a TGA file and call it BlueRampWrong02.tga.
Now select your blue ramp layer and fill the layer entirely with blue (your foreground color...ALT-Backspace will do this assuming you've still got the blue selected as your foreground). Save this as BlueRampCorrect.tga.
Import all three targa files into your Lyric canvas in the order in which you created them, positioned top to bottom. XFer them to your output and look at them keyed over video in your switcher. Note that BlueRampWrong01.tga ramps from solid blue to sort of a greyish blue to transparent (a result of having the white Photoshop-flattened background in the file). BlueRampWrong02.tga ramps from solid blue to kind of black-ish blue to transparent. BlueRampCorrect.tga ramps perfectly from solid blue to transparent with no change in the color from one end to the other.

The short explanation for what's happening here is to understand that all your transparency settings should happen only in your ALPHA CHANNEL, not in the layer of your PSD file. The print graphics guy at your station will look at your PSD files and say they're all wrong, but you'll know better. In fact, if you just look at them in Photoshop they will in fact appear completely wrong...however your graphics will key perfectly and you'll force people like me to turn to ridiculing your on-air talent instead of your graphic presentation.




Hope this helps...
Greg

[evopete]

Seriously Greg,
YOU ARE A AMAZING. Wow, that is the exact explanatin that I needed. This should totally be a sticky or something, I am sure many Graphic guys could really utilize this info. Thanks Greg for the help, and when I get home today I will try your excercises...

[Elizabeth]

I will make this a sticky :)

[erikh]

After merging layers and saving the alpha channel, one could also remove the transparency from the layer to avoid the dark edges effect when keyed. The sloppy way would be to just make 20 copies of the layer. There are also a couple free plugins to do it right...the PhotoFreebies "Remove Transparency" filter (Windows only), or use the Filter Foundry filter and just set A=255.

I like to just save a .png with no background and not worry about creating the alpha channel.

[Elizabeth]

I finally made this a KB article.

[evopete]

Just want everyone to know that I still use this thread...

[kurt murphy]

Also, if you have After Effects, just bring in the PS layered file with its dissolved ramps and shadows and drag it to a new comp. Export a frame (command/option-s) and save as a Targa file. Make sure that you select Millions of Colors+ (this makes the alpha) AND that you use a Straight (not premultiplied) key. After Effects will export a pristine RGB and alpha channel in less than a second.

[erikh]

Over the past year I've decided that what I described as the sloppy way to make your merged fill graphic fully opaque works the best. Just {duplicate layer; merge down} and repeat 14 or 15 times. Works on any platform (unlike one of the plugins I mentioned) and on pretty ancient versions of PS, and is simple enough to make into actions. I still prefer making a .png but I've had to make a lot of targas for the old Maxine too.