Can someone help me out and tell me how to take a logo and subtract all colours but white to use as a title in video? So that the blacks will be the raw video in the background. I was thinking a luma key?
What software are you using for the logo design? If it's Illustrator, go to Type>Create Outlines to convert the text to paths. Then move this over your shape and select both the outlined text and the shape. Then go to Object>Compound Paths>Make. This will knock out your shape with the text.
Hello future me,
I had no expectations for you. So anything you have done is a plus for both of us. Good job! -iAfterBang
In Photoshop or gimp just use the background eraser to delete the black part, then you'll be left with white logo and checker background (meaning its transparent) and save as a PNG and you're good to go.
If you have a white on black logo or vice versa, you can just go (in editing program) to the blending modes (under Opacity in Premiere) and select "Lighten" and it will automatically subtract anything black.
If you use photoshop there is an even easier way then using the eraser. Select the layer with your text, go to the select menu then select couloir range, then just select the black and then you can layer via cut. Delete the new layer an you are left with just your text. If you then need an alpha channel which some program's need, just right click the layer and select pixels. Then go to channels and create a new layer. Then if you press shift f5 and choose full with white you create a perfect alpha channel. You can then just say this as a png or tiff and you will have your text with an alpha channel built in.