If you are looking for a powerful Chroma Keyer to remove any type of background from a heavily compressed clip, then probably you should consider using the Keyer effect in Final Cut-X as a viable option. Keep in mind that the task might become even more laborious if instead of a blue or green background you have to deal with a white one.
Below Mark Spencer from Ripple Training will showcase how far he can go in this challenge by utilizing only the available functionality that comes with FCP-X and the excellent Keyer effect in particular. Prepare to spend less than five minutes on this tutorial and a lot of tweaking afterwards if you decide to take up this challenge on your own.
To start off, apply the Keyer effect on your clip. In the Viewer hold down the Shift key and draw a box on the white background. If the background is evenly lit it really doesn’t matter how large the box will be or where it will be placed as long as it doesn’t touch your subject in the foreground.
After, hold down the Command key and drag an edge sample across the hair of your subject. Then switch to the Matte View and increase the Fill Holes’ slider slightly to make the inside of the matte white. Then increase the edge distance all the way right to get back the detail into the hair. Skim the clip and if you still see transparent areas move on further with the other settings.
In the Colour Selection tools, you can try adjusting the Luma curve of your image along with the Luma Rolloff setting. If the problems in the hair still persist close the Color Selection tools and open the Matte Tools. In this particular case, Mark sets the Shrink/Expand setting to -5, and Soften slider to 1.0Typically, the latter settings will introduce more transparency in the mask and will also help to eliminate the white fringing.
Next, open the Light Wrap settings, switch to the Matte View again and skim through the clip one more time. If there are still visible transparency areas in your matte you can try to eliminate those by creating a smaller white matte inside the main one. Switch back to the Composite View, copy the main clip and then paste it as a Connected clip on top.
Select the connected clip and in the Inspector increase Fill Holes to 10 and set the Edge Distance to 0. This way you will create a solid white matte. Keep in mind, though, that this matte should be smaller than the main one in the lower clip. In the Matte Tools set Shrink/Expand Settings to -40, and set Soften and Erode settings to 10 respectively.
Voila! Now, when you switch to the Composite view and skim through the clip you should see the final results. And, remember that if you want to make this key work perfectly for you, you’ll need to keyframe the various parameters of the Keyer frame by frame to get the best possible results.