In this video editing tutorial, we will learn how to blur/pixelate a face and track a moving face by creating a moving mask to track one or multiple people who need their identity concealed. We will also take a look at using pitch shifter and a couple high/low pass filters to garble and alter somebody’s voice to the point where it is unrecognizable. If you need to conceal a person’s identity, whether visual or audio, this it the Premiere Pro tutorial for you!
Find the Subject
The first step I take is to find where in my footage the subject enters the frame and use the Slice Tool to slice at the exact moment the subject enters the frame and the exact frame where the subject exits the frame. This should give us a clip right in the context of our larger clip. We will work on this clip.
Add the Mosaic Effect
Open the Effects Panel and go Video Effects> Stylize>Mosaic and drag that effect out and drop it on our little clip and set the Horizontal and Vertical cell size to 25 or so. Just make sure the cells are large enough to make it impossible to see details on the person’s face.
Masking and Tracking the Face
Over in the Effect Controls Panel, you will see a little circle icon. Click this to create an ellipse mask and use the handles on the edges of this mask to draw a shape that will cover the subject’s face over in the video monitor. Use the Forward and Backward facing play buttons to track the mask forward and backward and Premiere will automatically track the face of your subject. Check out the video around the 02:53 mark to see how I do this and further customize the tracking if Premiere can’t quite follow your subject’s face.
Use Pitch Shifter to Disguise a Voice in Premiere Pro
To disguise a voice in Premiere Pro, I like to slow my video down to a speed of about 95% or so and then add a High and Low Pass filter to the audio track and then add a Pitch Shifter and drop the pitch of the voice by about 3-7 semi-tones depending on the voice. Check out the video at the top of this post to see exact how I concealed the visual and audible identity of my subjects! Thanks for checking this out!