For censorship or privacy, you can use the blur_faces filter which will fog all faces found in the image by applying Gaussian blur.
|TH||threshold of the face detection algorithm||0.15||threshold of the face detection algorithm|
|S||blur sigma (Gaussian distribution)||1000|
|CR||corner radius of the masking shape
(use max for an ellipse)
|0||corner radius of the masking shape
use max for an ellipse
If you are unsure which settings you should use, you can start with default values (blur_faces=1).
Face blurring is most effective for images with enough spatial resolution and sufficiently high quality - images larger than 300 pixels and with enough detail.