BLUR EDGES

The Blur Edges effect blurs an image around a specified radius. 

SLIDERS

X & Y - Control the horizontal and vertical position of the area which remains sharp.  (In iMovie 2.1.1 and higher, the X and Y values are set by picking a point in the small preview window.)

Radius - Controls the radius of the unaffected area.

USAGE

Blur Edges will blur an image outside a circle defined by the user.  The larger the radius, the larger the area that is not affected by the blur.  This effect can be used to draw attention to a particular object in a shot.
INDEX
EDGE DETECTOR

The Edge Detector effect finds sharp boundaries between areas of different color in the original video and generates video which looks like a black and white sketch. 

SLIDERS

Sensitivity - The higher the sensitivity the more edges will be found.  At very high settings even the differences of color caused by slight noise or static in the video may be considered an "edge."

Radius - Controls the amount of blur applied to the original image before looking for edges.  This reduces the noise or  static in the image and can make the edge detector work better, but it can also make the resulting image less sharp.

USAGE

Edge Detector is an effect that allows the user to make an image that looks like a drawing.