Joe's Filters: Joe's Motion Blur

Joe's Motion Blur is a part of Joe's Filters, a shareware package of utility and image processing tools for Final Cut Pro.

What it does

Joe's Motion Blur started out as a smoother rewrite of Final Cut Pro's Wind Blur plugin. Wind Blur's results were often rough or stepped, and lacked the controls to fix the problem, Joe's Motion Blur offers better control and smoother results. This effect does not create true motion-based blurs, this produces a directional blur across a given linear direction.

New in this version

Joe's motion blur has been updated to blur equally in both directions, and now includes the same channel-targeting options as found in Joe's Channel Blur. The original directionally biased motion blur is still available by unchecking the Center Blur checkbox.

Example Images

Original Image
direction: 90° distance: 75 quality: 6	direction: 230° distance: 45 quality: 5

One of the new additions to Joe's Motion Blur is the ability to center the blur on the original, instead of biasing it to one side or the other. The following examples show the difference in quality, note how the non-centered blur shifts the whole image in the direction of the blur while the centered blur appears to leave the image where it started.

Original Image

Joe's Motion Blur Direction: 75° Distance: 30 Quality: 10 Center Blur: Yes Target: YUV - all

Joe's Motion Blur Direction: 75° Distance: 30 Quality: 10 Center Blur: No Target: YUV - all

Below is a side-by-side comparison of Final Cut Pro's Wind Blur and Joe's Motion Blur. Because Wind Blur doesn't scale correctly in zoomed previews it's blur distance is 200px (4 x 50).

Joe's Channel Blur vs. Joe's Motion Blur

For motion blurs along a pure horizontal or vertical axis Joe's Channel Blur produces significantly faster results. There will be some off-axis softness due to stretching a normal blur, but clips will render at least 10 times faster.

The Controls

• Direction

  The angle of the motion blur. This setting works like an arrow, the gradient fade in the direction specified and extend perpendicularly across the selected angle. Detents are set for negative 90° increments, positive values are unconstrained.

• Distance (0 - 200)

  The distance of the motion blur effect.

• Quality (0 - 10)

  Sets the quality of the blur. This is similar to steps in Wind Blur except it is based on a division of the overall distance. Settings extend up to 10, although I've never needed more than 6. A setting of zero has no effect.

• Center Blur(0 - 10)

  Changes the default behavior between a centered blur effect and a directionally biased (lopsided) blur effect.

• Target

  Chooses the colorspace to use for the following channel switches.

• Luma / Red, Cb / Green, Cr / Blue

  Switches on the blur for the checked channels, the same blur settings will be applied to the channels selected.

Notes on performance

Unfortunately, the FXScript Motion Blur function used in Wind Blur and Joe's Motion Blur is not very efficient, and can increase render times with large Blur Distances and high Quality settings.

One additional aha! about my Motion Blur filter vs. the FCP Wind Blur; when zoomed to small values, Final Cut Pro's Wind Blur does not match the video output. Maybe they could use my little zoomfactor trick. Unfortunately, this makes it hard to show side-by-side comparisons of Wind Blur and Joe's Motion Blur with the same settings. The differences illustrated below try to show the differences in the most objective manner possible, download the filters and try it for yourself. Four out of Five people surveyed thought my filter tasted better.

If you are curious about FXScripts and Final Cut Pro, I also wrote a page about Building Joe's Motion Blur with FXScript.