Create animation on your videos

Adding effects
Beyond using filters to produce effects, you can add objects to frames by drawing on them or manually edit and add to the existing image.

As with all animation, you need to think about time and plan carefully. Simple effects often work better than complicated ones and are easier to produce.

For example, you might want to have a light bulb appear over someone’s head when they get a bright idea (I’m not going to let a cliché get in the way of a good example).

This probably only needs to appear for a few seconds so you’ll have to animate 50 frames. But the exclamation need not be unique on each one. Five slightly different exclamations would be sufficient to give it a bit of wobbly motion. If your image editor can display animation, test it out.

When you are happy with it, paste frames 1 to 5 of the animation on to frames 1 to 5 of the video still image sequence. Then repeat the process, pasting the animation into the next five frames and so on, until all 50 frames are complete.

A good shortcut when producing this type of movie is to use animated Gifs. You need an application that allows you to extract the individual frames. There’s no shortage of free animated Gifs on the web and it’s surprising how often something that looks cheesy on a web page works well when juxtaposed with real-life video.

Rotoscoping that involves introducing moving objects (such as lightsabers) can be more demanding in terms of the techniques involved and time taken. I’ve produced a short clip that simulates a retinal scan machine – a security device that has enjoyed popularity in movies of the past few years including Mission Impossible, Goldeneye and Minority Report. The protagonist usually succeeds in getting past the device, in some cases by resorting to measures such as eyeball transplants.

In this clip, you can see the red scan laser as it passes over the eye from top to bottom.

There are two things that need to be done to make this clip work. First, the scan laser needs to move smoothly from the top of the screen to the bottom, passing over the face and eye as it does so. Second, as it passes over the actor’s face, the laser has to deform, following the facial contours, so that it looks like it’s projected rather than added digitally later on.

Neither of these tasks is especially difficult, but the need to apply them individually to 50 frames to produce the two-second effect is quite time consuming. This clip took me about four hours. The first step was to apply a photo filter to each frame to generate the blue ambient lighting and provide a contrast for the red laser.

Action!
Making the laser was simple enough – it’s a feathered rectangular selection filled with red and with the Motion Blur filter applied. Motion Blur is a useful filter for rotoscoping. If you examine individual frames of video you’ll see that moving objects are often blurred due to the slow shutter speed. Pin-sharp computer-generated graphics can look artificial by comparison and the Motion Blur filter makes them look more natural.

To animate the laser, I pasted it in the same starting position on each frame and used Photoshop’s Offset filter to move it downwards in multiples of six pixels, ie six pixels down on the second frame, 12 on the third, 18 on the forth and so on.

Making the laser conform to the facial contours was achieved using a displacement map. Displacement maps are black and white images that, when used with the Displacement filter, move pixels in the target image depending on the greyscale value of the corresponding pixel in the map.

I created a displacement map for each frame from the frame itself by changing the mode to greyscale and applying a little Gaussian Blur. Then I applied each frame’s individual map using the Displace filter. Re-importing frames is a straightforward step in Premiere Elements 2.0 that automatically combines still image sequences into a single video clip.

If your video-editing application can’t export a sequence of frames, you’ll have to export each frame individually. Although this may take time, I can’t think of any video-editing apps that don’t allow you to ‘grab’ and export single frames.

Getting them back in is more of a problem. Most video editors allow you to import single still images for titling, slideshows and movie projects. Usually there’s a default duration for clips added to the timeline.

If you can specify this in frames, set it to one. You might find you need to set the default still image duration prior to importing the stills. Providing you’ve sequentially numbered the files, you should be able to drag the whole lot onto the storyboard/timeline and they’ll appear in the correct order.

Akvis Sketch
If you want to achieve rotoscope-style effects but lack the drawing skills and can’t achieve the results you want with your image editor’s existing filters, you might find a plug-in called Akvis Sketch useful.

I have yet to use it, but a press release announcing the release of version 2 appeared in my inbox just as I was completing this month’s column. Judging by the examples on the Akvis website it’s straightforward to use and produces natural hand-drawn-style effects.