With the timeline, you can add special effects and image processing filters to an animation or sequence of frames, and even animate their parameters via keyframes.

A keyframe means that all the values for the frames inbetween keyframes will be extrapolated for you. Keyframes show up as a yellow handle (it almost looks like a key) on the top of the interactive part of the timeline.

You can save one level of undos, so you can restore your changes if you decide you don't like them. To do this, be sure the “Save undo” checkbox is checked before you apply any filters.

The timeline has a few useful buttons, such as being able to play the animation directly from the timeline. You can zoom in and out on your keyframes for better precision, and you can copy and paste keyframes.

This is the area that represents the frames in your animation.  It looks pretty blank if you have no animation loaded.

You can create an animation by loading one, or initializing from the animation menu.  Once an animation is created, you will see sections in this area that represent the frames of your animation.

Use the orange bar to scrub through your animation, or you can use the play and stop buttons to view your animation.

Use this “Filters” drop-down list to select the filter you want to apply to your frames.  The list is categorized into sections to make the filters easier to find.  They are organized in the same way that filters are organized in the main program.

Under the Adjust section, you will find the Color adjustment filter...

The controls for this filter will appear to the right.  They will be different for each tool.

Once a keyframe is created, it's not fixed in stone. You can move keyframes around on the timeline by clicking and dragging them.

At a basic level, the Timeline can be used to simulate different types of lenses or medias, such as this black and white film look.  It was achieved by converting the frames to grayscale, then adding a slight sepia color tone, and adding film grain.

Here, a soft and dreamy effect is created with the light diffusion filter.  Love scenes and anime make heavy use of light diffusion.

There are a number of other ready to use filters that simulate the type of  filter you can put over a camera lens.  Here, the sunset filters makes your images look as if they were shot late in the day.

You can even simulate the elements, like this rain created by cranking up the values on the snowfall filter.

The Timeline can also be used to create traditional filmic effects like fade-ins and outs by keyframing the value from 0 to full value.

Panning and zooming is possible in a video by using the transform filter.  This can be used to simulate a zoom lens.  Beware that zooming in can make your images blurry.

The Alpha channel can be used freely with the timeline to limit the effects to a portion of the image.  Here, the linear alpha fader was used to fade out the alpha toward the bottom of this image.  A 'Map to gradient' filter was them applied to give a blistering hot look to the sky.

The swap image can also be used for a lot of interesting things.  Here, it was used to create a simple vignette.