Color Appearance Effects

All nine color appearance effects change the "look" of your images. They can combine two images, alter certain colors, create multiple images, and break the images into moving boxes. All can add some real visual zest to your projects.

Using Blend to Combine Two Clips

As illustrated in Figure 13.3, this AE effect lets you blend two clips by letting a clip that's lower on the timeline show through an otherwise fully opaque clip.

Figure 13.3. Blend lets a clip that's on a lower video track show through a clip above it.

You select a specific video track ”from one to three ”for the clip you want to blend with the selected clip. Crossfade sets a relative percentage of opacity for the top clip and the lower clip. A setting of 100% displays only the top clip. 0% shows only the lower clip, and 50% sets each at 50% opacity.

Color Only, Tint Only, Darken Only, and Lighten Only each let different values of the lower clip show through.

For an unusual effect, use a graphic for one clip and a colorful video for the other. Selecting anything but Crossfade leads to some bizarre results. If you put the graphic on the top video track, use Color Only, and move the Blend with Original slider to zero percent, which converts the graphic to grayscale and colors it using the lower video clip.

Adjusting Colors with the Channel Mixer

You'll find Channel Mixer in the Adjust file folder (not the Channel folder). Once you drag it to the Effect Controls palette, as illustrated in Figure 13.4, you'll face more than the usual number of options. This is a characteristic of most of the AE effects in this hour . They tend to require plenty of user input.

Figure 13.4. The Channel Mixer gives you precise control over your clip's colors.

Channel Mixer lets you modify each color channel. You can map one color onto another and increase or decrease a color's values to create high-quality tinted images.

The default value is 100% of each color. Dragging the sliders or inputting specific values will lead to sometimes dramatic results. Negative numbers invert the color.

Using keyframes with distinctly different values leads to some unique, gradual color changes during your clip.

Adding Multiple Action Images Using Echo

Echo is an exciting effect (in the Time folder) with numerous possibilities. It layers multiple sequential frames of a clip to convert simple action into streaking, smearing, or a sequence. As Figure 13.5 demonstrates , you control Echo using five parameters:

Echo Time ” The time, in seconds, between echoes. Negative values create echoes from later frames, causing ghosting or streaking to follow the action. Positive values use earlier frames, laying those echoed images ahead of the action.

Number of Echoes ” The number of extra frames added to the original to make this effect. Two echoes create three images ”the original plus two other ( subsequent or preceding ) frames. The slider values go from 1 to 10, but you can type in a number up to 3,000! From what I've seen, any value greater than 10 creates only 10 echoes.

Starting Intensity ” The relative brightness of the first frame in the sequence. At the highest value (1), the first frame is at normal intensity. A setting of one-half (0.5) displays the first frame at half its regular intensity.

Decay ” Notes the decrease in intensity for each subsequent frame. A Decay setting of 0.5 means the first echo will be half as bright as the first, the second will be one-quarter (0.25) as bright, and the third will be one- eighth (0.125) as bright.

To create smooth streaking and trail effects, use a large number of echoes (eight or more) and a short echo time (one-tenth or so).

Echo Operator ” Indicates how Echo combines frames. Here are the options:

The Add option combines the echoes by adding their pixel values. If the Starting Intensity setting is too high, your action will turn into bright, white streaks.

To give the first frame and all echoes the same value while avoiding those bright white streaks, set Echo Operator to Add, set Starting Intensity to a value equal to 1 divided by the number of echoes, and set Decay to 1. For example, for four echoes, set Starting Intensity to .25 (1 / 4 = .25). A Decay setting of 1 means there will be no decay ”all echoes will have the same value.

Maximum uses the maximum pixel value from all the echoes, which emphasizes the brighter action elements.

Minimum uses the minimum pixel value from all the echoes, displaying only the darker values.

Screen is like Add but does not overload as easily.

The two Composite options are for video clips with alpha channels (this will not work on most video clips). The Composite in Back option layers them back to front, whereas the Composite in Front option layers them front to back.

Figure 13.5. Echo converts motion into streaks, smears, and repeated actions.

Echo is a special video effect. By default, it switches off any other effects applied before it to the clip. Those that come below it on the Effect Controls palette still work. However, there is a workaround: Create a "virtual clip." I'll explain this in detail in Hour 16, "Tips, Tricks, and Techniques: Part 1." A virtual clip is just like any other clip or set of clips with transitions, motion, and effects. You build it away from your project, usually on unused tracks. Then you select it using the Block Select tool and drag it to your project. Then you can add the Echo effect without switching off the other effects.

Building Borders Around Objects with the Find Edges Effect

Find Edges is the easiest to use of all this hour's AE effects. There are only two controls. I include it in this hour because it works so well. You'll find it in the Stylize folder. It locates elements in the image with obvious differences in contrast and color; then, as illustrated in Figure 13.6, it creates distinct dark edges on a white background. The slider lets you combine a percentage of the original image with the converted image. Invert swaps black and white, creating white lines for edges.

Figure 13.6. Find Edges creates what appear to be sketched outlines.

Here's one totally bizarre application of the Find Edges effect. Use it on any clip, add the Color Replace effect, and select any of the many black borders created by Find Edges. Replace that color with something distinct ”bright red for instance. Then click the Solid Colors check box to replace the black lines with the new color. Looks like you just strung everything with Christmas lights.

Adding Dazzle to Your Project with the Lightning Effect

Lightning is a wild and wacky effect (found in the Render folder). Lightning is reminiscent of QuickTime's Cloud and Fire effects in that it doesn't convert the image. Rather, it places a special effect over it ”in this case, a simulated flashing electric arc like those used in old monster movies.

As you'll see when you drag it to the Effect Controls palette, its creators went overboard in the number of options ”25 parameters! To avoid being equally guilty of overkill I won't go over all of them.

As I've demonstrated in Figure 13.7, you use its two crosshairs to set start and end locations for the lightning. Setting keyframes lets you alter those locations over the duration of your clip.

Figure 13.7. Experimenting with Lightning is great fun. Try a red/orange color scheme.

The many options let you set the size and intensity of the lightning. Increasing the number of segments, amount of branching, and level of detail make the flashes more jagged (kind of nastier looking). Choose any colors you like ”both the core and outside colors. The default white/blue scheme works well but red/yellow provides an evil, organic touch.

Breaking Images into Blocks with the Mosaic Effect

Mosaic is sort of like Pointillization with rectangles. You'll find it in the Stylize folder. As Figure 13.8 shows, you select the number of horizontal blocks and vertical blocks (rows and columns ) ”between 1 and 200 ”to create a collection of rectangles. The higher the number, the smaller the rectangles and the closer the image will match the original. At 200, it's simply jittery.

Figure 13.8. You can use Mosaic to create a faux transition.

The Sharp Colors check box creates a more distinct, clearly defined rectangle.

Use Mosaic as something like a transition. Using keyframes or simply the default start- and endpoints, start the "transition" near the end of the clip by setting both Horizontal and Vertical Blocks to 200. Then drop this setting to about 20 each at the end of the clip. Start the next clip at 20 and quickly build it to 200. Uncheck the Sharp Colors box; otherwise, the transition from 200x200 blocks to standard video will be somewhat abrupt.

Giving Your Clips That Old VHS Feel with Noise

You do what you can to create clean, sharp, noise-free video. So what does Adobe do? It includes this Noise effect in Premiere to give your videos that low-light, consumer, analog camcorder look. This effect is found in the Stylize folder.

The Amount of Noise slider sets the noise level by distorting or randomly displacing pixels. As illustrated in Figure 13.9, at a setting of 75%, depending on which boxes you've checked, your clip may become unrecognizable.

Figure 13.9. Setting a Noise value of 75% can obliterate a clip.

Checking the Use Color Noise box randomly changes the red, green, and blue values of the image's pixels. Unchecked means all color values change equally.

Checking the Clip Result Values box creates a more realistic Noise display by letting color values that reach their maximum value "wrap around" and start over at 0% noise. Leaving it unchecked means color values that "max out" stay at that maximum level, making some portions of your scene shimmer with noise.

To completely randomize Noise, turn on Use Color Noise and turn off Clip Result Values. To reproduce "true" noise, set the slider to about 20%, turn off Use Color Noise, and turn on Clip Result Values.

Giving Your Project Flash with the Strobe Light Effect

This effect, from the Stylize folder, opens the door to numerous creative possibilities. It works like a strobe light, flashing frames as your clip plays. Those frames can look like a super-bright strobe light or be black, transparent, or an inverse image.

The options, as illustrated in Figure 13.10, are listed here:

Blend with Original ” This option blends the Strobe Light effect with the original to adjust the intensity or brightness of the effect.

Strobe Duration ” Sets the length, in seconds, for each strobe flash. Less than a half second is most like a real strobe, but you may want a strobe to stay on longer to show the inverse image or another image below this clip in the timeline.

Strobe Period ” Sets the time, in seconds, between the start of subsequent strobes. Setting a strobe period of 2 seconds, for example, and a strobe duration of 0.5 seconds means you would see the strobe effect for a half second. Then there would be a 1.5-second break until the next strobe effect. If the strobe period is less than or equal to the strobe duration, then the strobe stays on all the time.

Random Strobe Probability ” Set at a value other than zero means the effect will have a more realistic feel. It'll cause strobing even if the strobe period is less than or equal to the strobe duration.

Strobe drop-down menu ” This menu has two options: Operates on Color Only and Makes Layer Transparent. A clearer way to state these options is Opaque and Transparent. If you choose Makes Layer Transparent, you can superimpose the strobe effect clip over another, revealing the lower clip during strobes. I'll cover transparency issues in Hour 14, "Compositing Part 1 ”Layering Images and Clips," and Hour 15, "Compositing Part 2 ”Alpha Channels and Mattes."

Strobe Operator ” Gives you extra control if you choose Operates on Color Only (opaque). Copy is the default setting. Subtract displays a black strobe screen, and Difference pops on an inverse image.

Figure 13.10. The Strobe Light effect opens up numerous creative possibilities.

For a little comic relief, use the Strobe Light effect with Strobe Operator set to Difference and Duration and Period set fairly low. The resulting strobe effect is reminiscent of a cartoon character sticking his finger in a light socket.

Using One Clip to Add a 3D Feel to Another Using Texturize

Here's another AE effect from the Stylize folder with tons of possibilities. It uses two clips. As demonstrated in Figure 13.11, Texturize embosses the lower clip on the timeline and lets that 3D feel show through on to the other clip.

Figure 13.11. Texturize embosses one clip and imparts that 3D feel to a clip above it on the timeline.

Light Direction and Texture Contrast set the depth of the embossing. Texture Placement offers three options: Tile Texture, Center Texture, and Stretch Texture to Fit. I tried them all and they all created the same effect (perhaps it was a bug in my pre-beta release of Premiere). Tile Texture should apply the texture repeatedly over the clip, Center Texture is supposed to put the texture in the middle, and Stretch Texture should spread the texture to the corners of the clip.

The name Texturize is too narrow. Yes, you can use a clip with obvious texture ”rug, sand, or rippling water ”and impart that feel to another clip above it on the timeline. But there are many other uses. You can bring up an embossed version of your logo beneath a product shot or place one distinctly different setting under another. How about embossed waving palm trees behind a frozen arctic tundra?

Adobe has not documented this, but Texturize apparently is one of those effects that will not work with motion settings. Therefore, if you want to move around your embossed logo under another clip, you'll need to create that moving logo using motion settings and turn it into a virtual clip. As mentioned earlier, I'll cover this topic in Hour 16.