Part 3: Avoiding the Icy Sea

OK, so maybe you don't like all this ICC color management stuff. Maybe you long for the simplicty of eLin.* Maybe you want parallel color pipelines in all your floating-point comping apps.

Remember this article? It described using the eLin color model in Shake, and this one talked about Fusion. Now you can use this same true floating-point implementation of the eLin color model in After Effects 7 as well. The Anim Presets below follow the same naming convetion as the Shake and Fusion Macros, and do exactly the same things. To work with them in AE7, leave color management off (set Project Working Space to None), and set up Guide Adjustment Layers (AKA LUT layers) to hold your lin2vid Presets, just like you did for eLin.

eLin_float.zip (17.1kB zip file UPDATED 2/11/06)

* No, I know you don't.

Linear Color Workflow in AE7, Part 2

When last we met, you had established a linear color profile as your project working space.

Why exactly did you do that? Because you wanted to process your pixels in linear-light, for a more photographic look to your basic compositing operations. You want color mixing free of edge artifacts, you want basic color corrections to yield organic results, you want simple blurs to look like smeared light, and you want to be able to speak and work in photographic terms, such as "a stop darker" and "18% gray."

You converted your pixels into your linear color space using Adobe's ICC color engine, which has been expanded to support floating-point for PSCS2 and now AE7.

So now what?

Just like with eLin, you should immediately see that even the most basic compositing operations look better. A simple A over B comp will have better edge blending and more photographic transparency. A layer in Add mode will look exactly like a double-exposure.

A layer in Screen mode will break. Like it says in the eLin docs, stay away from Screen. Add is the new Screen. Lemme just tip a 40 real quick for Screen. You got us through some 8-bit times, homie.

In linear light, basic color corrections become very useful and lovely, as we discussed here. One great example of this is the Exposure effect. It offers a slider for increasing or decreasing the exposure of your image in stops. You don't need to worry about the status of the "Bypass Linear Light Conversion" checkbox at the bottom, since you have a linear Project Working Space.

If you apply Levels to your linear float layers, bear this stuff in mind. Reach for gamma last, not first. Gain is your best friend, and Output White is Gain. And remember to un-check the Clip White checkbox! It defaults on for backwards compatibility, but I wish it didn't.

Since dialing in R, G and B gain is the most lovely way to color correct in linear float, I created a simple Anim Preset that allows you to do it using a color swatch rather than the Levels UI. Apply it to a layer and experiment with different colors in the swatch. Don't touch the Levels effect at all. Just like with our hacked 3-way Color Corrector, you can scrub the swatch in the timeline to adjust its hue and saturation, giving you interactive control over this color correction tool. Cool!

ColorLevels.zip (4kb, unzip to your Presets folder)

By the way...

...that last post was also a tutorial on how to set up ICC color management in After Effects 7.0. Even if you don't have any interest in working in linear-light, you will still need to select a Project Working Space if you want to utilize AE's ICC display correction, and then you'll need to use the Color Profile Converter effect to bring footage into that color space (if it isn't there already).

For example, if you're working in NTSC video, you could set your Project Working Space to SMPTE-C. Any video footage you import will be assumed to be in this space, and will require no Color Profile Converter effect. But if you wanted to include some artwork from a client that was tagged with Adobe RGB profile, you would apply the Color Profile Converter effect and set Input to Adobe RGB and leave Output at Project Working Space.

Or you could do the opposite. You could select the profile with the wider gamut, Adobe RGB, as your Project Working Space. There are a few reasons why this might be a better plan. You'd then leave the artwork alone and use the Color Profile Converter effect to convert your video footage from SMPTE-C to Project Working Space.

Either way you'd have proper display compensation (i.e. things will "look right") on your calibrated monitor, and you can tell your client that you are faithfully preserving their logo colors on the .01% of TVs that are properly calibrated.

Not easy, kinda scary, but quite useful.

Linear Color Workflow in AE7, Part 1

When AE7 was announced, I posted a list of ten cool things you can do with it. Let's dive right in to one of the biggest, which is that you can scrap eLin and work in a true linear floating point color space.

Warning: The following may have the effect of making AE7's 32-bit float mode sound more complicated than it inherently is, so let me stress that none of what I describe here is strictly necessary for enjoying AE7's new color mode. If you want to experiment with the increased quality and overbright performance of float, just pop your project into float mode and start experimenting. But if you've warmed up to a linear color workflow, perhaps via eLin or similar techniques, then read on for the AE7 equivalents.

The first thing you'll note about AE7's Project Settings dialog is that it has grown substantially. There's now a pop-up for your Project Working Space. This is a the first baby steps of ICC color management in AE. It's not a complete implemengtatjon in 7.0, but it is usable, and it's perhaps the easiest way of working in a linear color space.

What you're going to do is select 32 bits per channel (float), and then select a linear color profile as your Project Working Space. The problem is that no linear, or gamma 1.0 profiles ship with AE7. So quit AE and download this file:

linearProfiles.zip (4kb zip file)

Unzip it and add the two files contained within to your collection of ICC profiles. On the Mac, that's:

~/Library/ColorSync/Profiles/

On Windows, it's:

C:\Program Files\Common Files\Adobe\Color\Profiles

Restart After Effects, create a new project, and access the Project Settings Window. Select 32bpc mode, and then select one of these two linear profiles as your Project Working Space.

How do you choose between them? Good question, one that entire books have been written to address for the Photoshop community that's been dealing with the joys and pains of ICC color management since before we had RAM preview. You could do worse than to go read two or three of those books right now. If, afterwards, you still have the will to live, pick one of the two profiles at random and plow ahead.

You now have a floating-point project with a linear Working Space. Import a familiar image, preferably one with an ICC profile embedded. Add it to a comp and view the result.

The image will look too bright. Why? Well, AE doesn't recognize the embedded profile. That's right, here's where AE's fledgeling color management leaves us hanging. AE is assuming that the imported footage is already in the Project Working Space. It's not. It's gamma-encoded, so it looks too bright. We have to manually convert the gamma-encoded colors in our image to the linear Project Working Space.

We do this with Effect > Utility > Color Profile Converter. Apply this effect to your image and observe the Effects Controls. You'll see pop-ups for two profiles, Input and Output. The idea here is that we convert the pixels from the image's native color space to that of the project. So set Input Profile to the correct profile for the image, the one embedded within it. Leave Output set to Project Working Space.

Now the image in the comp viewer should look correct. You've converted your pixels to linear light values and your linear image is not only being gamma corrected for display, it's also being display compensated using ICC color management. In other words, for the first time ever, and whether you like it or not, this image will look the same in After Effects as in Photoshop.

There's much more to discuss, but we had to start somewhere. Please comment, query, cry, or acquiesce.