The Moving Picture: Color Me Impressed
Posted Nov 1, 2003

I have to admit that I was wrong. When I started reviewing DVD applications some six years ago, it didn't take a visionary to see that authoring had to get a lot easier for DVD to improve upon the very marginal successes of VideoCD and CD-i. A lot of terminology had to go—Video Title Sets and Video_TS folders, program chain groups and the like— and user interfaces had to do a lot more of the work to entice broader usage. But all these transgressions against authoring accessibility paled against the real poster child for all that was wrong: "Color Mapping."

Sure, the basic concept of Color Mapping is simple: make a specific color in your menu turn into another color when the viewer's cursor/ remote "selects" and then "activates" a button. But which color are you mapping: the color you're coming from or the color you're going to? Why do I map the color in "Normal" when nothing has happened yet? All of a sudden there's this matrix of twelve colors, each with a pull-down menu with more colors. Where did they all come from? And then there's this whole transparency thing. What becomes transparent: the color I'm substituting or the one I'm substituting for?

Color Mapping can seem like an old grade-school word problem. You know the kind: if you have eleven apples and three get eaten by worms and seven are green and someone gives you five more…Or, if you're stuck driving behind a truck going 35 mph and you have 72 miles to go, but the truck turns off after 26 miles…

I thought Color Mapping was on the way out several years ago with the first application to break the $10,000 price barrier. Minerva's Impression (now sold by Pinnacle Systems for less than $200) introduced a clever way of building menus and sub-pictures in Adobe Photoshop by leveraging Photoshop's layers. You had to be very exact about naming layers, but once inside Impression the buttons' states (normal, selected, or activated) were ready to go. No Color Mapping!

Astarte soon did them one better in DVDirector by randomly assigning Photoshop layers to button states within the authoring interface. That functionality still exists in its descendant, the recently transformed DVD Studio Pro 2.

But so does Color Mapping!

What happened to ease of use along the way? Applications like DVD Studio Pro 2 and Adobe Encore are just the kind of thing (for the most part) I dreamed about back in those early DVD days. They are capable, modestly priced applications that make designing and integrating almost blissfully easy (relatively speaking, of course). They hide the more esoteric aspects of authoring and still offer rich functionality. So, why do they still have Color Mapping?

Keep in mind that abstracted tools like DVD Studio Pro 2 and Encore are writing discs to interact with DVD players and answer to the DVD spec just like the tools introduced six years ago; we just don't see it. We aren't doing the same job, but they are. So how does this "abstracted," Photoshop-assisted approach affect the functionality of DVD titles created with it? Using Photoshop layers is clever for authoring, but potentially less fluid for playback. Why? Each Photoshop layer used as a sub-picture is actually encoded by the DVD engine into a separate JPEG file.

When a user changes the button state from normal to selected to activated, DVD players have to swap an entire full-frame JPEG, which is a potentially clumsy operation for low-memory, CPU-less devices. The relative genius of Color Mapping is that the player need only swap a set color within a JPEG and not load a new file. That's a faster, more responsive user experience. And it turns out, like those word problems from grade school, once you figure what's going on, the "math" is really pretty simple.

The trick with Color Mapping is preparation: designing the changeable areas (in the buttons or highlights) of menus with exact RGB color or grayscale values that can be identified specifically in Color Mapping. They don't even have to be the colors you want viewers to see, although they can be. They just act as hot zones or punch holes into which the DVD player can substitute other colors.

After telling the authoring interface which color(s) will be overlaid, you assign new colors (here comes that matrix) that will be seen in the different button states. The matrix is only complicated because you have the opportunity to assign new colors to all three states for each button (normal, selected, activated).

Admittedly, the DVD spec limits you to a palette of 16 colors per menu, an apparent hurdle for color-design jocks. But the DVD spec gives you the ability to set opacity levels for each newly assigned color (from completely transparent, thus showing your original color, to fully opaque) and the chance to blend colors. You can use up to three different color sets in a single menu and have multiple simultaneous visual elements changing with each move of the player's cursor. It's really a designer's boon, and—even better—it tends to yield very professional end-user performance results.

While Video Title Set (VTS) groupings are now just dragged and dropped and button navigation is often automatically generated, Color Mapping remains. And it remains in products designed for business users and independent videographers affording them same professionalism as top-tier tools with less accommodating interfaces. So, I was wrong. Color Mapping has to stay.

On the other hand, the new version of Photoshop CS has a new feature called "Layer Comps" that automatically generates layers and visual layer combinations. It really wouldn't be that hard, it seems to me, for Adobe to tie that feature to Encore, thus doing all that matrix programming for you. Hmmm…