What is Deep Color?
When HDMI 1.3 came out, one of the major new capabilities of the cable was that it supported Deep Color and xvYCC. Deep color, along with xvYCC, theoretically makes the color on your display more realistic. Deep color increases the available bit depth for each color component, and xvYCC makes the overall color gamut larger. Okay, great. But what does that mean?
Basically, all displays use the primary colors (red, green, and blue) to create all of the colors you see on the screen. “But wait…” you might say, “don’t you mean red, yellow, and blue?” After all, didn’t we all learn in the first grade that those are the primary colors? Well, that depends. For finger paints and crayons that is true. That’s because finger paints and crayons (and anything else that is drawn, painted or printed on a page) use subtractive color. With subtractive color, the material on the page (like your finger paint) absorbs light and reflects back only the color that you see. Additive works the opposite. Color is created using specific light wavelengths. Short version: with subtractive color light is reflected, and with additive color light is created directly. Displays (like monitors, TVs, and projectors) use additive light, so we use RGB.
By blending the three primary colors you can make more colors, and by varying the intensity of each color, you get different shades.
The x’s and y’s of Color
Color is very subjective. What looks like blue to you might be purpley-blue to me. If there were no standard in RGB color, every video game, TV show, and movie would each look a little different. That’s why, back in 1990, a bunch of really important and official people got together and created standard coordinates for red, blue, and green. Yup, I said coordinates. They used a diagram which mapped colors using a grid. You might be familiar with this idea if you’ve ever used photo editing software. By assigning coordinates to the colors, each display, camera, etc. would all reproduce the exact same colors within that triangle of red, blue, and green.
So What is xvYCC?
The purpose of xcYCC was to expand the color gamut, and thereby the color possibilities. That gives you access to deeper colors across the board. And that brings us to Deep Color. To understand why Deep Color is a big deal, we need to talk about color depth, also known as bit depth.
What is Color Depth?
Color depth or bit depth refers to the number of bits (a bit is a basic unit of information) used to indicate the color of a single pixel in an image. Put simply, as the number of bits increases, the number of possible colors increases as well, making the image look better. To get an idea, take a look at the comparison below:
24-bit color, or “true color,” is still very common in HDTVs and monitors today. It supports 24-bit color for the three RGB colors. That means there are 256 different shades of red, blue, and green for a total of at least 16, 777, 216 different variations. That’s a lot of color. When HDMI 1.3 came out, it allowed for the use of Deep Color, which takes things a step further.
So, What is Deep Color?
Deep color supports 30/36/48/64-bit color for the three RGB colors. That puts the number of colors available into the billions. For example, 36 bit color allows for 68, 719, 476, 736 different color variations. And since it also supports xcYCC, there are even more color options to choose from. That all translates to sharper, more vivid images.
But, in order to have deep color, everything needs to work with it, from your source, to your cable, to your display. If any of these elements don’t support Deep Color, you won’t get the benefit.
Luckily it’s not hard to find equipment that supports Deep Color. Already the PlayStation 3, many DVD players, and many graphics cards support Deep Color, as well as many different displays.
True color still looks good, to be honest there is still some debate on if there is any noticeable difference between true color and Deep Color. After all, the human eye can only discern around 10 million colors. But, adding all of those colors can’t hurt. However, the biggest argument in favor of Deep Color is the issue of color banding. Color banding is when there isn’t enough pixel information to successfully recreate gradients, which creates bands of color. By having way more colors, Deep color greatly reduces banding.