Digital Color

Now that you're working on your Color Assignment, it's a good time to stop and review what it is that makes a digital photo digital...

Your image is mapped and encoded in “pixels”--those little squares of color that can be displayed on a monitor (or printed on paper).

Each pixel is assigned a number that will be communi- cated to the computer in a language that uses binary code (all ones and zeros).

You read these numbers in a simpler “human” language, however, such as “html.” HTML is a coding language for the RGB color system used on the web.

An HTML color is communicated to you in a "hexidecimal" number system. Each color code contains the prefix "#" followed by 6 letters and/or numbers.  (The hexadecimal numeral system  would be in what mathematicians call base 16,  using the 10 digits + the first 6 letters of the English alphabet.)

00 is the least and FF is the most intense "percentage" of red, green, or blue. There are, then, 16 levels of intensity for each of the three colors.

The first two symbols of an html number code represents the intensity of red. 

The third and fourth represent green

The fifth and sixth represent blue.

Example: #FF0000 - tells your browser to show a maximum of red and no green or blue. The result is of course pure red color.    

Combining the various intensities of red, green and blue we can mix a wide range of colors. The HTML you're familiar with uses a 6-bit (256-color) coding system, but with 24-bits the total number of colors capable is given as "millions" (16,777,216 to be exact, though not all browsers or all monitors will "decode" that many safely). The 256 colors are sometimes referred to as "web-safe"--meaning they can be decoded by most browsers on most monitors and will safely "dither" (not pixilate oddly) when displayed. However, as of 2011^[update], personal computers typically have 24-bit (TrueColor) and the use of "web-safe" colors has fallen into practical disuse. Even mobile devices have at least 16-bit color, driven by the inclusion of cameras on cellphones. Some Tablet computers, such as the iPad, also have 24-bit resolution capabilities. The more bits that are used per pixel, the finer the color detail of the image. However, increased color depths also require significantly more memory for storage of the image, and also more data for the video card to process, which reduces the possible maximum refresh rate.

To learn more about web colors, click to navigate to this wikipedia article: http://en.wikipedia.org/wiki/Web_colors

To learn more about monitor resolution visit: http://thescreamonline.com/technology/monitor/monitor_res.html