Wikimedia
Wikipedia: Raster Graphics (Bitmap)
Encyclopedia entry that defines what a Raster graphic (Bitmap) is and explains how it works. Includes a nice illustration and an example of how a bitmap picture is constructed. Links to related information are available.
TeachEngineering
Teach Engineering: What Makes Up a Color?
As a part of the research and revise step of the Legacy Cycle, this lesson provides students with information they will need later on to be able to average pixels to simulate blurring in the peripheral plane of vision. Students learn why...