1. A method performed by a computing device, the method comprising: processing image data to form a plurality of pixels, wherein each pixel in the plurality of pixels has associated therewith one or more color channels that define a resulting color for said each corresponding pixel in the plurality of pixels; using the processed image data to determine a graphics primitive type that is associated with a set of pixels in the plurality of pixels; causing at least one additional color channel to be associated with each pixel in the set of pixels, the at least one additional color channel not being relied on to define pixel color, such that each pixel in the set of pixels has associated therewith (1) one or more color channels that define pixel color and (2) at least one additional color channel that is not being relied on to define pixel color; and assigning the graphics primitive type to each pixel in the set of pixels by causing the at least one additional color channel of each pixel in the set of pixels to be mapped to the graphics primitive type, whereby the computing device supports an image format that describes a type of content being described by each pixel in the set of pixels through assignment of the graphics primitive type to the at least one additional color channel for each pixel in the set of pixels.