A color space in ImageGear describes the channels present in an image. The most important part of this description is the color channel configuration. This includes how many color channels there are and how these channels are used to describe colors, which is the usual informal concept of a color space. For example, in the RGB color space there are three channels (red, green, blue) whose values are combined to form colors. In the indexed color space there is one channel which consists of index values into an associated color palette.

In ImageGear, the concept of a color space is extended to also include information about other types of channels besides color, such as alpha and extra channels. An ImageGear color space ID is a bit field which can combine values from the enumIGColorSpaceIDs enumeration defined in accucnst.h.

For example,

• A simple RGB image would be:

IG_COLOR_SPACE_ID_RGB

• A grayscale image with an alpha channel and no extra channels would be:

IG_COLOR_SPACE_ID_Gy | IG_COLOR_SPACE_A

• An RGB image with a premultiplied alpha channel and three extra channels would be:

IG_COLOR_SPACE_ID_RGB | IG_COLOR_SPACE_ID_P | IG_COLOR_SPACE_ID_Ex