Raster images in display systems such as X11 or Windows are generally represented using very system-dependent representations. These representations are deeply dependent on the display system configuration, forcing you to write display depth dependent code. The IlvBitmapData class allows you to describe raster images using a common portable API. IlvBitmapData is the base class of three subclasses that allow management of indexed images, true color images with alpha channel, and black and white images commonly used for masking and clipping. Bitmap data are managed like resources and can be locked/unlocked. This class is generally not used directly. The IlvBitmapData class manages memory, reference counting, and generic access to pixels of the image. It also provides access to basic image processing methods such as stretching. Rogue Wave® Views also provides functionality for converting true color images to indexed images, a process known as quantizing (see IlvQuantizer: The Image Color Quantization Class). You also have access to the full SVG specification filters, allowing for very advanced image processing features (see Chapter 5).