ATI Technologies RADEON MAC EDITION, 107-40214-20 manual Glossary

D Glossary

Alpha	When an image has an alpha value for each pixel, this tells
blending	how much to blend the colors from the image with the
	background colors. The lower the alpha values the more
	transparent the image looks.
Anti-aliasing	Method used to remove the jagginess of an image. When
	anti-aliasing is used, the edges of an image appear smooth
	and usually somewhat blurry.
Back buffer	A type of offscreen memory used to provide smooth
	video and 2D graphics acceleration. This technique uses
	two frame buffers, often referred to as "double-buffering".
	While one buffer is being displayed, a second buffer of the
	same size, the "back" buffer, holds the frame being worked
	on.
	Once a new frame is ready in the back buffer it is copied to
	the front buffer - the display screen. In this way, you will
	only see complete, smooth frames, and not the operations
	performed on them.
	In order to increase performance, all memory used for
	back buffers are on your ATI graphic accelerator card.
Bilinear	When texture mapping is performed an image can become
Filtering	very “blocky” or “pixelated” when the texture is viewed
	close up. Bilinear filtering samples four texture pixels,
	takes the weighted average of these pixels and applies the
	average of these “texels”. This blended color is used to
	provide a smoother looking texture.
Bitmap	A bitmap is a graphics or character representation
	composed of individual pixels, arranged horizontally in
	rows. A monochrome bitmap uses one bit per pixel (bpp).
	Color bitmaps may use up to 32-bpp, depending on the
	number of colors desired.
Buffers	Your ATI accelerator card includes on-board memory
	which is used in a number of ways. Buffers are portions of
	this memory used as temporary storage on your card. One
	large buffer is always used to display the screen you see;
	this is the “display buffer”. The rest of offscreen memory
	is used by applications as back buffers, z-buffers, and
	texture buffers.

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