RGBA Color Space
RGBA stands for red green blue alpha. While it is sometimes described as a color space, it is actually simply a use of the RGB color model, with extra information. The color is RGB, and may belong to any RGB color space, but an integral alpha value as invented by Catmull and Smith between 1971 and 1972 enables Alpha compositing. The inventors named alpha after the Greek letter in the classic linear interpolation formula αA + (1-α)B.
The alpha channel is normally used as an opacity channel. If a pixel has a value of 0% in its alpha channel, it is fully transparent (and, thus, invisible), whereas a value of 100% in the alpha channel gives a fully opaque pixel (traditional digital images). Values between 0% and 100% make it possible for pixels to show through a background like a glass (translucency), an effect not possible with simple binary (transparent or opaque) transparency. It allows easy image compositing.
PNG is an image format that uses RGBA.
Read more about RGBA Color Space: ARGB, RGBA Hexadecimal
Famous quotes containing the words color and/or space:
“When a bachelor of philosophy from the Antilles refuses to apply for certification as a teacher on the grounds of his color I say that philosophy has never saved anyone. When someone else strives and strains to prove to me that black men are as intelligent as white men I say that intelligence has never saved anyone: and that is true, for, if philosophy and intelligence are invoked to proclaim the equality of men, they have also been employed to justify the extermination of men.”
—Frantz Fanon (1925–1961)
“There is commonly sufficient space about us. Our horizon is never quite at our elbows.”
—Henry David Thoreau (1817–1862)