Image

Glossary

Alpha

A pixel has red, green, and blue values; a pixel also has an alpha value. The alpha value refers to the transparency value of the pixel. A 0 value means the pixel is transparent; at the other end of the scale, at 255, a pixel is fully opaque.

Not all file formats support transparency. PNG, PSD, TIF, and XCF all support transparency.

Alpha Channel

An alpha channel is used to represent the alpha value in an image.

Aspect Ratio

The aspect ratio of an image is the ratio between the width and height of an image. The first number refers to the width.

Brightness

Brightness refers to the amount of light in a color. If a red look unnaturally ...

Get GIMP for Absolute Beginners now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.