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

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