Lingo Dictionary > D-F > extractAlpha() |  |

extractAlpha()

Syntax

    imageObject.extractAlpha()

Description

This function copies the alpha channel from the given 32-bit image and returns it as a new image object. The result is an 8-bit grayscale image representing the alpha channel.

This function is useful for downsampling 32-bit images with alpha channels.

Example

This statement places the alpha channel of the image of member 1 into the variable `mainAlpha`.

    mainAlpha = member(1).image.extractAlpha()

`setAlpha, useAlpha`