_RED

The _RED function returns the palette index or the red component intensity of a 32-bit image color.

Syntax

redIntensity& = _RED(rgbaColorIndex&[, imageHandle&])

Description

• rgbaColorIndex& is the RGBA color value or palette index of the color to retrieve the red component intensity from.
• The LONG intensity value returned ranges from 0 (no intensity, not present) to 255 (full intensity).
• imageHandle& is optional.
• If imageHandle& specifies a 32-bit color image, rgbaColorIndex& is interpreted as a 32-bit RGBA color value.
• If imageHandle& specifies an image that uses a palette, rgbaColorIndex& is interpreted as a palette index.
• If imageHandle& is not specified, it is assumed to be the current write page.
• If imageHandle& is an invalid handle, an ERROR Codes error occurs.
• If rgbaColorIndex& is outside the range of valid indexes for a given image mode, an ERROR Codes error occurs.
• Uses index parameters passed by the _RGB, _RGBA, _RGB32 or _RGBA32 functions.

Example(s)

• See the example in POINT.

See Also

• _GREEN, _BLUE
• _RGB, RGB32
• _LOADIMAGE