colormap-channel->greymap

Synopsis

(colormap-channel->greymap colormap channel)

Parameters

  • colormap
  • channel : either 0 (RED), 1 (GREEN) or 2 (BLUE)

Description

One single channel of a colormap is converted to a new greymap.

Side Effects

Return Value

The resulting greymap is returned.

Example

> (define g (grabber-create))
g
> (define cm (grabber-grab g))
cm
> (colormap-channel->greymap cm 0)
#<greymap orow:-1 ocol:-1 xres:-1 yres:-1 h:720 w:1280>
>