colormap-difference

Synopsis

(colormap-difference colormap1 colormap2)

Parameters

  • colormap1
  • colormap2

Description

This procedure creates a new colormap containing the difference for each color channel of each pixel. The two suppied colormaps need to have the same dimensions, otherwise an error is signalled. The difference for one single channel is computed by subtracting the smaller value from the larger.

Side Effects

Return Value

Example

> (colormap-difference frame1 frame2)
#<colormap orow:-1 ocol:-1 xres:-1 yres:-1 h:480 w:640>
>