Programming Web Graphics with Perl and GNU Softwar

Name

Opaque( ) — globally change a color

Synopsis

$image->Opaque(color=>color,

                     
pen=>color)

Opaque( ) changes the entry corresponding to the color parameter in the image’s colormap to the pen color. To change all the white pixels in an image to red, for example, use:

# Change all white pixels to red
$image->Opaque(color=>'white', pen=>'red');