Description
int
imagecolortransparent ( int im [, int col])
ImageColorTransparent() sets the transparent
color in the im image to
col. im is the
image identifier returned by ImageCreate() and
col is a color identifier returned by
ImageColorAllocate().
Note:
The transparent color is a property of the image, transparency is not a
property of the color. Once you have a set a color to be the transparent
color, any regions of the image in that color that were drawn previously
will be transparent.
The identifier of the new (or current, if none is specified)
transparent color is returned.